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guestfs

NAME

guestfs - Library for accessing and modifying virtual machine images

SYNOPSIS

  #include <guestfs.h>
  
  guestfs_h *g = guestfs_create ();
  guestfs_add_drive (g, "guest.img");
  guestfs_launch (g);
  guestfs_mount (g, "/dev/sda1", "/");
  guestfs_touch (g, "/hello");
  guestfs_umount (g, "/");
  guestfs_sync (g);
  guestfs_close (g);
 
  cc prog.c -o prog -lguestfs
 or:
  cc prog.c -o prog `pkg-config libguestfs --cflags --libs`
 
 

DESCRIPTION

Libguestfs is a library for accessing and modifying guest disk images. Amongst the things this is good for: making batch configuration changes to guests, getting disk used/free statistics (see also: virt-df), migrating between virtualization systems (see also: virt-p2v), performing partial backups, performing partial guest clones, cloning guests and changing registry/UUID/hostname info, and much else besides.

Libguestfs uses Linux kernel and qemu code, and can access any type of guest filesystem that Linux and qemu can, including but not limited to: ext2/3/4, btrfs, FAT and NTFS, LVM, many different disk partition schemes, qcow, qcow2, vmdk.

Libguestfs provides ways to enumerate guest storage (eg. partitions, LVs, what filesystem is in each LV, etc.). It can also run commands in the context of the guest. Also you can access filesystems over FUSE.

Libguestfs is a library that can be linked with C and C++ management programs (or management programs written in OCaml, Perl, Python, Ruby, Java, PHP, Haskell or C#). You can also use it from shell scripts or the command line.

You don't need to be root to use libguestfs, although obviously you do need enough permissions to access the disk images.

Libguestfs is a large API because it can do many things. For a gentle introduction, please read the ``API OVERVIEW'' section next.

API OVERVIEW

This section provides a gentler overview of the libguestfs API. We also try to group API calls together, where that may not be obvious from reading about the individual calls in the main section of this manual.

HANDLES

Before you can use libguestfs calls, you have to create a handle. Then you must add at least one disk image to the handle, followed by launching the handle, then performing whatever operations you want, and finally closing the handle. By convention we use the single letter "g" for the name of the handle variable, although of course you can use any name you want.

The general structure of all libguestfs-using programs looks like this:

  guestfs_h *g = guestfs_create ();
  
  /* Call guestfs_add_drive additional times if there are
   * multiple disk images.
   */
  guestfs_add_drive (g, "guest.img");
  
  /* Most manipulation calls won't work until you've launched
   * the handle 'g'.  You have to do this _after_ adding drives
   * and _before_ other commands.
   */
  guestfs_launch (g);
  
  /* Now you can examine what partitions, LVs etc are available.
   */
  char **partitions = guestfs_list_partitions (g);
  char **logvols = guestfs_lvs (g);
  
  /* To access a filesystem in the image, you must mount it.
   */
  guestfs_mount (g, "/dev/sda1", "/");
  
  /* Now you can perform filesystem actions on the guest
   * disk image.
   */
  guestfs_touch (g, "/hello");
  
  /* You only need to call guestfs_sync if you have made
   * changes to the guest image.  (But if you've made changes
   * then you *must* sync).  See also: guestfs_umount and
   * guestfs_umount_all calls.
   */
  guestfs_sync (g);
  
  /* Close the handle 'g'. */
  guestfs_close (g);
 
 

The code above doesn't include any error checking. In real code you should check return values carefully for errors. In general all functions that return integers return "-1" on error, and all functions that return pointers return "NULL" on error. See section ``ERROR HANDLING'' below for how to handle errors, and consult the documentation for each function call below to see precisely how they return error indications.

DISK IMAGES

The image filename ("guest.img" in the example above) could be a disk image from a virtual machine, a dd(1) copy of a physical hard disk, an actual block device, or simply an empty file of zeroes that you have created through posix_fallocate(3). Libguestfs lets you do useful things to all of these.

You can add a disk read-only using ``guestfs_add_drive_ro'', in which case libguestfs won't modify the file.

Be extremely cautious if the disk image is in use, eg. if it is being used by a virtual machine. Adding it read-write will almost certainly cause disk corruption, but adding it read-only is safe.

You must add at least one disk image, and you may add multiple disk images. In the API, the disk images are usually referred to as "/dev/sda" (for the first one you added), "/dev/sdb" (for the second one you added), etc.

Once ``guestfs_launch'' has been called you cannot add any more images. You can call ``guestfs_list_devices'' to get a list of the device names, in the order that you added them. See also ``BLOCK DEVICE NAMING'' below.

MOUNTING

Before you can read or write files, create directories and so on in a disk image that contains filesystems, you have to mount those filesystems using ``guestfs_mount''. If you already know that a disk image contains (for example) one partition with a filesystem on that partition, then you can mount it directly:

  guestfs_mount (g, "/dev/sda1", "/");
 
 

where "/dev/sda1" means literally the first partition (1) of the first disk image that we added ("/dev/sda"). If the disk contains Linux LVM2 logical volumes you could refer to those instead (eg. "/dev/VG/LV").

If you are given a disk image and you don't know what it contains then you have to find out. Libguestfs can do that too: use ``guestfs_list_partitions'' and ``guestfs_lvs'' to list possible partitions and LVs, and either try mounting each to see what is mountable, or else examine them with ``guestfs_vfs_type'' or ``guestfs_file''. Libguestfs also has a set of APIs for inspection of disk images (see ``INSPECTION'' below). But you might find it easier to look at higher level programs built on top of libguestfs, in particular virt-inspector(1).

To mount a disk image read-only, use ``guestfs_mount_ro''. There are several other variations of the "guestfs_mount_*" call.

FILESYSTEM ACCESS AND MODIFICATION

The majority of the libguestfs API consists of fairly low-level calls for accessing and modifying the files, directories, symlinks etc on mounted filesystems. There are over a hundred such calls which you can find listed in detail below in this man page, and we don't even pretend to cover them all in this overview.

Specify filenames as full paths, starting with "/" and including the mount point.

For example, if you mounted a filesystem at "/" and you want to read the file called "etc/passwd" then you could do:

  char *data = guestfs_cat (g, "/etc/passwd");
 
 

This would return "data" as a newly allocated buffer containing the full content of that file (with some conditions: see also ``DOWNLOADING'' below), or "NULL" if there was an error.

As another example, to create a top-level directory on that filesystem called "var" you would do:

  guestfs_mkdir (g, "/var");
 
 

To create a symlink you could do:

  guestfs_ln_s (g, "/etc/init.d/portmap",
                "/etc/rc3.d/S30portmap");
 
 

Libguestfs will reject attempts to use relative paths and there is no concept of a current working directory.

Libguestfs can return errors in many situations: for example if the filesystem isn't writable, or if a file or directory that you requested doesn't exist. If you are using the C API (documented here) you have to check for those error conditions after each call. (Other language bindings turn these errors into exceptions).

File writes are affected by the per-handle umask, set by calling ``guestfs_umask'' and defaulting to 022. See ``UMASK''.

PARTITIONING

Libguestfs contains API calls to read, create and modify partition tables on disk images.

In the common case where you want to create a single partition covering the whole disk, you should use the ``guestfs_part_disk'' call:

  const char *parttype = "mbr";
  if (disk_is_larger_than_2TB)
    parttype = "gpt";
  guestfs_part_disk (g, "/dev/sda", parttype);
 
 

Obviously this effectively wipes anything that was on that disk image before.

LVM2

Libguestfs provides access to a large part of the LVM2 API, such as ``guestfs_lvcreate'' and ``guestfs_vgremove''. It won't make much sense unless you familiarize yourself with the concepts of physical volumes, volume groups and logical volumes.

This author strongly recommends reading the LVM HOWTO, online at http://tldp.org/HOWTO/LVM-HOWTO/ <http://tldp.org/HOWTO/LVM-HOWTO/>.

DOWNLOADING

Use ``guestfs_cat'' to download small, text only files. This call is limited to files which are less than 2 MB and which cannot contain any ASCII NUL ("\0") characters. However it has a very simple to use API.

``guestfs_read_file'' can be used to read files which contain arbitrary 8 bit data, since it returns a (pointer, size) pair. However it is still limited to ``small'' files, less than 2 MB.

``guestfs_download'' can be used to download any file, with no limits on content or size (even files larger than 4 GB).

To download multiple files, see ``guestfs_tar_out'' and ``guestfs_tgz_out''.

UPLOADING

It's often the case that you want to write a file or files to the disk image.

To write a small file with fixed content, use ``guestfs_write''. To create a file of all zeroes, use ``guestfs_truncate_size'' (sparse) or ``guestfs_fallocate64'' (with all disk blocks allocated). There are a variety of other functions for creating test files, for example ``guestfs_fill'' and ``guestfs_fill_pattern''.

To upload a single file, use ``guestfs_upload''. This call has no limits on file content or size (even files larger than 4 GB).

To upload multiple files, see ``guestfs_tar_in'' and ``guestfs_tgz_in''.

However the fastest way to upload large numbers of arbitrary files is to turn them into a squashfs or CD ISO (see mksquashfs(8) and mkisofs(8)), then attach this using ``guestfs_add_drive_ro''. If you add the drive in a predictable way (eg. adding it last after all other drives) then you can get the device name from ``guestfs_list_devices'' and mount it directly using ``guestfs_mount_ro''. Note that squashfs images are sometimes non-portable between kernel versions, and they don't support labels or UUIDs. If you want to pre-build an image or you need to mount it using a label or UUID, use an ISO image instead.

COPYING

There are various different commands for copying between files and devices and in and out of the guest filesystem. These are summarised in the table below.

file to file

Use ``guestfs_cp'' to copy a single file, or ``guestfs_cp_a'' to copy directories recursively.

file or device to file or device

Use ``guestfs_dd'' which efficiently uses dd(1) to copy between files and devices in the guest.

Example: duplicate the contents of an LV:

  guestfs_dd (g, "/dev/VG/Original", "/dev/VG/Copy");
 
 

The destination ("/dev/VG/Copy") must be at least as large as the source ("/dev/VG/Original"). To copy less than the whole source device, use ``guestfs_copy_size''.

file on the host to file or device

Use ``guestfs_upload''. See ``UPLOADING'' above.

file or device to file on the host

Use ``guestfs_download''. See ``DOWNLOADING'' above.

LISTING FILES

``guestfs_ll'' is just designed for humans to read (mainly when using the guestfish(1)-equivalent command "ll").

``guestfs_ls'' is a quick way to get a list of files in a directory from programs, as a flat list of strings.

``guestfs_readdir'' is a programmatic way to get a list of files in a directory, plus additional information about each one. It is more equivalent to using the readdir(3) call on a local filesystem.

``guestfs_find'' and ``guestfs_find0'' can be used to recursively list files.

RUNNING COMMANDS

Although libguestfs is primarily an API for manipulating files inside guest images, we also provide some limited facilities for running commands inside guests.

There are many limitations to this:

*

The kernel version that the command runs under will be different from what it expects.

*

If the command needs to communicate with daemons, then most likely they won't be running.

*

The command will be running in limited memory.

*

The network may not be available unless you enable it (see ``guestfs_set_network'').

*

Only supports Linux guests (not Windows, BSD, etc).

*

Architecture limitations (eg. won't work for a PPC guest on an X86 host).

*

For SELinux guests, you may need to enable SELinux and load policy first. See ``SELINUX'' in this manpage.

The two main API calls to run commands are ``guestfs_command'' and ``guestfs_sh'' (there are also variations).

The difference is that ``guestfs_sh'' runs commands using the shell, so any shell globs, redirections, etc will work.

CONFIGURATION FILES

To read and write configuration files in Linux guest filesystems, we strongly recommend using Augeas. For example, Augeas understands how to read and write, say, a Linux shadow password file or X.org configuration file, and so avoids you having to write that code.

The main Augeas calls are bound through the "guestfs_aug_*" APIs. We don't document Augeas itself here because there is excellent documentation on the <http://augeas.net/> website.

If you don't want to use Augeas (you fool!) then try calling ``guestfs_read_lines'' to get the file as a list of lines which you can iterate over.

SELINUX

We support SELinux guests. To ensure that labeling happens correctly in SELinux guests, you need to enable SELinux and load the guest's policy:

1.

Before launching, do:

  guestfs_set_selinux (g, 1);
 
 

2.

After mounting the guest's filesystem(s), load the policy. This is best done by running the load_policy(8) command in the guest itself:

  guestfs_sh (g, "/usr/sbin/load_policy");
 
 

(Older versions of "load_policy" require you to specify the name of the policy file).

3.

Optionally, set the security context for the API. The correct security context to use can only be known by inspecting the guest. As an example:

  guestfs_setcon (g, "unconfined_u:unconfined_r:unconfined_t:s0");
 
 

This will work for running commands and editing existing files.

When new files are created, you may need to label them explicitly, for example by running the external command "restorecon pathname".

UMASK

Certain calls are affected by the current file mode creation mask (the ``umask''). In particular ones which create files or directories, such as ``guestfs_touch'', ``guestfs_mknod'' or ``guestfs_mkdir''. This affects either the default mode that the file is created with or modifies the mode that you supply.

The default umask is 022, so files are created with modes such as 0644 and directories with 0755.

There are two ways to avoid being affected by umask. Either set umask to 0 (call "guestfs_umask (g, 0)" early after launching). Or call ``guestfs_chmod'' after creating each file or directory.

For more information about umask, see umask(2).

ENCRYPTED DISKS

Libguestfs allows you to access Linux guests which have been encrypted using whole disk encryption that conforms to the Linux Unified Key Setup (LUKS) standard. This includes nearly all whole disk encryption systems used by modern Linux guests.

Use ``guestfs_vfs_type'' to identify LUKS-encrypted block devices (it returns the string "crypto_LUKS").

Then open these devices by calling ``guestfs_luks_open''. Obviously you will require the passphrase!

Opening a LUKS device creates a new device mapper device called "/dev/mapper/mapname" (where "mapname" is the string you supply to ``guestfs_luks_open''). Reads and writes to this mapper device are decrypted from and encrypted to the underlying block device respectively.

LVM volume groups on the device can be made visible by calling ``guestfs_vgscan'' followed by ``guestfs_vg_activate_all''. The logical volume(s) can now be mounted in the usual way.

Use the reverse process to close a LUKS device. Unmount any logical volumes on it, deactivate the volume groups by caling "guestfs_vg_activate (g, 0, ["/dev/VG"])". Then close the mapper device by calling ``guestfs_luks_close'' on the "/dev/mapper/mapname" device (not the underlying encrypted block device).

INSPECTION

Libguestfs has APIs for inspecting an unknown disk image to find out if it contains operating systems. (These APIs used to be in a separate Perl-only library called Sys::Guestfs::Lib(3) but since version 1.5.3 the most frequently used part of this library has been rewritten in C and moved into the core code).

Add all disks belonging to the unknown virtual machine and call ``guestfs_launch'' in the usual way.

Then call ``guestfs_inspect_os''. This function uses other libguestfs calls and certain heuristics, and returns a list of operating systems that were found. An empty list means none were found. A single element is the root filesystem of the operating system. For dual- or multi-boot guests, multiple roots can be returned, each one corresponding to a separate operating system. (Multi-boot virtual machines are extremely rare in the world of virtualization, but since this scenario can happen, we have built libguestfs to deal with it.)

For each root, you can then call various "guestfs_inspect_get_*" functions to get additional details about that operating system. For example, call ``guestfs_inspect_get_type'' to return the string "windows" or "linux" for Windows and Linux-based operating systems respectively.

Un*x-like and Linux-based operating systems usually consist of several filesystems which are mounted at boot time (for example, a separate boot partition mounted on "/boot"). The inspection rules are able to detect how filesystems correspond to mount points. Call "guestfs_inspect_get_mountpoints" to get this mapping. It might return a hash table like this example:

  /boot => /dev/sda1
  /     => /dev/vg_guest/lv_root
  /usr  => /dev/vg_guest/lv_usr
 
 

The caller can then make calls to ``guestfs_mount_options'' to mount the filesystems as suggested.

Be careful to mount filesystems in the right order (eg. "/" before "/usr"). Sorting the keys of the hash by length, shortest first, should work.

Inspection currently only works for some common operating systems. Contributors are welcome to send patches for other operating systems that we currently cannot detect.

Encrypted disks must be opened before inspection. See ``ENCRYPTED DISKS'' for more details. The ``guestfs_inspect_os'' function just ignores any encrypted devices.

A note on the implementation: The call ``guestfs_inspect_os'' performs inspection and caches the results in the guest handle. Subsequent calls to "guestfs_inspect_get_*" return this cached information, but do not re-read the disks. If you change the content of the guest disks, you can redo inspection by calling ``guestfs_inspect_os'' again.

SPECIAL CONSIDERATIONS FOR WINDOWS GUESTS

Libguestfs can mount NTFS partitions. It does this using the http://www.ntfs-3g.org/ <http://www.ntfs-3g.org/> driver.

DOS and Windows still use drive letters, and the filesystems are always treated as case insensitive by Windows itself, and therefore you might find a Windows configuration file referring to a path like "c:\windows\system32". When the filesystem is mounted in libguestfs, that directory might be referred to as "/WINDOWS/System32".

Drive letter mappings are outside the scope of libguestfs. You have to use libguestfs to read the appropriate Windows Registry and configuration files, to determine yourself how drives are mapped (see also hivex(3) and virt-inspector(1)).

Replacing backslash characters with forward slash characters is also outside the scope of libguestfs, but something that you can easily do.

Where we can help is in resolving the case insensitivity of paths. For this, call ``guestfs_case_sensitive_path''.

Libguestfs also provides some help for decoding Windows Registry ``hive'' files, through the library "hivex" which is part of the libguestfs project although ships as a separate tarball. You have to locate and download the hive file(s) yourself, and then pass them to "hivex" functions. See also the programs hivexml(1), hivexsh(1), hivexregedit(1) and virt-win-reg(1) for more help on this issue.

USING LIBGUESTFS WITH OTHER PROGRAMMING LANGUAGES

Although we don't want to discourage you from using the C API, we will mention here that the same API is also available in other languages.

The API is broadly identical in all supported languages. This means that the C call "guestfs_mount(g,path)" is "$g->mount($path)" in Perl, "g.mount(path)" in Python, and "Guestfs.mount g path" in OCaml. In other words, a straightforward, predictable isomorphism between each language.

Error messages are automatically transformed into exceptions if the language supports it.

We don't try to ``object orientify'' parts of the API in OO languages, although contributors are welcome to write higher level APIs above what we provide in their favourite languages if they wish.

C++

You can use the guestfs.h header file from C++ programs. The C++ API is identical to the C API. C++ classes and exceptions are not used.

C#

The C# bindings are highly experimental. Please read the warnings at the top of "csharp/Libguestfs.cs".

Haskell

This is the only language binding that is working but incomplete. Only calls which return simple integers have been bound in Haskell, and we are looking for help to complete this binding.

Java

Full documentation is contained in the Javadoc which is distributed with libguestfs.

OCaml

For documentation see the file "guestfs.mli".

Perl

For documentation see Sys::Guestfs(3).

PHP

For documentation see "README-PHP" supplied with libguestfs sources or in the php-libguestfs package for your distribution.

The PHP binding only works correctly on 64 bit machines.

Python

For documentation do:

  $ python
  >>> import guestfs
  >>> help (guestfs)
 
 

Ruby

Use the Guestfs module. There is no Ruby-specific documentation, but you can find examples written in Ruby in the libguestfs source.

shell scripts

For documentation see guestfish(1).

LIBGUESTFS GOTCHAS

<http://en.wikipedia.org/wiki/Gotcha_(programming)>: ``A feature of a system [...] that works in the way it is documented but is counterintuitive and almost invites mistakes.''

Since we developed libguestfs and the associated tools, there are several things we would have designed differently, but are now stuck with for backwards compatibility or other reasons. If there is ever a libguestfs 2.0 release, you can expect these to change. Beware of them.

Autosync / forgetting to sync.

When modifying a filesystem from C or another language, you must unmount all filesystems and call ``guestfs_sync'' explicitly before you close the libguestfs handle. You can also call:

  guestfs_set_autosync (g, 1);
 
 

to have the unmount/sync done automatically for you when the handle 'g' is closed. (This feature is called ``autosync'', ``guestfs_set_autosync'' q.v.)

If you forget to do this, then it is entirely possible that your changes won't be written out, or will be partially written, or (very rarely) that you'll get disk corruption.

Note that in guestfish(3) autosync is the default. So quick and dirty guestfish scripts that forget to sync will work just fine, which can make this very puzzling if you are trying to debug a problem.

Mount option -o sync should not be the default.

If you use ``guestfs_mount'', then "-o sync,noatime" are added implicitly. However "-o sync" does not add any reliability benefit, but does have a very large performance impact.

The work around is to use ``guestfs_mount_options'' and set the mount options that you actually want to use.

Read-only should be the default.

In guestfish(3), --ro should be the default, and you should have to specify --rw if you want to make changes to the image.

This would reduce the potential to corrupt live VM images.

Note that many filesystems change the disk when you just mount and unmount, even if you didn't perform any writes. You need to use ``guestfs_add_drive_ro'' to guarantee that the disk is not changed.

guestfish command line is hard to use.

"guestfish disk.img" doesn't do what people expect (open "disk.img" for examination). It tries to run a guestfish command "disk.img" which doesn't exist, so it fails. In earlier versions of guestfish the error message was also unintuitive, but we have corrected this since. Like the Bourne shell, we should have used "guestfish -c command" to run commands.

guestfish megabyte modifiers don't work right on all commands

In recent guestfish you can use "1M" to mean 1 megabyte (and similarly for other modifiers). What guestfish actually does is to multiply the number part by the modifier part and pass the result to the C API. However this doesn't work for a few APIs which aren't expecting bytes, but are already expecting some other unit (eg. megabytes).

The most common is ``guestfs_lvcreate''. The guestfish command:

  lvcreate LV VG 100M
 
 

does not do what you might expect. Instead because ``guestfs_lvcreate'' is already expecting megabytes, this tries to create a 100 terabyte (100 megabytes * megabytes) logical volume. The error message you get from this is also a little obscure.

This could be fixed in the generator by specially marking parameters and return values which take bytes or other units.

Library should return errno with error messages.

It would be a nice-to-have to be able to get the original value of 'errno' from inside the appliance along error paths (where set). Currently guestmount(1) goes through hoops to try to reverse the error message string into an errno, see the function error() in fuse/guestmount.c.

In libguestfs 1.5.4, the protocol was changed so that the Linux errno is sent back from the daemon.

Ambiguity between devices and paths

There is a subtle ambiguity in the API between a device name (eg. "/dev/sdb2") and a similar pathname. A file might just happen to be called "sdb2" in the directory "/dev" (consider some non-Unix VM image).

In the current API we usually resolve this ambiguity by having two separate calls, for example ``guestfs_checksum'' and ``guestfs_checksum_device''. Some API calls are ambiguous and (incorrectly) resolve the problem by detecting if the path supplied begins with "/dev/".

To avoid both the ambiguity and the need to duplicate some calls, we could make paths/devices into structured names. One way to do this would be to use a notation like grub ("hd(0,0)"), although nobody really likes this aspect of grub. Another way would be to use a structured type, equivalent to this OCaml type:

  type path = Path of string | Device of int | Partition of int * int
 
 

which would allow you to pass arguments like:

  Path "/foo/bar"
  Device 1            (* /dev/sdb, or perhaps /dev/sda *)
  Partition (1, 2)    (* /dev/sdb2 (or is it /dev/sda2 or /dev/sdb3?) *)
  Path "/dev/sdb2"    (* not a device *)
 
 

As you can see there are still problems to resolve even with this representation. Also consider how it might work in guestfish.

PROTOCOL LIMITS

Internally libguestfs uses a message-based protocol to pass API calls and their responses to and from a small ``appliance'' (see ``INTERNALS'' for plenty more detail about this). The maximum message size used by the protocol is slightly less than 4 MB. For some API calls you may need to be aware of this limit. The API calls which may be affected are individually documented, with a link back to this section of the documentation.

A simple call such as ``guestfs_cat'' returns its result (the file data) in a simple string. Because this string is at some point internally encoded as a message, the maximum size that it can return is slightly under 4 MB. If the requested file is larger than this then you will get an error.

In order to transfer large files into and out of the guest filesystem, you need to use particular calls that support this. The sections ``UPLOADING'' and ``DOWNLOADING'' document how to do this.

You might also consider mounting the disk image using our FUSE filesystem support (guestmount(1)).

KEYS AND PASSPHRASES

Certain libguestfs calls take a parameter that contains sensitive key material, passed in as a C string.

In the future we would hope to change the libguestfs implementation so that keys are mlock(2)-ed into physical RAM, and thus can never end up in swap. However this is not done at the moment, because of the complexity of such an implementation.

Therefore you should be aware that any key parameter you pass to libguestfs might end up being written out to the swap partition. If this is a concern, scrub the swap partition or don't use libguestfs on encrypted devices.

CONNECTION MANAGEMENT

guestfs_h *

"guestfs_h" is the opaque type representing a connection handle. Create a handle by calling ``guestfs_create''. Call ``guestfs_close'' to free the handle and release all resources used.

For information on using multiple handles and threads, see the section ``MULTIPLE HANDLES AND MULTIPLE THREADS'' below.

guestfs_create

  guestfs_h *guestfs_create (void);
 
 

Create a connection handle.

You have to call ``guestfs_add_drive'' on the handle at least once.

This function returns a non-NULL pointer to a handle on success or NULL on error.

After configuring the handle, you have to call ``guestfs_launch''.

You may also want to configure error handling for the handle. See ``ERROR HANDLING'' section below.

guestfs_close

  void guestfs_close (guestfs_h *g);
 
 

This closes the connection handle and frees up all resources used.

ERROR HANDLING

The convention in all functions that return "int" is that they return "-1" to indicate an error. You can get additional information on errors by calling ``guestfs_last_error'' and/or by setting up an error handler with ``guestfs_set_error_handler''.

The default error handler prints the information string to "stderr".

Out of memory errors are handled differently. The default action is to call abort(3). If this is undesirable, then you can set a handler using ``guestfs_set_out_of_memory_handler''.

guestfs_last_error

  const char *guestfs_last_error (guestfs_h *g);
 
 

This returns the last error message that happened on "g". If there has not been an error since the handle was created, then this returns "NULL".

The lifetime of the returned string is until the next error occurs, or ``guestfs_close'' is called.

The error string is not localized (ie. is always in English), because this makes searching for error messages in search engines give the largest number of results.

guestfs_set_error_handler

  typedef void (*guestfs_error_handler_cb) (guestfs_h *g,
                                            void *opaque,
                                            const char *msg);
  void guestfs_set_error_handler (guestfs_h *g,
                                  guestfs_error_handler_cb cb,
                                  void *opaque);
 
 

The callback "cb" will be called if there is an error. The parameters passed to the callback are an opaque data pointer and the error message string.

Note that the message string "msg" is freed as soon as the callback function returns, so if you want to stash it somewhere you must make your own copy.

The default handler prints messages on "stderr".

If you set "cb" to "NULL" then no handler is called.

guestfs_get_error_handler

  guestfs_error_handler_cb guestfs_get_error_handler (guestfs_h *g,
                                                      void **opaque_rtn);
 
 

Returns the current error handler callback.

guestfs_set_out_of_memory_handler

  typedef void (*guestfs_abort_cb) (void);
  int guestfs_set_out_of_memory_handler (guestfs_h *g,
                                         guestfs_abort_cb);
 
 

The callback "cb" will be called if there is an out of memory situation. Note this callback must not return.

The default is to call abort(3).

You cannot set "cb" to "NULL". You can't ignore out of memory situations.

guestfs_get_out_of_memory_handler

  guestfs_abort_fn guestfs_get_out_of_memory_handler (guestfs_h *g);
 
 

This returns the current out of memory handler.

PATH

Libguestfs needs a kernel and initrd.img, which it finds by looking along an internal path.

By default it looks for these in the directory "$libdir/guestfs" (eg. "/usr/local/lib/guestfs" or "/usr/lib64/guestfs").

Use ``guestfs_set_path'' or set the environment variable ``LIBGUESTFS_PATH'' to change the directories that libguestfs will search in. The value is a colon-separated list of paths. The current directory is not searched unless the path contains an empty element or ".". For example "LIBGUESTFS_PATH=:/usr/lib/guestfs" would search the current directory and then "/usr/lib/guestfs".

HIGH-LEVEL API ACTIONS

ABI GUARANTEE

We guarantee the libguestfs ABI (binary interface), for public, high-level actions as outlined in this section. Although we will deprecate some actions, for example if they get replaced by newer calls, we will keep the old actions forever. This allows you the developer to program in confidence against the libguestfs API.

guestfs_add_cdrom

  int guestfs_add_cdrom (guestfs_h *g,
                 const char *filename);
 
 

This function adds a virtual CD-ROM disk image to the guest.

This is equivalent to the qemu parameter "-cdrom filename".

Notes:

*

This call checks for the existence of "filename". This stops you from specifying other types of drive which are supported by qemu such as "nbd:" and "http:" URLs. To specify those, use the general "guestfs_config" call instead.

*

If you just want to add an ISO file (often you use this as an efficient way to transfer large files into the guest), then you should probably use "guestfs_add_drive_ro" instead.

This function returns 0 on success or -1 on error.

guestfs_add_drive

  int guestfs_add_drive (guestfs_h *g,
                 const char *filename);
 
 

This function adds a virtual machine disk image "filename" to the guest. The first time you call this function, the disk appears as IDE disk 0 ("/dev/sda") in the guest, the second time as "/dev/sdb", and so on.

You don't necessarily need to be root when using libguestfs. However you obviously do need sufficient permissions to access the filename for whatever operations you want to perform (ie. read access if you just want to read the image or write access if you want to modify the image).

This is equivalent to the qemu parameter "-drive file=filename,cache=off,if=...".

"cache=off" is omitted in cases where it is not supported by the underlying filesystem.

"if=..." is set at compile time by the configuration option "./configure --with-drive-if=...". In the rare case where you might need to change this at run time, use "guestfs_add_drive_with_if" or "guestfs_add_drive_ro_with_if".

Note that this call checks for the existence of "filename". This stops you from specifying other types of drive which are supported by qemu such as "nbd:" and "http:" URLs. To specify those, use the general "guestfs_config" call instead.

This function returns 0 on success or -1 on error.

guestfs_add_drive_ro

  int guestfs_add_drive_ro (guestfs_h *g,
                 const char *filename);
 
 

This adds a drive in snapshot mode, making it effectively read-only.

Note that writes to the device are allowed, and will be seen for the duration of the guestfs handle, but they are written to a temporary file which is discarded as soon as the guestfs handle is closed. We don't currently have any method to enable changes to be committed, although qemu can support this.

This is equivalent to the qemu parameter "-drive file=filename,snapshot=on,if=...".

"if=..." is set at compile time by the configuration option "./configure --with-drive-if=...". In the rare case where you might need to change this at run time, use "guestfs_add_drive_with_if" or "guestfs_add_drive_ro_with_if".

Note that this call checks for the existence of "filename". This stops you from specifying other types of drive which are supported by qemu such as "nbd:" and "http:" URLs. To specify those, use the general "guestfs_config" call instead.

This function returns 0 on success or -1 on error.

guestfs_add_drive_ro_with_if

  int guestfs_add_drive_ro_with_if (guestfs_h *g,
                 const char *filename,
                 const char *iface);
 
 

This is the same as "guestfs_add_drive_ro" but it allows you to specify the QEMU interface emulation to use at run time.

This function returns 0 on success or -1 on error.

guestfs_add_drive_with_if

  int guestfs_add_drive_with_if (guestfs_h *g,
                 const char *filename,
                 const char *iface);
 
 

This is the same as "guestfs_add_drive" but it allows you to specify the QEMU interface emulation to use at run time.

This function returns 0 on success or -1 on error.

guestfs_aug_clear

  int guestfs_aug_clear (guestfs_h *g,
                 const char *augpath);
 
 

Set the value associated with "path" to "NULL". This is the same as the augtool(1) "clear" command.

This function returns 0 on success or -1 on error.

guestfs_aug_close

  int guestfs_aug_close (guestfs_h *g);
 
 

Close the current Augeas handle and free up any resources used by it. After calling this, you have to call "guestfs_aug_init" again before you can use any other Augeas functions.

This function returns 0 on success or -1 on error.

guestfs_aug_defnode

  struct guestfs_int_bool *guestfs_aug_defnode (guestfs_h *g,
                 const char *name,
                 const char *expr,
                 const char *val);
 
 

Defines a variable "name" whose value is the result of evaluating "expr".

If "expr" evaluates to an empty nodeset, a node is created, equivalent to calling "guestfs_aug_set" "expr", "value". "name" will be the nodeset containing that single node.

On success this returns a pair containing the number of nodes in the nodeset, and a boolean flag if a node was created.

This function returns a "struct guestfs_int_bool *", or NULL if there was an error. The caller must call "guestfs_free_int_bool" after use.

guestfs_aug_defvar

  int guestfs_aug_defvar (guestfs_h *g,
                 const char *name,
                 const char *expr);
 
 

Defines an Augeas variable "name" whose value is the result of evaluating "expr". If "expr" is NULL, then "name" is undefined.

On success this returns the number of nodes in "expr", or 0 if "expr" evaluates to something which is not a nodeset.

On error this function returns -1.

guestfs_aug_get

  char *guestfs_aug_get (guestfs_h *g,
                 const char *augpath);
 
 

Look up the value associated with "path". If "path" matches exactly one node, the "value" is returned.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_aug_init

  int guestfs_aug_init (guestfs_h *g,
                 const char *root,
                 int flags);
 
 

Create a new Augeas handle for editing configuration files. If there was any previous Augeas handle associated with this guestfs session, then it is closed.

You must call this before using any other "guestfs_aug_*" commands.

"root" is the filesystem root. "root" must not be NULL, use "/" instead.

The flags are the same as the flags defined in <augeas.h>, the logical or of the following integers:

AUG_SAVE_BACKUP = 1

Keep the original file with a ".augsave" extension.

AUG_SAVE_NEWFILE = 2

Save changes into a file with extension ".augnew", and do not overwrite original. Overrides "AUG_SAVE_BACKUP".

AUG_TYPE_CHECK = 4

Typecheck lenses (can be expensive).

AUG_NO_STDINC = 8

Do not use standard load path for modules.

AUG_SAVE_NOOP = 16

Make save a no-op, just record what would have been changed.

AUG_NO_LOAD = 32

Do not load the tree in "guestfs_aug_init".

To close the handle, you can call "guestfs_aug_close".

To find out more about Augeas, see <http://augeas.net/>.

This function returns 0 on success or -1 on error.

guestfs_aug_insert

  int guestfs_aug_insert (guestfs_h *g,
                 const char *augpath,
                 const char *label,
                 int before);
 
 

Create a new sibling "label" for "path", inserting it into the tree before or after "path" (depending on the boolean flag "before").

"path" must match exactly one existing node in the tree, and "label" must be a label, ie. not contain "/", "*" or end with a bracketed index "[N]".

This function returns 0 on success or -1 on error.

guestfs_aug_load

  int guestfs_aug_load (guestfs_h *g);
 
 

Load files into the tree.

See "aug_load" in the Augeas documentation for the full gory details.

This function returns 0 on success or -1 on error.

guestfs_aug_ls

  char **guestfs_aug_ls (guestfs_h *g,
                 const char *augpath);
 
 

This is just a shortcut for listing "guestfs_aug_match" "path/*" and sorting the resulting nodes into alphabetical order.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_aug_match

  char **guestfs_aug_match (guestfs_h *g,
                 const char *augpath);
 
 

Returns a list of paths which match the path expression "path". The returned paths are sufficiently qualified so that they match exactly one node in the current tree.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_aug_mv

  int guestfs_aug_mv (guestfs_h *g,
                 const char *src,
                 const char *dest);
 
 

Move the node "src" to "dest". "src" must match exactly one node. "dest" is overwritten if it exists.

This function returns 0 on success or -1 on error.

guestfs_aug_rm

  int guestfs_aug_rm (guestfs_h *g,
                 const char *augpath);
 
 

Remove "path" and all of its children.

On success this returns the number of entries which were removed.

On error this function returns -1.

guestfs_aug_save

  int guestfs_aug_save (guestfs_h *g);
 
 

This writes all pending changes to disk.

The flags which were passed to "guestfs_aug_init" affect exactly how files are saved.

This function returns 0 on success or -1 on error.

guestfs_aug_set

  int guestfs_aug_set (guestfs_h *g,
                 const char *augpath,
                 const char *val);
 
 

Set the value associated with "path" to "val".

In the Augeas API, it is possible to clear a node by setting the value to NULL. Due to an oversight in the libguestfs API you cannot do that with this call. Instead you must use the "guestfs_aug_clear" call.

This function returns 0 on success or -1 on error.

guestfs_available

  int guestfs_available (guestfs_h *g,
                 char *const *groups);
 
 

This command is used to check the availability of some groups of functionality in the appliance, which not all builds of the libguestfs appliance will be able to provide.

The libguestfs groups, and the functions that those groups correspond to, are listed in ``AVAILABILITY'' in guestfs(3). You can also fetch this list at runtime by calling "guestfs_available_all_groups".

The argument "groups" is a list of group names, eg: "["inotify", "augeas"]" would check for the availability of the Linux inotify functions and Augeas (configuration file editing) functions.

The command returns no error if all requested groups are available.

It fails with an error if one or more of the requested groups is unavailable in the appliance.

If an unknown group name is included in the list of groups then an error is always returned.

Notes:

*

You must call "guestfs_launch" before calling this function.

The reason is because we don't know what groups are supported by the appliance/daemon until it is running and can be queried.

*

If a group of functions is available, this does not necessarily mean that they will work. You still have to check for errors when calling individual API functions even if they are available.

*

It is usually the job of distro packagers to build complete functionality into the libguestfs appliance. Upstream libguestfs, if built from source with all requirements satisfied, will support everything.

*

This call was added in version 1.0.80. In previous versions of libguestfs all you could do would be to speculatively execute a command to find out if the daemon implemented it. See also "guestfs_version".

This function returns 0 on success or -1 on error.

guestfs_available_all_groups

  char **guestfs_available_all_groups (guestfs_h *g);
 
 

This command returns a list of all optional groups that this daemon knows about. Note this returns both supported and unsupported groups. To find out which ones the daemon can actually support you have to call "guestfs_available" on each member of the returned list.

See also "guestfs_available" and ``AVAILABILITY'' in guestfs(3).

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_base64_in

  int guestfs_base64_in (guestfs_h *g,
                 const char *base64file,
                 const char *filename);
 
 

This command uploads base64-encoded data from "base64file" to "filename".

This function returns 0 on success or -1 on error.

guestfs_base64_out

  int guestfs_base64_out (guestfs_h *g,
                 const char *filename,
                 const char *base64file);
 
 

This command downloads the contents of "filename", writing it out to local file "base64file" encoded as base64.

This function returns 0 on success or -1 on error.

guestfs_blockdev_flushbufs

  int guestfs_blockdev_flushbufs (guestfs_h *g,
                 const char *device);
 
 

This tells the kernel to flush internal buffers associated with "device".

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

guestfs_blockdev_getbsz

  int guestfs_blockdev_getbsz (guestfs_h *g,
                 const char *device);
 
 

This returns the block size of a device.

(Note this is different from both size in blocks and filesystem block size).

This uses the blockdev(8) command.

On error this function returns -1.

guestfs_blockdev_getro

  int guestfs_blockdev_getro (guestfs_h *g,
                 const char *device);
 
 

Returns a boolean indicating if the block device is read-only (true if read-only, false if not).

This uses the blockdev(8) command.

This function returns a C truth value on success or -1 on error.

guestfs_blockdev_getsize64

  int64_t guestfs_blockdev_getsize64 (guestfs_h *g,
                 const char *device);
 
 

This returns the size of the device in bytes.

See also "guestfs_blockdev_getsz".

This uses the blockdev(8) command.

On error this function returns -1.

guestfs_blockdev_getss

  int guestfs_blockdev_getss (guestfs_h *g,
                 const char *device);
 
 

This returns the size of sectors on a block device. Usually 512, but can be larger for modern devices.

(Note, this is not the size in sectors, use "guestfs_blockdev_getsz" for that).

This uses the blockdev(8) command.

On error this function returns -1.

guestfs_blockdev_getsz

  int64_t guestfs_blockdev_getsz (guestfs_h *g,
                 const char *device);
 
 

This returns the size of the device in units of 512-byte sectors (even if the sectorsize isn't 512 bytes ... weird).

See also "guestfs_blockdev_getss" for the real sector size of the device, and "guestfs_blockdev_getsize64" for the more useful size in bytes.

This uses the blockdev(8) command.

On error this function returns -1.

guestfs_blockdev_rereadpt

  int guestfs_blockdev_rereadpt (guestfs_h *g,
                 const char *device);
 
 

Reread the partition table on "device".

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

guestfs_blockdev_setbsz

  int guestfs_blockdev_setbsz (guestfs_h *g,
                 const char *device,
                 int blocksize);
 
 

This sets the block size of a device.

(Note this is different from both size in blocks and filesystem block size).

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

guestfs_blockdev_setro

  int guestfs_blockdev_setro (guestfs_h *g,
                 const char *device);
 
 

Sets the block device named "device" to read-only.

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

guestfs_blockdev_setrw

  int guestfs_blockdev_setrw (guestfs_h *g,
                 const char *device);
 
 

Sets the block device named "device" to read-write.

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

guestfs_case_sensitive_path

  char *guestfs_case_sensitive_path (guestfs_h *g,
                 const char *path);
 
 

This can be used to resolve case insensitive paths on a filesystem which is case sensitive. The use case is to resolve paths which you have read from Windows configuration files or the Windows Registry, to the true path.

The command handles a peculiarity of the Linux ntfs-3g filesystem driver (and probably others), which is that although the underlying filesystem is case-insensitive, the driver exports the filesystem to Linux as case-sensitive.

One consequence of this is that special directories such as "c:\windows" may appear as "/WINDOWS" or "/windows" (or other things) depending on the precise details of how they were created. In Windows itself this would not be a problem.

Bug or feature? You decide: http://www.tuxera.com/community/ntfs-3g-faq/#posixfilenames1 <http://www.tuxera.com/community/ntfs-3g-faq/#posixfilenames1>

This function resolves the true case of each element in the path and returns the case-sensitive path.

Thus "guestfs_case_sensitive_path" (``/Windows/System32'') might return "/WINDOWS/system32" (the exact return value would depend on details of how the directories were originally created under Windows).

Note: This function does not handle drive names, backslashes etc.

See also "guestfs_realpath".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_cat

  char *guestfs_cat (guestfs_h *g,
                 const char *path);
 
 

Return the contents of the file named "path".

Note that this function cannot correctly handle binary files (specifically, files containing "\0" character which is treated as end of string). For those you need to use the "guestfs_read_file" or "guestfs_download" functions which have a more complex interface.

This function returns a string, or NULL on error. The caller must free the returned string after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_checksum

  char *guestfs_checksum (guestfs_h *g,
                 const char *csumtype,
                 const char *path);
 
 

This call computes the MD5, SHAx or CRC checksum of the file named "path".

The type of checksum to compute is given by the "csumtype" parameter which must have one of the following values:

crc

Compute the cyclic redundancy check (CRC) specified by POSIX for the "cksum" command.

md5

Compute the MD5 hash (using the "md5sum" program).

sha1

Compute the SHA1 hash (using the "sha1sum" program).

sha224

Compute the SHA224 hash (using the "sha224sum" program).

sha256

Compute the SHA256 hash (using the "sha256sum" program).

sha384

Compute the SHA384 hash (using the "sha384sum" program).

sha512

Compute the SHA512 hash (using the "sha512sum" program).

The checksum is returned as a printable string.

To get the checksum for a device, use "guestfs_checksum_device".

To get the checksums for many files, use "guestfs_checksums_out".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_checksum_device

  char *guestfs_checksum_device (guestfs_h *g,
                 const char *csumtype,
                 const char *device);
 
 

This call computes the MD5, SHAx or CRC checksum of the contents of the device named "device". For the types of checksums supported see the "guestfs_checksum" command.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_checksums_out

  int guestfs_checksums_out (guestfs_h *g,
                 const char *csumtype,
                 const char *directory,
                 const char *sumsfile);
 
 

This command computes the checksums of all regular files in "directory" and then emits a list of those checksums to the local output file "sumsfile".

This can be used for verifying the integrity of a virtual machine. However to be properly secure you should pay attention to the output of the checksum command (it uses the ones from GNU coreutils). In particular when the filename is not printable, coreutils uses a special backslash syntax. For more information, see the GNU coreutils info file.

This function returns 0 on success or -1 on error.

guestfs_chmod

  int guestfs_chmod (guestfs_h *g,
                 int mode,
                 const char *path);
 
 

Change the mode (permissions) of "path" to "mode". Only numeric modes are supported.

Note: When using this command from guestfish, "mode" by default would be decimal, unless you prefix it with 0 to get octal, ie. use 0700 not 700.

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

guestfs_chown

  int guestfs_chown (guestfs_h *g,
                 int owner,
                 int group,
                 const char *path);
 
 

Change the file owner to "owner" and group to "group".

Only numeric uid and gid are supported. If you want to use names, you will need to locate and parse the password file yourself (Augeas support makes this relatively easy).

This function returns 0 on success or -1 on error.

guestfs_command

  char *guestfs_command (guestfs_h *g,
                 char *const *arguments);
 
 

This call runs a command from the guest filesystem. The filesystem must be mounted, and must contain a compatible operating system (ie. something Linux, with the same or compatible processor architecture).

The single parameter is an argv-style list of arguments. The first element is the name of the program to run. Subsequent elements are parameters. The list must be non-empty (ie. must contain a program name). Note that the command runs directly, and is not invoked via the shell (see "guestfs_sh").

The return value is anything printed to stdout by the command.

If the command returns a non-zero exit status, then this function returns an error message. The error message string is the content of stderr from the command.

The $PATH environment variable will contain at least "/usr/bin" and "/bin". If you require a program from another location, you should provide the full path in the first parameter.

Shared libraries and data files required by the program must be available on filesystems which are mounted in the correct places. It is the caller's responsibility to ensure all filesystems that are needed are mounted at the right locations.

This function returns a string, or NULL on error. The caller must free the returned string after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_command_lines

  char **guestfs_command_lines (guestfs_h *g,
                 char *const *arguments);
 
 

This is the same as "guestfs_command", but splits the result into a list of lines.

See also: "guestfs_sh_lines"

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_config

  int guestfs_config (guestfs_h *g,
                 const char *qemuparam,
                 const char *qemuvalue);
 
 

This can be used to add arbitrary qemu command line parameters of the form "-param value". Actually it's not quite arbitrary - we prevent you from setting some parameters which would interfere with parameters that we use.

The first character of "param" string must be a "-" (dash).

"value" can be NULL.

This function returns 0 on success or -1 on error.

guestfs_copy_size

  int guestfs_copy_size (guestfs_h *g,
                 const char *src,
                 const char *dest,
                 int64_t size);
 
 

This command copies exactly "size" bytes from one source device or file "src" to another destination device or file "dest".

Note this will fail if the source is too short or if the destination is not large enough.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress callback. See ``guestfs_set_progress_callback'' in guestfs(3).

guestfs_cp

  int guestfs_cp (guestfs_h *g,
                 const char *src,
                 const char *dest);
 
 

This copies a file from "src" to "dest" where "dest" is either a destination filename or destination directory.

This function returns 0 on success or -1 on error.

guestfs_cp_a

  int guestfs_cp_a (guestfs_h *g,
                 const char *src,
                 const char *dest);
 
 

This copies a file or directory from "src" to "dest" recursively using the "cp -a" command.

This function returns 0 on success or -1 on error.

guestfs_dd

  int guestfs_dd (guestfs_h *g,
                 const char *src,
                 const char *dest);
 
 

This command copies from one source device or file "src" to another destination device or file "dest". Normally you would use this to copy to or from a device or partition, for example to duplicate a filesystem.

If the destination is a device, it must be as large or larger than the source file or device, otherwise the copy will fail. This command cannot do partial copies (see "guestfs_copy_size").

This function returns 0 on success or -1 on error.

guestfs_debug

  char *guestfs_debug (guestfs_h *g,
                 const char *subcmd,
                 char *const *extraargs);
 
 

The "guestfs_debug" command exposes some internals of "guestfsd" (the guestfs daemon) that runs inside the qemu subprocess.

There is no comprehensive help for this command. You have to look at the file "daemon/debug.c" in the libguestfs source to find out what you can do.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_debug_upload

  int guestfs_debug_upload (guestfs_h *g,
                 const char *filename,
                 const char *tmpname,
                 int mode);
 
 

The "guestfs_debug_upload" command uploads a file to the libguestfs appliance.

There is no comprehensive help for this command. You have to look at the file "daemon/debug.c" in the libguestfs source to find out what it is for.

This function returns 0 on success or -1 on error.

guestfs_df

  char *guestfs_df (guestfs_h *g);
 
 

This command runs the "df" command to report disk space used.

This command is mostly useful for interactive sessions. It is not intended that you try to parse the output string. Use "statvfs" from programs.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_df_h

  char *guestfs_df_h (guestfs_h *g);
 
 

This command runs the "df -h" command to report disk space used in human-readable format.

This command is mostly useful for interactive sessions. It is not intended that you try to parse the output string. Use "statvfs" from programs.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_dmesg

  char *guestfs_dmesg (guestfs_h *g);
 
 

This returns the kernel messages ("dmesg" output) from the guest kernel. This is sometimes useful for extended debugging of problems.

Another way to get the same information is to enable verbose messages with "guestfs_set_verbose" or by setting the environment variable "LIBGUESTFS_DEBUG=1" before running the program.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_download

  int guestfs_download (guestfs_h *g,
                 const char *remotefilename,
                 const char *filename);
 
 

Download file "remotefilename" and save it as "filename" on the local machine.

"filename" can also be a named pipe.

See also "guestfs_upload", "guestfs_cat".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress callback. See ``guestfs_set_progress_callback'' in guestfs(3).

guestfs_download_offset

  int guestfs_download_offset (guestfs_h *g,
                 const char *remotefilename,
                 const char *filename,
                 int64_t offset,
                 int64_t size);
 
 

Download file "remotefilename" and save it as "filename" on the local machine.

"remotefilename" is read for "size" bytes starting at "offset" (this region must be within the file or device).

Note that there is no limit on the amount of data that can be downloaded with this call, unlike with "guestfs_pread", and this call always reads the full amount unless an error occurs.

See also "guestfs_download", "guestfs_pread".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress callback. See ``guestfs_set_progress_callback'' in guestfs(3).

guestfs_drop_caches

  int guestfs_drop_caches (guestfs_h *g,
                 int whattodrop);
 
 

This instructs the guest kernel to drop its page cache, and/or dentries and inode caches. The parameter "whattodrop" tells the kernel what precisely to drop, see http://linux-mm.org/Drop_Caches <http://linux-mm.org/Drop_Caches>

Setting "whattodrop" to 3 should drop everything.

This automatically calls sync(2) before the operation, so that the maximum guest memory is freed.

This function returns 0 on success or -1 on error.

guestfs_du

  int64_t guestfs_du (guestfs_h *g,
                 const char *path);
 
 

This command runs the "du -s" command to estimate file space usage for "path".

"path" can be a file or a directory. If "path" is a directory then the estimate includes the contents of the directory and all subdirectories (recursively).

The result is the estimated size in kilobytes (ie. units of 1024 bytes).

On error this function returns -1.

guestfs_e2fsck_f

  int guestfs_e2fsck_f (guestfs_h *g,
                 const char *device);
 
 

This runs "e2fsck -p -f device", ie. runs the ext2/ext3 filesystem checker on "device", noninteractively ("-p"), even if the filesystem appears to be clean ("-f").

This command is only needed because of "guestfs_resize2fs" (q.v.). Normally you should use "guestfs_fsck".

This function returns 0 on success or -1 on error.

guestfs_echo_daemon

  char *guestfs_echo_daemon (guestfs_h *g,
                 char *const *words);
 
 

This command concatenates the list of "words" passed with single spaces between them and returns the resulting string.

You can use this command to test the connection through to the daemon.

See also "guestfs_ping_daemon".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_egrep

  char **guestfs_egrep (guestfs_h *g,
                 const char *regex,
                 const char *path);
 
 

This calls the external "egrep" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_egrepi

  char **guestfs_egrepi (guestfs_h *g,
                 const char *regex,
                 const char *path);
 
 

This calls the external "egrep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_equal

  int guestfs_equal (guestfs_h *g,
                 const char *file1,
                 const char *file2);
 
 

This compares the two files "file1" and "file2" and returns true if their content is exactly equal, or false otherwise.

The external cmp(1) program is used for the comparison.

This function returns a C truth value on success or -1 on error.

guestfs_exists

  int guestfs_exists (guestfs_h *g,
                 const char *path);
 
 

This returns "true" if and only if there is a file, directory (or anything) with the given "path" name.

See also "guestfs_is_file", "guestfs_is_dir", "guestfs_stat".

This function returns a C truth value on success or -1 on error.

guestfs_fallocate

  int guestfs_fallocate (guestfs_h *g,
                 const char *path,
                 int len);
 
 

This command preallocates a file (containing zero bytes) named "path" of size "len" bytes. If the file exists already, it is overwritten.

Do not confuse this with the guestfish-specific "alloc" command which allocates a file in the host and attaches it as a device.

This function returns 0 on success or -1 on error.

This function is deprecated. In new code, use the "fallocate64" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

guestfs_fallocate64

  int guestfs_fallocate64 (guestfs_h *g,
                 const char *path,
                 int64_t len);
 
 

This command preallocates a file (containing zero bytes) named "path" of size "len" bytes. If the file exists already, it is overwritten.

Note that this call allocates disk blocks for the file. To create a sparse file use "guestfs_truncate_size" instead.

The deprecated call "guestfs_fallocate" does the same, but owing to an oversight it only allowed 30 bit lengths to be specified, effectively limiting the maximum size of files created through that call to 1GB.

Do not confuse this with the guestfish-specific "alloc" and "sparse" commands which create a file in the host and attach it as a device.

This function returns 0 on success or -1 on error.

guestfs_fgrep

  char **guestfs_fgrep (guestfs_h *g,
                 const char *pattern,
                 const char *path);
 
 

This calls the external "fgrep" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_fgrepi

  char **guestfs_fgrepi (guestfs_h *g,
                 const char *pattern,
                 const char *path);
 
 

This calls the external "fgrep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_file

  char *guestfs_file (guestfs_h *g,
                 const char *path);
 
 

This call uses the standard file(1) command to determine the type or contents of the file.

This call will also transparently look inside various types of compressed file.

The exact command which runs is "file -zb path". Note in particular that the filename is not prepended to the output (the "-b" option).

This command can also be used on "/dev/" devices (and partitions, LV names). You can for example use this to determine if a device contains a filesystem, although it's usually better to use "guestfs_vfs_type".

If the "path" does not begin with "/dev/" then this command only works for the content of regular files. For other file types (directory, symbolic link etc) it will just return the string "directory" etc.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_file_architecture

  char *guestfs_file_architecture (guestfs_h *g,
                 const char *filename);
 
 

This detects the architecture of the binary "filename", and returns it if known.

Currently defined architectures are:

i386

This string is returned for all 32 bit i386, i486, i586, i686 binaries irrespective of the precise processor requirements of the binary.

x86_64

64 bit x86-64.

sparc

32 bit SPARC.

sparc64

64 bit SPARC V9 and above.

ia64

Intel Itanium.

ppc

32 bit Power PC.

ppc64

64 bit Power PC.

Libguestfs may return other architecture strings in future.

The function works on at least the following types of files:

*

many types of Un*x and Linux binary

*

many types of Un*x and Linux shared library

*

Windows Win32 and Win64 binaries

*

Windows Win32 and Win64 DLLs

Win32 binaries and DLLs return "i386".

Win64 binaries and DLLs return "x86_64".

*

Linux kernel modules

*

Linux new-style initrd images

*

some non-x86 Linux vmlinuz kernels

What it can't do currently:

*

static libraries (libfoo.a)

*

Linux old-style initrd as compressed ext2 filesystem (RHEL 3)

*

x86 Linux vmlinuz kernels

x86 vmlinuz images (bzImage format) consist of a mix of 16-, 32- and compressed code, and are horribly hard to unpack. If you want to find the architecture of a kernel, use the architecture of the associated initrd or kernel module(s) instead.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_filesize

  int64_t guestfs_filesize (guestfs_h *g,
                 const char *file);
 
 

This command returns the size of "file" in bytes.

To get other stats about a file, use "guestfs_stat", "guestfs_lstat", "guestfs_is_dir", "guestfs_is_file" etc. To get the size of block devices, use "guestfs_blockdev_getsize64".

On error this function returns -1.

guestfs_fill

  int guestfs_fill (guestfs_h *g,
                 int c,
                 int len,
                 const char *path);
 
 

This command creates a new file called "path". The initial content of the file is "len" octets of "c", where "c" must be a number in the range "[0..255]".

To fill a file with zero bytes (sparsely), it is much more efficient to use "guestfs_truncate_size". To create a file with a pattern of repeating bytes use "guestfs_fill_pattern".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress callback. See ``guestfs_set_progress_callback'' in guestfs(3).

guestfs_fill_pattern

  int guestfs_fill_pattern (guestfs_h *g,
                 const char *pattern,
                 int len,
                 const char *path);
 
 

This function is like "guestfs_fill" except that it creates a new file of length "len" containing the repeating pattern of bytes in "pattern". The pattern is truncated if necessary to ensure the length of the file is exactly "len" bytes.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress callback. See ``guestfs_set_progress_callback'' in guestfs(3).

guestfs_find

  char **guestfs_find (guestfs_h *g,
                 const char *directory);
 
 

This command lists out all files and directories, recursively, starting at "directory". It is essentially equivalent to running the shell command "find directory -print" but some post-processing happens on the output, described below.

This returns a list of strings without any prefix. Thus if the directory structure was:

  /tmp/a
  /tmp/b
  /tmp/c/d
 
 

then the returned list from "guestfs_find" "/tmp" would be 4 elements:

  a
  b
  c
  c/d
 
 

If "directory" is not a directory, then this command returns an error.

The returned list is sorted.

See also "guestfs_find0".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_find0

  int guestfs_find0 (guestfs_h *g,
                 const char *directory,
                 const char *files);
 
 

This command lists out all files and directories, recursively, starting at "directory", placing the resulting list in the external file called "files".

This command works the same way as "guestfs_find" with the following exceptions:

*

The resulting list is written to an external file.

*

Items (filenames) in the result are separated by "\0" characters. See find(1) option -print0.

*

This command is not limited in the number of names that it can return.

*

The result list is not sorted.

This function returns 0 on success or -1 on error.

guestfs_findfs_label

  char *guestfs_findfs_label (guestfs_h *g,
                 const char *label);
 
 

This command searches the filesystems and returns the one which has the given label. An error is returned if no such filesystem can be found.

To find the label of a filesystem, use "guestfs_vfs_label".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_findfs_uuid

  char *guestfs_findfs_uuid (guestfs_h *g,
                 const char *uuid);
 
 

This command searches the filesystems and returns the one which has the given UUID. An error is returned if no such filesystem can be found.

To find the UUID of a filesystem, use "guestfs_vfs_uuid".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_fsck

  int guestfs_fsck (guestfs_h *g,
                 const char *fstype,
                 const char *device);
 
 

This runs the filesystem checker (fsck) on "device" which should have filesystem type "fstype".

The returned integer is the status. See fsck(8) for the list of status codes from "fsck".

Notes:

*

Multiple status codes can be summed together.

*

A non-zero return code can mean ``success'', for example if errors have been corrected on the filesystem.

*

Checking or repairing NTFS volumes is not supported (by linux-ntfs).

This command is entirely equivalent to running "fsck -a -t fstype device".

On error this function returns -1.

guestfs_get_append

  const char *guestfs_get_append (guestfs_h *g);
 
 

Return the additional kernel options which are added to the guest kernel command line.

If "NULL" then no options are added.

This function returns a string which may be NULL. There is no way to return an error from this function. The string is owned by the guest handle and must not be freed.

guestfs_get_autosync

  int guestfs_get_autosync (guestfs_h *g);
 
 

Get the autosync flag.

This function returns a C truth value on success or -1 on error.

guestfs_get_direct

  int guestfs_get_direct (guestfs_h *g);
 
 

Return the direct appliance mode flag.

This function returns a C truth value on success or -1 on error.

guestfs_get_e2label

  char *guestfs_get_e2label (guestfs_h *g,
                 const char *device);
 
 

This returns the ext2/3/4 filesystem label of the filesystem on "device".

This function returns a string, or NULL on error. The caller must free the returned string after use.

This function is deprecated. In new code, use the "vfs_label" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

guestfs_get_e2uuid

  char *guestfs_get_e2uuid (guestfs_h *g,
                 const char *device);
 
 

This returns the ext2/3/4 filesystem UUID of the filesystem on "device".

This function returns a string, or NULL on error. The caller must free the returned string after use.

This function is deprecated. In new code, use the "vfs_uuid" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

guestfs_get_memsize

  int guestfs_get_memsize (guestfs_h *g);
 
 

This gets the memory size in megabytes allocated to the qemu subprocess.

If "guestfs_set_memsize" was not called on this handle, and if "LIBGUESTFS_MEMSIZE" was not set, then this returns the compiled-in default value for memsize.

For more information on the architecture of libguestfs, see guestfs(3).

On error this function returns -1.

guestfs_get_network

  int guestfs_get_network (guestfs_h *g);
 
 

This returns the enable network flag.

This function returns a C truth value on success or -1 on error.

guestfs_get_path

  const char *guestfs_get_path (guestfs_h *g);
 
 

Return the current search path.

This is always non-NULL. If it wasn't set already, then this will return the default path.

This function returns a string, or NULL on error. The string is owned by the guest handle and must not be freed.

guestfs_get_pid

  int guestfs_get_pid (guestfs_h *g);
 
 

Return the process ID of the qemu subprocess. If there is no qemu subprocess, then this will return an error.

This is an internal call used for debugging and testing.

On error this function returns -1.

guestfs_get_qemu

  const char *guestfs_get_qemu (guestfs_h *g);
 
 

Return the current qemu binary.

This is always non-NULL. If it wasn't set already, then this will return the default qemu binary name.

This function returns a string, or NULL on error. The string is owned by the guest handle and must not be freed.

guestfs_get_recovery_proc

  int guestfs_get_recovery_proc (guestfs_h *g);
 
 

Return the recovery process enabled flag.

This function returns a C truth value on success or -1 on error.

guestfs_get_selinux

  int guestfs_get_selinux (guestfs_h *g);
 
 

This returns the current setting of the selinux flag which is passed to the appliance at boot time. See "guestfs_set_selinux".

For more information on the architecture of libguestfs, see guestfs(3).

This function returns a C truth value on success or -1 on error.

guestfs_get_state

  int guestfs_get_state (guestfs_h *g);
 
 

This returns the current state as an opaque integer. This is only useful for printing debug and internal error messages.

For more information on states, see guestfs(3).

On error this function returns -1.

guestfs_get_trace

  int guestfs_get_trace (guestfs_h *g);
 
 

Return the command trace flag.

This function returns a C truth value on success or -1 on error.

guestfs_get_umask

  int guestfs_get_umask (guestfs_h *g);
 
 

Return the current umask. By default the umask is 022 unless it has been set by calling "guestfs_umask".

On error this function returns -1.

guestfs_get_verbose

  int guestfs_get_verbose (guestfs_h *g);
 
 

This returns the verbose messages flag.

This function returns a C truth value on success or -1 on error.

guestfs_getcon

  char *guestfs_getcon (guestfs_h *g);
 
 

This gets the SELinux security context of the daemon.

See the documentation about SELINUX in guestfs(3), and "guestfs_setcon"

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_getxattrs

  struct guestfs_xattr_list *guestfs_getxattrs (guestfs_h *g,
                 const char *path);
 
 

This call lists the extended attributes of the file or directory "path".

At the system call level, this is a combination of the listxattr(2) and getxattr(2) calls.

See also: "guestfs_lgetxattrs", attr(5).

This function returns a "struct guestfs_xattr_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_xattr_list" after use.

guestfs_glob_expand

  char **guestfs_glob_expand (guestfs_h *g,
                 const char *pattern);
 
 

This command searches for all the pathnames matching "pattern" according to the wildcard expansion rules used by the shell.

If no paths match, then this returns an empty list (note: not an error).

It is just a wrapper around the C glob(3) function with flags "GLOB_MARK|GLOB_BRACE". See that manual page for more details.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_grep

  char **guestfs_grep (guestfs_h *g,
                 const char *regex,
                 const char *path);
 
 

This calls the external "grep" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_grepi

  char **guestfs_grepi (guestfs_h *g,
                 const char *regex,
                 const char *path);
 
 

This calls the external "grep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_grub_install

  int guestfs_grub_install (guestfs_h *g,
                 const char *root,
                 const char *device);
 
 

This command installs GRUB (the Grand Unified Bootloader) on "device", with the root directory being "root".

Note: If grub-install reports the error ``No suitable drive was found in the generated device map.'' it may be that you need to create a "/boot/grub/device.map" file first that contains the mapping between grub device names and Linux device names. It is usually sufficient to create a file containing:

  (hd0) /dev/vda
 
 

replacing "/dev/vda" with the name of the installation device.

This function returns 0 on success or -1 on error.

guestfs_head

  char **guestfs_head (guestfs_h *g,
                 const char *path);
 
 

This command returns up to the first 10 lines of a file as a list of strings.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_head_n

  char **guestfs_head_n (guestfs_h *g,
                 int nrlines,
                 const char *path);
 
 

If the parameter "nrlines" is a positive number, this returns the first "nrlines" lines of the file "path".

If the parameter "nrlines" is a negative number, this returns lines from the file "path", excluding the last "nrlines" lines.

If the parameter "nrlines" is zero, this returns an empty list.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_hexdump

  char *guestfs_hexdump (guestfs_h *g,
                 const char *path);
 
 

This runs "hexdump -C" on the given "path". The result is the human-readable, canonical hex dump of the file.

This function returns a string, or NULL on error. The caller must free the returned string after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_initrd_cat

  char *guestfs_initrd_cat (guestfs_h *g,
                 const char *initrdpath,
                 const char *filename,
                 size_t *size_r);
 
 

This command unpacks the file "filename" from the initrd file called "initrdpath". The filename must be given without the initial "/" character.

For example, in guestfish you could use the following command to examine the boot script (usually called "/init") contained in a Linux initrd or initramfs image:

  initrd-cat /boot/initrd-<version>.img init
 
 

See also "guestfs_initrd_list".

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_initrd_list

  char **guestfs_initrd_list (guestfs_h *g,
                 const char *path);
 
 

This command lists out files contained in an initrd.

The files are listed without any initial "/" character. The files are listed in the order they appear (not necessarily alphabetical). Directory names are listed as separate items.

Old Linux kernels (2.4 and earlier) used a compressed ext2 filesystem as initrd. We only support the newer initramfs format (compressed cpio files).

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_inotify_add_watch

  int64_t guestfs_inotify_add_watch (guestfs_h *g,
                 const char *path,
                 int mask);
 
 

Watch "path" for the events listed in "mask".

Note that if "path" is a directory then events within that directory are watched, but this does not happen recursively (in subdirectories).

Note for non-C or non-Linux callers: the inotify events are defined by the Linux kernel ABI and are listed in "/usr/include/sys/inotify.h".

On error this function returns -1.

guestfs_inotify_close

  int guestfs_inotify_close (guestfs_h *g);
 
 

This closes the inotify handle which was previously opened by inotify_init. It removes all watches, throws away any pending events, and deallocates all resources.

This function returns 0 on success or -1 on error.

guestfs_inotify_files

  char **guestfs_inotify_files (guestfs_h *g);
 
 

This function is a helpful wrapper around "guestfs_inotify_read" which just returns a list of pathnames of objects that were touched. The returned pathnames are sorted and deduplicated.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_inotify_init

  int guestfs_inotify_init (guestfs_h *g,
                 int maxevents);
 
 

This command creates a new inotify handle. The inotify subsystem can be used to notify events which happen to objects in the guest filesystem.

"maxevents" is the maximum number of events which will be queued up between calls to "guestfs_inotify_read" or "guestfs_inotify_files". If this is passed as 0, then the kernel (or previously set) default is used. For Linux 2.6.29 the default was 16384 events. Beyond this limit, the kernel throws away events, but records the fact that it threw them away by setting a flag "IN_Q_OVERFLOW" in the returned structure list (see "guestfs_inotify_read").

Before any events are generated, you have to add some watches to the internal watch list. See: "guestfs_inotify_add_watch", "guestfs_inotify_rm_watch" and "guestfs_inotify_watch_all".

Queued up events should be read periodically by calling "guestfs_inotify_read" (or "guestfs_inotify_files" which is just a helpful wrapper around "guestfs_inotify_read"). If you don't read the events out often enough then you risk the internal queue overflowing.

The handle should be closed after use by calling "guestfs_inotify_close". This also removes any watches automatically.

See also inotify(7) for an overview of the inotify interface as exposed by the Linux kernel, which is roughly what we expose via libguestfs. Note that there is one global inotify handle per libguestfs instance.

This function returns 0 on success or -1 on error.

guestfs_inotify_read

  struct guestfs_inotify_event_list *guestfs_inotify_read (guestfs_h *g);
 
 

Return the complete queue of events that have happened since the previous read call.

If no events have happened, this returns an empty list.

Note: In order to make sure that all events have been read, you must call this function repeatedly until it returns an empty list. The reason is that the call will read events up to the maximum appliance-to-host message size and leave remaining events in the queue.

This function returns a "struct guestfs_inotify_event_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_inotify_event_list" after use.

guestfs_inotify_rm_watch

  int guestfs_inotify_rm_watch (guestfs_h *g,
                 int wd);
 
 

Remove a previously defined inotify watch. See "guestfs_inotify_add_watch".

This function returns 0 on success or -1 on error.

guestfs_inspect_get_arch

  char *guestfs_inspect_get_arch (guestfs_h *g,
                 const char *root);
 
 

This function should only be called with a root device string as returned by "guestfs_inspect_os".

This returns the architecture of the inspected operating system. The possible return values are listed under "guestfs_file_architecture".

If the architecture could not be determined, then the string "unknown" is returned.

Please read ``INSPECTION'' in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_inspect_get_distro

  char *guestfs_inspect_get_distro (guestfs_h *g,
                 const char *root);
 
 

This function should only be called with a root device string as returned by "guestfs_inspect_os".

This returns the distro (distribution) of the inspected operating system.

Currently defined distros are:

debian

Debian or a Debian-derived distro such as Ubuntu.

fedora

Fedora.

redhat-based

Some Red Hat-derived distro.

rhel

Red Hat Enterprise Linux and some derivatives.

windows

Windows does not have distributions. This string is returned if the OS type is Windows.

unknown

The distro could not be determined.

Future versions of libguestfs may return other strings here. The caller should be prepared to handle any string.

Please read ``INSPECTION'' in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_inspect_get_filesystems

  char **guestfs_inspect_get_filesystems (guestfs_h *g,
                 const char *root);
 
 

This function should only be called with a root device string as returned by "guestfs_inspect_os".

This returns a list of all the filesystems that we think are associated with this operating system. This includes the root filesystem, other ordinary filesystems, and non-mounted devices like swap partitions.

In the case of a multi-boot virtual machine, it is possible for a filesystem to be shared between operating systems.

Please read ``INSPECTION'' in guestfs(3) for more details. See also "guestfs_inspect_get_mountpoints".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_inspect_get_major_version

  int guestfs_inspect_get_major_version (guestfs_h *g,
                 const char *root);
 
 

This function should only be called with a root device string as returned by "guestfs_inspect_os".

This returns the major version number of the inspected operating system.

Windows uses a consistent versioning scheme which is not reflected in the popular public names used by the operating system. Notably the operating system known as ``Windows 7'' is really version 6.1 (ie. major = 6, minor = 1). You can find out the real versions corresponding to releases of Windows by consulting Wikipedia or MSDN.

If the version could not be determined, then 0 is returned.

Please read ``INSPECTION'' in guestfs(3) for more details.

On error this function returns -1.

guestfs_inspect_get_minor_version

  int guestfs_inspect_get_minor_version (guestfs_h *g,
                 const char *root);
 
 

This function should only be called with a root device string as returned by "guestfs_inspect_os".

This returns the minor version number of the inspected operating system.

If the version could not be determined, then 0 is returned.

Please read ``INSPECTION'' in guestfs(3) for more details. See also "guestfs_inspect_get_major_version".

On error this function returns -1.

guestfs_inspect_get_mountpoints

  char **guestfs_inspect_get_mountpoints (guestfs_h *g,
                 const char *root);
 
 

This function should only be called with a root device string as returned by "guestfs_inspect_os".

This returns a hash of where we think the filesystems associated with this operating system should be mounted. Callers should note that this is at best an educated guess made by reading configuration files such as "/etc/fstab".

Each element in the returned hashtable has a key which is the path of the mountpoint (eg. "/boot") and a value which is the filesystem that would be mounted there (eg. "/dev/sda1").

Non-mounted devices such as swap devices are not returned in this list.

Please read ``INSPECTION'' in guestfs(3) for more details. See also "guestfs_inspect_get_filesystems".

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

guestfs_inspect_get_product_name

  char *guestfs_inspect_get_product_name (guestfs_h *g,
                 const char *root);
 
 

This function should only be called with a root device string as returned by "guestfs_inspect_os".

This returns the product name of the inspected operating system. The product name is generally some freeform string which can be displayed to the user, but should not be parsed by programs.

If the product name could not be determined, then the string "unknown" is returned.

Please read ``INSPECTION'' in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_inspect_get_type

  char *guestfs_inspect_get_type (guestfs_h *g,
                 const char *root);
 
 

This function should only be called with a root device string as returned by "guestfs_inspect_os".

This returns the type of the inspected operating system. Currently defined types are:

linux

Any Linux-based operating system.

windows

Any Microsoft Windows operating system.

unknown

The operating system type could not be determined.

Future versions of libguestfs may return other strings here. The caller should be prepared to handle any string.

Please read ``INSPECTION'' in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_inspect_os

  char **guestfs_inspect_os (guestfs_h *g);
 
 

This function uses other libguestfs functions and certain heuristics to inspect the disk(s) (usually disks belonging to a virtual machine), looking for operating systems.

The list returned is empty if no operating systems were found.

If one operating system was found, then this returns a list with a single element, which is the name of the root filesystem of this operating system. It is also possible for this function to return a list containing more than one element, indicating a dual-boot or multi-boot virtual machine, with each element being the root filesystem of one of the operating systems.

You can pass the root string(s) returned to other "guestfs_inspect_get_*" functions in order to query further information about each operating system, such as the name and version.

This function uses other libguestfs features such as "guestfs_mount_ro" and "guestfs_umount_all" in order to mount and unmount filesystems and look at the contents. This should be called with no disks currently mounted. The function may also use Augeas, so any existing Augeas handle will be closed.

This function cannot decrypt encrypted disks. The caller must do that first (supplying the necessary keys) if the disk is encrypted.

Please read ``INSPECTION'' in guestfs(3) for more details.

See also "guestfs_list_filesystems".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_is_blockdev

  int guestfs_is_blockdev (guestfs_h *g,
                 const char *path);
 
 

This returns "true" if and only if there is a block device with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

guestfs_is_busy

  int guestfs_is_busy (guestfs_h *g);
 
 

This returns true iff this handle is busy processing a command (in the "BUSY" state).

For more information on states, see guestfs(3).

This function returns a C truth value on success or -1 on error.

guestfs_is_chardev

  int guestfs_is_chardev (guestfs_h *g,
                 const char *path);
 
 

This returns "true" if and only if there is a character device with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

guestfs_is_config

  int guestfs_is_config (guestfs_h *g);
 
 

This returns true iff this handle is being configured (in the "CONFIG" state).

For more information on states, see guestfs(3).

This function returns a C truth value on success or -1 on error.

guestfs_is_dir

  int guestfs_is_dir (guestfs_h *g,
                 const char *path);
 
 

This returns "true" if and only if there is a directory with the given "path" name. Note that it returns false for other objects like files.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

guestfs_is_fifo

  int guestfs_is_fifo (guestfs_h *g,
                 const char *path);
 
 

This returns "true" if and only if there is a FIFO (named pipe) with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

guestfs_is_file

  int guestfs_is_file (guestfs_h *g,
                 const char *path);
 
 

This returns "true" if and only if there is a regular file with the given "path" name. Note that it returns false for other objects like directories.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

guestfs_is_launching

  int guestfs_is_launching (guestfs_h *g);
 
 

This returns true iff this handle is launching the subprocess (in the "LAUNCHING" state).

For more information on states, see guestfs(3).

This function returns a C truth value on success or -1 on error.

guestfs_is_lv

  int guestfs_is_lv (guestfs_h *g,
                 const char *device);
 
 

This command tests whether "device" is a logical volume, and returns true iff this is the case.

This function returns a C truth value on success or -1 on error.

guestfs_is_ready

  int guestfs_is_ready (guestfs_h *g);
 
 

This returns true iff this handle is ready to accept commands (in the "READY" state).

For more information on states, see guestfs(3).

This function returns a C truth value on success or -1 on error.

guestfs_is_socket

  int guestfs_is_socket (guestfs_h *g,
                 const char *path);
 
 

This returns "true" if and only if there is a Unix domain socket with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

guestfs_is_symlink

  int guestfs_is_symlink (guestfs_h *g,
                 const char *path);
 
 

This returns "true" if and only if there is a symbolic link with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

guestfs_kill_subprocess

  int guestfs_kill_subprocess (guestfs_h *g);
 
 

This kills the qemu subprocess. You should never need to call this.

This function returns 0 on success or -1 on error.

guestfs_launch

  int guestfs_launch (guestfs_h *g);
 
 

Internally libguestfs is implemented by running a virtual machine using qemu(1).

You should call this after configuring the handle (eg. adding drives) but before performing any actions.

This function returns 0 on success or -1 on error.

guestfs_lchown

  int guestfs_lchown (guestfs_h *g,
                 int owner,
                 int group,
                 const char *path);
 
 

Change the file owner to "owner" and group to "group". This is like "guestfs_chown" but if "path" is a symlink then the link itself is changed, not the target.

Only numeric uid and gid are supported. If you want to use names, you will need to locate and parse the password file yourself (Augeas support makes this relatively easy).

This function returns 0 on success or -1 on error.

guestfs_lgetxattrs

  struct guestfs_xattr_list *guestfs_lgetxattrs (guestfs_h *g,
                 const char *path);
 
 

This is the same as "guestfs_getxattrs", but if "path" is a symbolic link, then it returns the extended attributes of the link itself.

This function returns a "struct guestfs_xattr_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_xattr_list" after use.

guestfs_list_devices

  char **guestfs_list_devices (guestfs_h *g);
 
 

List all the block devices.

The full block device names are returned, eg. "/dev/sda".

See also "guestfs_list_filesystems".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_list_filesystems

  char **guestfs_list_filesystems (guestfs_h *g);
 
 

This inspection command looks for filesystems on partitions, block devices and logical volumes, returning a list of devices containing filesystems and their type.

The return value is a hash, where the keys are the devices containing filesystems, and the values are the filesystem types. For example:

  "/dev/sda1" => "ntfs"
  "/dev/sda2" => "ext2"
  "/dev/vg_guest/lv_root" => "ext4"
  "/dev/vg_guest/lv_swap" => "swap"
 
 

The value can have the special value ``unknown'', meaning the content of the device is undetermined or empty. ``swap'' means a Linux swap partition.

This command runs other libguestfs commands, which might include "guestfs_mount" and "guestfs_umount", and therefore you should use this soon after launch and only when nothing is mounted.

Not all of the filesystems returned will be mountable. In particular, swap partitions are returned in the list. Also this command does not check that each filesystem found is valid and mountable, and some filesystems might be mountable but require special options. Filesystems may not all belong to a single logical operating system (use "guestfs_inspect_os" to look for OSes).

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

guestfs_list_partitions

  char **guestfs_list_partitions (guestfs_h *g);
 
 

List all the partitions detected on all block devices.

The full partition device names are returned, eg. "/dev/sda1"

This does not return logical volumes. For that you will need to call "guestfs_lvs".

See also "guestfs_list_filesystems".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_ll

  char *guestfs_ll (guestfs_h *g,
                 const char *directory);
 
 

List the files in "directory" (relative to the root directory, there is no cwd) in the format of 'ls -la'.

This command is mostly useful for interactive sessions. It is not intended that you try to parse the output string.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_ln

  int guestfs_ln (guestfs_h *g,
                 const char *target,
                 const char *linkname);
 
 

This command creates a hard link using the "ln" command.

This function returns 0 on success or -1 on error.

guestfs_ln_f

  int guestfs_ln_f (guestfs_h *g,
                 const char *target,
                 const char *linkname);
 
 

This command creates a hard link using the "ln -f" command. The "-f" option removes the link ("linkname") if it exists already.

This function returns 0 on success or -1 on error.

guestfs_ln_s

  int guestfs_ln_s (guestfs_h *g,
                 const char *target,
                 const char *linkname);
 
 

This command creates a symbolic link using the "ln -s" command.

This function returns 0 on success or -1 on error.

guestfs_ln_sf

  int guestfs_ln_sf (guestfs_h *g,
                 const char *target,
                 const char *linkname);
 
 

This command creates a symbolic link using the "ln -sf" command, The "-f" option removes the link ("linkname") if it exists already.

This function returns 0 on success or -1 on error.

guestfs_lremovexattr

  int guestfs_lremovexattr (guestfs_h *g,
                 const char *xattr,
                 const char *path);
 
 

This is the same as "guestfs_removexattr", but if "path" is a symbolic link, then it removes an extended attribute of the link itself.

This function returns 0 on success or -1 on error.

guestfs_ls

  char **guestfs_ls (guestfs_h *g,
                 const char *directory);
 
 

List the files in "directory" (relative to the root directory, there is no cwd). The '.' and '..' entries are not returned, but hidden files are shown.

This command is mostly useful for interactive sessions. Programs should probably use "guestfs_readdir" instead.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_lsetxattr

  int guestfs_lsetxattr (guestfs_h *g,
                 const char *xattr,
                 const char *val,
                 int vallen,
                 const char *path);
 
 

This is the same as "guestfs_setxattr", but if "path" is a symbolic link, then it sets an extended attribute of the link itself.

This function returns 0 on success or -1 on error.

guestfs_lstat

  struct guestfs_stat *guestfs_lstat (guestfs_h *g,
                 const char *path);
 
 

Returns file information for the given "path".

This is the same as "guestfs_stat" except that if "path" is a symbolic link, then the link is stat-ed, not the file it refers to.

This is the same as the lstat(2) system call.

This function returns a "struct guestfs_stat *", or NULL if there was an error. The caller must call "guestfs_free_stat" after use.

guestfs_lstatlist

  struct guestfs_stat_list *guestfs_lstatlist (guestfs_h *g,
                 const char *path,
                 char *const *names);
 
 

This call allows you to perform the "guestfs_lstat" operation on multiple files, where all files are in the directory "path". "names" is the list of files from this directory.

On return you get a list of stat structs, with a one-to-one correspondence to the "names" list. If any name did not exist or could not be lstat'd, then the "ino" field of that structure is set to "-1".

This call is intended for programs that want to efficiently list a directory contents without making many round-trips. See also "guestfs_lxattrlist" for a similarly efficient call for getting extended attributes. Very long directory listings might cause the protocol message size to be exceeded, causing this call to fail. The caller must split up such requests into smaller groups of names.

This function returns a "struct guestfs_stat_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_stat_list" after use.

guestfs_luks_add_key

  int guestfs_luks_add_key (guestfs_h *g,
                 const char *device,
                 const char *key,
                 const char *newkey,
                 int keyslot);
 
 

This command adds a new key on LUKS device "device". "key" is any existing key, and is used to access the device. "newkey" is the new key to add. "keyslot" is the key slot that will be replaced.

Note that if "keyslot" already contains a key, then this command will fail. You have to use "guestfs_luks_kill_slot" first to remove that key.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section ``KEYS AND PASSPHRASES'' for more information.

guestfs_luks_close

  int guestfs_luks_close (guestfs_h *g,
                 const char *device);
 
 

This closes a LUKS device that was created earlier by "guestfs_luks_open" or "guestfs_luks_open_ro". The "device" parameter must be the name of the LUKS mapping device (ie. "/dev/mapper/mapname") and not the name of the underlying block device.

This function returns 0 on success or -1 on error.

guestfs_luks_format

  int guestfs_luks_format (guestfs_h *g,
                 const char *device,
                 const char *key,
                 int keyslot);
 
 

This command erases existing data on "device" and formats the device as a LUKS encrypted device. "key" is the initial key, which is added to key slot "slot". (LUKS supports 8 key slots, numbered 0-7).

This function returns 0 on success or -1 on error.

This command is dangerous. Without careful use you can easily destroy all your data.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section ``KEYS AND PASSPHRASES'' for more information.

guestfs_luks_format_cipher

  int guestfs_luks_format_cipher (guestfs_h *g,
                 const char *device,
                 const char *key,
                 int keyslot,
                 const char *cipher);
 
 

This command is the same as "guestfs_luks_format" but it also allows you to set the "cipher" used.

This function returns 0 on success or -1 on error.

This command is dangerous. Without careful use you can easily destroy all your data.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section ``KEYS AND PASSPHRASES'' for more information.

guestfs_luks_kill_slot

  int guestfs_luks_kill_slot (guestfs_h *g,
                 const char *device,
                 const char *key,
                 int keyslot);
 
 

This command deletes the key in key slot "keyslot" from the encrypted LUKS device "device". "key" must be one of the other keys.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section ``KEYS AND PASSPHRASES'' for more information.

guestfs_luks_open

  int guestfs_luks_open (guestfs_h *g,
                 const char *device,
                 const char *key,
                 const char *mapname);
 
 

This command opens a block device which has been encrypted according to the Linux Unified Key Setup (LUKS) standard.

"device" is the encrypted block device or partition.

The caller must supply one of the keys associated with the LUKS block device, in the "key" parameter.

This creates a new block device called "/dev/mapper/mapname". Reads and writes to this block device are decrypted from and encrypted to the underlying "device" respectively.

If this block device contains LVM volume groups, then calling "guestfs_vgscan" followed by "guestfs_vg_activate_all" will make them visible.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section ``KEYS AND PASSPHRASES'' for more information.

guestfs_luks_open_ro

  int guestfs_luks_open_ro (guestfs_h *g,
                 const char *device,
                 const char *key,
                 const char *mapname);
 
 

This is the same as "guestfs_luks_open" except that a read-only mapping is created.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section ``KEYS AND PASSPHRASES'' for more information.

guestfs_lvcreate

  int guestfs_lvcreate (guestfs_h *g,
                 const char *logvol,
                 const char *volgroup,
                 int mbytes);
 
 

This creates an LVM logical volume called "logvol" on the volume group "volgroup", with "size" megabytes.

This function returns 0 on success or -1 on error.

guestfs_lvm_clear_filter

  int guestfs_lvm_clear_filter (guestfs_h *g);
 
 

This undoes the effect of "guestfs_lvm_set_filter". LVM will be able to see every block device.

This command also clears the LVM cache and performs a volume group scan.

This function returns 0 on success or -1 on error.

guestfs_lvm_remove_all

  int guestfs_lvm_remove_all (guestfs_h *g);
 
 

This command removes all LVM logical volumes, volume groups and physical volumes.

This function returns 0 on success or -1 on error.

This command is dangerous. Without careful use you can easily destroy all your data.

guestfs_lvm_set_filter

  int guestfs_lvm_set_filter (guestfs_h *g,
                 char *const *devices);
 
 

This sets the LVM device filter so that LVM will only be able to ``see'' the block devices in the list "devices", and will ignore all other attached block devices.

Where disk image(s) contain duplicate PVs or VGs, this command is useful to get LVM to ignore the duplicates, otherwise LVM can get confused. Note also there are two types of duplication possible: either cloned PVs/VGs which have identical UUIDs; or VGs that are not cloned but just happen to have the same name. In normal operation you cannot create this situation, but you can do it outside LVM, eg. by cloning disk images or by bit twiddling inside the LVM metadata.

This command also clears the LVM cache and performs a volume group scan.

You can filter whole block devices or individual partitions.

You cannot use this if any VG is currently in use (eg. contains a mounted filesystem), even if you are not filtering out that VG.

This function returns 0 on success or -1 on error.

guestfs_lvremove

  int guestfs_lvremove (guestfs_h *g,
                 const char *device);
 
 

Remove an LVM logical volume "device", where "device" is the path to the LV, such as "/dev/VG/LV".

You can also remove all LVs in a volume group by specifying the VG name, "/dev/VG".

This function returns 0 on success or -1 on error.

guestfs_lvrename

  int guestfs_lvrename (guestfs_h *g,
                 const char *logvol,
                 const char *newlogvol);
 
 

Rename a logical volume "logvol" with the new name "newlogvol".

This function returns 0 on success or -1 on error.

guestfs_lvresize

  int guestfs_lvresize (guestfs_h *g,
                 const char *device,
                 int mbytes);
 
 

This resizes (expands or shrinks) an existing LVM logical volume to "mbytes". When reducing, data in the reduced part is lost.

This function returns 0 on success or -1 on error.

guestfs_lvresize_free

  int guestfs_lvresize_free (guestfs_h *g,
                 const char *lv,
                 int percent);
 
 

This expands an existing logical volume "lv" so that it fills "pc"% of the remaining free space in the volume group. Commonly you would call this with pc = 100 which expands the logical volume as much as possible, using all remaining free space in the volume group.

This function returns 0 on success or -1 on error.

guestfs_lvs

  char **guestfs_lvs (guestfs_h *g);
 
 

List all the logical volumes detected. This is the equivalent of the lvs(8) command.

This returns a list of the logical volume device names (eg. "/dev/VolGroup00/LogVol00").

See also "guestfs_lvs_full", "guestfs_list_filesystems".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_lvs_full

  struct guestfs_lvm_lv_list *guestfs_lvs_full (guestfs_h *g);
 
 

List all the logical volumes detected. This is the equivalent of the lvs(8) command. The ``full'' version includes all fields.

This function returns a "struct guestfs_lvm_lv_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_lvm_lv_list" after use.

guestfs_lvuuid

  char *guestfs_lvuuid (guestfs_h *g,
                 const char *device);
 
 

This command returns the UUID of the LVM LV "device".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_lxattrlist

  struct guestfs_xattr_list *guestfs_lxattrlist (guestfs_h *g,
                 const char *path,
                 char *const *names);
 
 

This call allows you to get the extended attributes of multiple files, where all files are in the directory "path". "names" is the list of files from this directory.

On return you get a flat list of xattr structs which must be interpreted sequentially. The first xattr struct always has a zero-length "attrname". "attrval" in this struct is zero-length to indicate there was an error doing "lgetxattr" for this file, or is a C string which is a decimal number (the number of following attributes for this file, which could be "0"). Then after the first xattr struct are the zero or more attributes for the first named file. This repeats for the second and subsequent files.

This call is intended for programs that want to efficiently list a directory contents without making many round-trips. See also "guestfs_lstatlist" for a similarly efficient call for getting standard stats. Very long directory listings might cause the protocol message size to be exceeded, causing this call to fail. The caller must split up such requests into smaller groups of names.

This function returns a "struct guestfs_xattr_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_xattr_list" after use.

guestfs_mkdir

  int guestfs_mkdir (guestfs_h *g,
                 const char *path);
 
 

Create a directory named "path".

This function returns 0 on success or -1 on error.

guestfs_mkdir_mode

  int guestfs_mkdir_mode (guestfs_h *g,
                 const char *path,
                 int mode);
 
 

This command creates a directory, setting the initial permissions of the directory to "mode".

For common Linux filesystems, the actual mode which is set will be "mode & ~umask & 01777". Non-native-Linux filesystems may interpret the mode in other ways.

See also "guestfs_mkdir", "guestfs_umask"

This function returns 0 on success or -1 on error.

guestfs_mkdir_p

  int guestfs_mkdir_p (guestfs_h *g,
                 const char *path);
 
 

Create a directory named "path", creating any parent directories as necessary. This is like the "mkdir -p" shell command.

This function returns 0 on success or -1 on error.

guestfs_mkdtemp

  char *guestfs_mkdtemp (guestfs_h *g,
                 const char *template);
 
 

This command creates a temporary directory. The "template" parameter should be a full pathname for the temporary directory name with the final six characters being ``XXXXXX''.

For example: ``/tmp/myprogXXXXXX'' or ``/Temp/myprogXXXXXX'', the second one being suitable for Windows filesystems.

The name of the temporary directory that was created is returned.

The temporary directory is created with mode 0700 and is owned by root.

The caller is responsible for deleting the temporary directory and its contents after use.

See also: mkdtemp(3)

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_mke2fs_J

  int guestfs_mke2fs_J (guestfs_h *g,
                 const char *fstype,
                 int blocksize,
                 const char *device,
                 const char *journal);
 
 

This creates an ext2/3/4 filesystem on "device" with an external journal on "journal". It is equivalent to the command:

  mke2fs -t fstype -b blocksize -J device=<journal> <device>
 
 

See also "guestfs_mke2journal".

This function returns 0 on success or -1 on error.

guestfs_mke2fs_JL

  int guestfs_mke2fs_JL (guestfs_h *g,
                 const char *fstype,
                 int blocksize,
                 const char *device,
                 const char *label);
 
 

This creates an ext2/3/4 filesystem on "device" with an external journal on the journal labeled "label".

See also "guestfs_mke2journal_L".

This function returns 0 on success or -1 on error.

guestfs_mke2fs_JU

  int guestfs_mke2fs_JU (guestfs_h *g,
                 const char *fstype,
                 int blocksize,
                 const char *device,
                 const char *uuid);
 
 

This creates an ext2/3/4 filesystem on "device" with an external journal on the journal with UUID "uuid".

See also "guestfs_mke2journal_U".

This function returns 0 on success or -1 on error.

guestfs_mke2journal

  int guestfs_mke2journal (guestfs_h *g,
                 int blocksize,
                 const char *device);
 
 

This creates an ext2 external journal on "device". It is equivalent to the command:

  mke2fs -O journal_dev -b blocksize device
 
 

This function returns 0 on success or -1 on error.

guestfs_mke2journal_L

  int guestfs_mke2journal_L (guestfs_h *g,
                 int blocksize,
                 const char *label,
                 const char *device);
 
 

This creates an ext2 external journal on "device" with label "label".

This function returns 0 on success or -1 on error.

guestfs_mke2journal_U

  int guestfs_mke2journal_U (guestfs_h *g,
                 int blocksize,
                 const char *uuid,
                 const char *device);
 
 

This creates an ext2 external journal on "device" with UUID "uuid".

This function returns 0 on success or -1 on error.

guestfs_mkfifo

  int guestfs_mkfifo (guestfs_h *g,
                 int mode,
                 const char *path);
 
 

This call creates a FIFO (named pipe) called "path" with mode "mode". It is just a convenient wrapper around "guestfs_mknod".

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

guestfs_mkfs

  int guestfs_mkfs (guestfs_h *g,
                 const char *fstype,
                 const char *device);
 
 

This creates a filesystem on "device" (usually a partition or LVM logical volume). The filesystem type is "fstype", for example "ext3".

This function returns 0 on success or -1 on error.

guestfs_mkfs_b

  int guestfs_mkfs_b (guestfs_h *g,
                 const char *fstype,
                 int blocksize,
                 const char *device);
 
 

This call is similar to "guestfs_mkfs", but it allows you to control the block size of the resulting filesystem. Supported block sizes depend on the filesystem type, but typically they are 1024, 2048 or 4096 only.

For VFAT and NTFS the "blocksize" parameter is treated as the requested cluster size.

This function returns 0 on success or -1 on error.

guestfs_mkmountpoint

  int guestfs_mkmountpoint (guestfs_h *g,
                 const char *exemptpath);
 
 

"guestfs_mkmountpoint" and "guestfs_rmmountpoint" are specialized calls that can be used to create extra mountpoints before mounting the first filesystem.

These calls are only necessary in some very limited circumstances, mainly the case where you want to mount a mix of unrelated and/or read-only filesystems together.

For example, live CDs often contain a ``Russian doll'' nest of filesystems, an ISO outer layer, with a squashfs image inside, with an ext2/3 image inside that. You can unpack this as follows in guestfish:

  add-ro Fedora-11-i686-Live.iso
  run
  mkmountpoint /cd
  mkmountpoint /squash
  mkmountpoint /ext3
  mount /dev/sda /cd
  mount-loop /cd/LiveOS/squashfs.img /squash
  mount-loop /squash/LiveOS/ext3fs.img /ext3
 
 

The inner filesystem is now unpacked under the /ext3 mountpoint.

This function returns 0 on success or -1 on error.

guestfs_mknod

  int guestfs_mknod (guestfs_h *g,
                 int mode,
                 int devmajor,
                 int devminor,
                 const char *path);
 
 

This call creates block or character special devices, or named pipes (FIFOs).

The "mode" parameter should be the mode, using the standard constants. "devmajor" and "devminor" are the device major and minor numbers, only used when creating block and character special devices.

Note that, just like mknod(2), the mode must be bitwise OR'd with S_IFBLK, S_IFCHR, S_IFIFO or S_IFSOCK (otherwise this call just creates a regular file). These constants are available in the standard Linux header files, or you can use "guestfs_mknod_b", "guestfs_mknod_c" or "guestfs_mkfifo" which are wrappers around this command which bitwise OR in the appropriate constant for you.

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

guestfs_mknod_b

  int guestfs_mknod_b (guestfs_h *g,
                 int mode,
                 int devmajor,
                 int devminor,
                 const char *path);
 
 

This call creates a block device node called "path" with mode "mode" and device major/minor "devmajor" and "devminor". It is just a convenient wrapper around "guestfs_mknod".

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

guestfs_mknod_c

  int guestfs_mknod_c (guestfs_h *g,
                 int mode,
                 int devmajor,
                 int devminor,
                 const char *path);
 
 

This call creates a char device node called "path" with mode "mode" and device major/minor "devmajor" and "devminor". It is just a convenient wrapper around "guestfs_mknod".

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

guestfs_mkswap

  int guestfs_mkswap (guestfs_h *g,
                 const char *device);
 
 

Create a swap partition on "device".

This function returns 0 on success or -1 on error.

guestfs_mkswap_L

  int guestfs_mkswap_L (guestfs_h *g,
                 const char *label,
                 const char *device);
 
 

Create a swap partition on "device" with label "label".

Note that you cannot attach a swap label to a block device (eg. "/dev/sda"), just to a partition. This appears to be a limitation of the kernel or swap tools.

This function returns 0 on success or -1 on error.

guestfs_mkswap_U

  int guestfs_mkswap_U (guestfs_h *g,
                 const char *uuid,
                 const char *device);
 
 

Create a swap partition on "device" with UUID "uuid".

This function returns 0 on success or -1 on error.

guestfs_mkswap_file

  int guestfs_mkswap_file (guestfs_h *g,
                 const char *path);
 
 

Create a swap file.

This command just writes a swap file signature to an existing file. To create the file itself, use something like "guestfs_fallocate".

This function returns 0 on success or -1 on error.

guestfs_modprobe

  int guestfs_modprobe (guestfs_h *g,
                 const char *modulename);
 
 

This loads a kernel module in the appliance.

The kernel module must have been whitelisted when libguestfs was built (see "appliance/kmod.whitelist.in" in the source).

This function returns 0 on success or -1 on error.

guestfs_mount

  int guestfs_mount (guestfs_h *g,
                 const char *device,
                 const char *mountpoint);
 
 

Mount a guest disk at a position in the filesystem. Block devices are named "/dev/sda", "/dev/sdb" and so on, as they were added to the guest. If those block devices contain partitions, they will have the usual names (eg. "/dev/sda1"). Also LVM "/dev/VG/LV"-style names can be used.

The rules are the same as for mount(2): A filesystem must first be mounted on "/" before others can be mounted. Other filesystems can only be mounted on directories which already exist.

The mounted filesystem is writable, if we have sufficient permissions on the underlying device.

Important note: When you use this call, the filesystem options "sync" and "noatime" are set implicitly. This was originally done because we thought it would improve reliability, but it turns out that -o sync has a very large negative performance impact and negligible effect on reliability. Therefore we recommend that you avoid using "guestfs_mount" in any code that needs performance, and instead use "guestfs_mount_options" (use an empty string for the first parameter if you don't want any options).

This function returns 0 on success or -1 on error.

guestfs_mount_loop

  int guestfs_mount_loop (guestfs_h *g,
                 const char *file,
                 const char *mountpoint);
 
 

This command lets you mount "file" (a filesystem image in a file) on a mount point. It is entirely equivalent to the command "mount -o loop file mountpoint".

This function returns 0 on success or -1 on error.

guestfs_mount_options

  int guestfs_mount_options (guestfs_h *g,
                 const char *options,
                 const char *device,
                 const char *mountpoint);
 
 

This is the same as the "guestfs_mount" command, but it allows you to set the mount options as for the mount(8) -o flag.

If the "options" parameter is an empty string, then no options are passed (all options default to whatever the filesystem uses).

This function returns 0 on success or -1 on error.

guestfs_mount_ro

  int guestfs_mount_ro (guestfs_h *g,
                 const char *device,
                 const char *mountpoint);
 
 

This is the same as the "guestfs_mount" command, but it mounts the filesystem with the read-only (-o ro) flag.

This function returns 0 on success or -1 on error.

guestfs_mount_vfs

  int guestfs_mount_vfs (guestfs_h *g,
                 const char *options,
                 const char *vfstype,
                 const char *device,
                 const char *mountpoint);
 
 

This is the same as the "guestfs_mount" command, but it allows you to set both the mount options and the vfstype as for the mount(8) -o and -t flags.

This function returns 0 on success or -1 on error.

guestfs_mountpoints

  char **guestfs_mountpoints (guestfs_h *g);
 
 

This call is similar to "guestfs_mounts". That call returns a list of devices. This one returns a hash table (map) of device name to directory where the device is mounted.

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

guestfs_mounts

  char **guestfs_mounts (guestfs_h *g);
 
 

This returns the list of currently mounted filesystems. It returns the list of devices (eg. "/dev/sda1", "/dev/VG/LV").

Some internal mounts are not shown.

See also: "guestfs_mountpoints"

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_mv

  int guestfs_mv (guestfs_h *g,
                 const char *src,
                 const char *dest);
 
 

This moves a file from "src" to "dest" where "dest" is either a destination filename or destination directory.

This function returns 0 on success or -1 on error.

guestfs_ntfs_3g_probe

  int guestfs_ntfs_3g_probe (guestfs_h *g,
                 int rw,
                 const char *device);
 
 

This command runs the ntfs-3g.probe(8) command which probes an NTFS "device" for mountability. (Not all NTFS volumes can be mounted read-write, and some cannot be mounted at all).

"rw" is a boolean flag. Set it to true if you want to test if the volume can be mounted read-write. Set it to false if you want to test if the volume can be mounted read-only.

The return value is an integer which 0 if the operation would succeed, or some non-zero value documented in the ntfs-3g.probe(8) manual page.

On error this function returns -1.

guestfs_ntfsresize

  int guestfs_ntfsresize (guestfs_h *g,
                 const char *device);
 
 

This command resizes an NTFS filesystem, expanding or shrinking it to the size of the underlying device. See also ntfsresize(8).

This function returns 0 on success or -1 on error.

guestfs_ntfsresize_size

  int guestfs_ntfsresize_size (guestfs_h *g,
                 const char *device,
                 int64_t size);
 
 

This command is the same as "guestfs_ntfsresize" except that it allows you to specify the new size (in bytes) explicitly.

This function returns 0 on success or -1 on error.

guestfs_part_add

  int guestfs_part_add (guestfs_h *g,
                 const char *device,
                 const char *prlogex,
                 int64_t startsect,
                 int64_t endsect);
 
 

This command adds a partition to "device". If there is no partition table on the device, call "guestfs_part_init" first.

The "prlogex" parameter is the type of partition. Normally you should pass "p" or "primary" here, but MBR partition tables also support "l" (or "logical") and "e" (or "extended") partition types.

"startsect" and "endsect" are the start and end of the partition in sectors. "endsect" may be negative, which means it counts backwards from the end of the disk ("-1" is the last sector).

Creating a partition which covers the whole disk is not so easy. Use "guestfs_part_disk" to do that.

This function returns 0 on success or -1 on error.

guestfs_part_del

  int guestfs_part_del (guestfs_h *g,
                 const char *device,
                 int partnum);
 
 

This command deletes the partition numbered "partnum" on "device".

Note that in the case of MBR partitioning, deleting an extended partition also deletes any logical partitions it contains.

This function returns 0 on success or -1 on error.

guestfs_part_disk

  int guestfs_part_disk (guestfs_h *g,
                 const char *device,
                 const char *parttype);
 
 

This command is simply a combination of "guestfs_part_init" followed by "guestfs_part_add" to create a single primary partition covering the whole disk.

"parttype" is the partition table type, usually "mbr" or "gpt", but other possible values are described in "guestfs_part_init".

This function returns 0 on success or -1 on error.

This command is dangerous. Without careful use you can easily destroy all your data.

guestfs_part_get_bootable

  int guestfs_part_get_bootable (guestfs_h *g,
                 const char *device,
                 int partnum);
 
 

This command returns true if the partition "partnum" on "device" has the bootable flag set.

See also "guestfs_part_set_bootable".

This function returns a C truth value on success or -1 on error.

guestfs_part_get_mbr_id

  int guestfs_part_get_mbr_id (guestfs_h *g,
                 const char *device,
                 int partnum);
 
 

Returns the MBR type byte (also known as the ID byte) from the numbered partition "partnum".

Note that only MBR (old DOS-style) partitions have type bytes. You will get undefined results for other partition table types (see "guestfs_part_get_parttype").

On error this function returns -1.

guestfs_part_get_parttype

  char *guestfs_part_get_parttype (guestfs_h *g,
                 const char *device);
 
 

This command examines the partition table on "device" and returns the partition table type (format) being used.

Common return values include: "msdos" (a DOS/Windows style MBR partition table), "gpt" (a GPT/EFI-style partition table). Other values are possible, although unusual. See "guestfs_part_init" for a full list.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_part_init

  int guestfs_part_init (guestfs_h *g,
                 const char *device,
                 const char *parttype);
 
 

This creates an empty partition table on "device" of one of the partition types listed below. Usually "parttype" should be either "msdos" or "gpt" (for large disks).

Initially there are no partitions. Following this, you should call "guestfs_part_add" for each partition required.

Possible values for "parttype" are:

efi | gpt

Intel EFI / GPT partition table.

This is recommended for >= 2 TB partitions that will be accessed from Linux and Intel-based Mac OS X. It also has limited backwards compatibility with the "mbr" format.

mbr | msdos

The standard PC ``Master Boot Record'' (MBR) format used by MS-DOS and Windows. This partition type will only work for device sizes up to 2 TB. For large disks we recommend using "gpt".

Other partition table types that may work but are not supported include:

aix

AIX disk labels.

amiga | rdb

Amiga ``Rigid Disk Block'' format.

bsd

BSD disk labels.

dasd

DASD, used on IBM mainframes.

dvh

MIPS/SGI volumes.

mac

Old Mac partition format. Modern Macs use "gpt".

pc98

NEC PC-98 format, common in Japan apparently.

sun

Sun disk labels.

This function returns 0 on success or -1 on error.

guestfs_part_list

  struct guestfs_partition_list *guestfs_part_list (guestfs_h *g,
                 const char *device);
 
 

This command parses the partition table on "device" and returns the list of partitions found.

The fields in the returned structure are:

part_num

Partition number, counting from 1.

part_start

Start of the partition in bytes. To get sectors you have to divide by the device's sector size, see "guestfs_blockdev_getss".

part_end

End of the partition in bytes.

part_size

Size of the partition in bytes.

This function returns a "struct guestfs_partition_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_partition_list" after use.

guestfs_part_set_bootable

  int guestfs_part_set_bootable (guestfs_h *g,
                 const char *device,
                 int partnum,
                 int bootable);
 
 

This sets the bootable flag on partition numbered "partnum" on device "device". Note that partitions are numbered from 1.

The bootable flag is used by some operating systems (notably Windows) to determine which partition to boot from. It is by no means universally recognized.

This function returns 0 on success or -1 on error.

guestfs_part_set_mbr_id

  int guestfs_part_set_mbr_id (guestfs_h *g,
                 const char *device,
                 int partnum,
                 int idbyte);
 
 

Sets the MBR type byte (also known as the ID byte) of the numbered partition "partnum" to "idbyte". Note that the type bytes quoted in most documentation are in fact hexadecimal numbers, but usually documented without any leading ``0x'' which might be confusing.

Note that only MBR (old DOS-style) partitions have type bytes. You will get undefined results for other partition table types (see "guestfs_part_get_parttype").

This function returns 0 on success or -1 on error.

guestfs_part_set_name

  int guestfs_part_set_name (guestfs_h *g,
                 const char *device,
                 int partnum,
                 const char *name);
 
 

This sets the partition name on partition numbered "partnum" on device "device". Note that partitions are numbered from 1.

The partition name can only be set on certain types of partition table. This works on "gpt" but not on "mbr" partitions.

This function returns 0 on success or -1 on error.

guestfs_part_to_dev

  char *guestfs_part_to_dev (guestfs_h *g,
                 const char *partition);
 
 

This function takes a partition name (eg. ``/dev/sdb1'') and removes the partition number, returning the device name (eg. ``/dev/sdb'').

The named partition must exist, for example as a string returned from "guestfs_list_partitions".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_ping_daemon

  int guestfs_ping_daemon (guestfs_h *g);
 
 

This is a test probe into the guestfs daemon running inside the qemu subprocess. Calling this function checks that the daemon responds to the ping message, without affecting the daemon or attached block device(s) in any other way.

This function returns 0 on success or -1 on error.

guestfs_pread

  char *guestfs_pread (guestfs_h *g,
                 const char *path,
                 int count,
                 int64_t offset,
                 size_t *size_r);
 
 

This command lets you read part of a file. It reads "count" bytes of the file, starting at "offset", from file "path".

This may read fewer bytes than requested. For further details see the pread(2) system call.

See also "guestfs_pwrite", "guestfs_pread_device".

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_pread_device

  char *guestfs_pread_device (guestfs_h *g,
                 const char *device,
                 int count,
                 int64_t offset,
                 size_t *size_r);
 
 

This command lets you read part of a file. It reads "count" bytes of "device", starting at "offset".

This may read fewer bytes than requested. For further details see the pread(2) system call.

See also "guestfs_pread".

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_pvcreate

  int guestfs_pvcreate (guestfs_h *g,
                 const char *device);
 
 

This creates an LVM physical volume on the named "device", where "device" should usually be a partition name such as "/dev/sda1".

This function returns 0 on success or -1 on error.

guestfs_pvremove

  int guestfs_pvremove (guestfs_h *g,
                 const char *device);
 
 

This wipes a physical volume "device" so that LVM will no longer recognise it.

The implementation uses the "pvremove" command which refuses to wipe physical volumes that contain any volume groups, so you have to remove those first.

This function returns 0 on success or -1 on error.

guestfs_pvresize

  int guestfs_pvresize (guestfs_h *g,
                 const char *device);
 
 

This resizes (expands or shrinks) an existing LVM physical volume to match the new size of the underlying device.

This function returns 0 on success or -1 on error.

guestfs_pvresize_size

  int guestfs_pvresize_size (guestfs_h *g,
                 const char *device,
                 int64_t size);
 
 

This command is the same as "guestfs_pvresize" except that it allows you to specify the new size (in bytes) explicitly.

This function returns 0 on success or -1 on error.

guestfs_pvs

  char **guestfs_pvs (guestfs_h *g);
 
 

List all the physical volumes detected. This is the equivalent of the pvs(8) command.

This returns a list of just the device names that contain PVs (eg. "/dev/sda2").

See also "guestfs_pvs_full".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_pvs_full

  struct guestfs_lvm_pv_list *guestfs_pvs_full (guestfs_h *g);
 
 

List all the physical volumes detected. This is the equivalent of the pvs(8) command. The ``full'' version includes all fields.

This function returns a "struct guestfs_lvm_pv_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_lvm_pv_list" after use.

guestfs_pvuuid

  char *guestfs_pvuuid (guestfs_h *g,
                 const char *device);
 
 

This command returns the UUID of the LVM PV "device".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_pwrite

  int guestfs_pwrite (guestfs_h *g,
                 const char *path,
                 const char *content,
                 size_t content_size,
                 int64_t offset);
 
 

This command writes to part of a file. It writes the data buffer "content" to the file "path" starting at offset "offset".

This command implements the pwrite(2) system call, and like that system call it may not write the full data requested. The return value is the number of bytes that were actually written to the file. This could even be 0, although short writes are unlikely for regular files in ordinary circumstances.

See also "guestfs_pread", "guestfs_pwrite_device".

On error this function returns -1.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_pwrite_device

  int guestfs_pwrite_device (guestfs_h *g,
                 const char *device,
                 const char *content,
                 size_t content_size,
                 int64_t offset);
 
 

This command writes to part of a device. It writes the data buffer "content" to "device" starting at offset "offset".

This command implements the pwrite(2) system call, and like that system call it may not write the full data requested (although short writes to disk devices and partitions are probably impossible with standard Linux kernels).

See also "guestfs_pwrite".

On error this function returns -1.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_read_file

  char *guestfs_read_file (guestfs_h *g,
                 const char *path,
                 size_t *size_r);
 
 

This calls returns the contents of the file "path" as a buffer.

Unlike "guestfs_cat", this function can correctly handle files that contain embedded ASCII NUL characters. However unlike "guestfs_download", this function is limited in the total size of file that can be handled.

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_read_lines

  char **guestfs_read_lines (guestfs_h *g,
                 const char *path);
 
 

Return the contents of the file named "path".

The file contents are returned as a list of lines. Trailing "LF" and "CRLF" character sequences are not returned.

Note that this function cannot correctly handle binary files (specifically, files containing "\0" character which is treated as end of line). For those you need to use the "guestfs_read_file" function which has a more complex interface.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_readdir

  struct guestfs_dirent_list *guestfs_readdir (guestfs_h *g,
                 const char *dir);
 
 

This returns the list of directory entries in directory "dir".

All entries in the directory are returned, including "." and "..". The entries are not sorted, but returned in the same order as the underlying filesystem.

Also this call returns basic file type information about each file. The "ftyp" field will contain one of the following characters:

'b'

Block special

'c'

Char special

'd'

Directory

'f'

FIFO (named pipe)

'l'

Symbolic link

'r'

Regular file

's'

Socket

'u'

Unknown file type

'?'

The readdir(3) call returned a "d_type" field with an unexpected value

This function is primarily intended for use by programs. To get a simple list of names, use "guestfs_ls". To get a printable directory for human consumption, use "guestfs_ll".

This function returns a "struct guestfs_dirent_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_dirent_list" after use.

guestfs_readlink

  char *guestfs_readlink (guestfs_h *g,
                 const char *path);
 
 

This command reads the target of a symbolic link.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_readlinklist

  char **guestfs_readlinklist (guestfs_h *g,
                 const char *path,
                 char *const *names);
 
 

This call allows you to do a "readlink" operation on multiple files, where all files are in the directory "path". "names" is the list of files from this directory.

On return you get a list of strings, with a one-to-one correspondence to the "names" list. Each string is the value of the symbolic link.

If the readlink(2) operation fails on any name, then the corresponding result string is the empty string "". However the whole operation is completed even if there were readlink(2) errors, and so you can call this function with names where you don't know if they are symbolic links already (albeit slightly less efficient).

This call is intended for programs that want to efficiently list a directory contents without making many round-trips. Very long directory listings might cause the protocol message size to be exceeded, causing this call to fail. The caller must split up such requests into smaller groups of names.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_realpath

  char *guestfs_realpath (guestfs_h *g,
                 const char *path);
 
 

Return the canonicalized absolute pathname of "path". The returned path has no ".", ".." or symbolic link path elements.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_removexattr

  int guestfs_removexattr (guestfs_h *g,
                 const char *xattr,
                 const char *path);
 
 

This call removes the extended attribute named "xattr" of the file "path".

See also: "guestfs_lremovexattr", attr(5).

This function returns 0 on success or -1 on error.

guestfs_resize2fs

  int guestfs_resize2fs (guestfs_h *g,
                 const char *device);
 
 

This resizes an ext2, ext3 or ext4 filesystem to match the size of the underlying device.

Note: It is sometimes required that you run "guestfs_e2fsck_f" on the "device" before calling this command. For unknown reasons "resize2fs" sometimes gives an error about this and sometimes not. In any case, it is always safe to call "guestfs_e2fsck_f" before calling this function.

This function returns 0 on success or -1 on error.

guestfs_resize2fs_size

  int guestfs_resize2fs_size (guestfs_h *g,
                 const char *device,
                 int64_t size);
 
 

This command is the same as "guestfs_resize2fs" except that it allows you to specify the new size (in bytes) explicitly.

This function returns 0 on success or -1 on error.

guestfs_rm

  int guestfs_rm (guestfs_h *g,
                 const char *path);
 
 

Remove the single file "path".

This function returns 0 on success or -1 on error.

guestfs_rm_rf

  int guestfs_rm_rf (guestfs_h *g,
                 const char *path);
 
 

Remove the file or directory "path", recursively removing the contents if its a directory. This is like the "rm -rf" shell command.

This function returns 0 on success or -1 on error.

guestfs_rmdir

  int guestfs_rmdir (guestfs_h *g,
                 const char *path);
 
 

Remove the single directory "path".

This function returns 0 on success or -1 on error.

guestfs_rmmountpoint

  int guestfs_rmmountpoint (guestfs_h *g,
                 const char *exemptpath);
 
 

This calls removes a mountpoint that was previously created with "guestfs_mkmountpoint". See "guestfs_mkmountpoint" for full details.

This function returns 0 on success or -1 on error.

guestfs_scrub_device

  int guestfs_scrub_device (guestfs_h *g,
                 const char *device);
 
 

This command writes patterns over "device" to make data retrieval more difficult.

It is an interface to the scrub(1) program. See that manual page for more details.

This function returns 0 on success or -1 on error.

This command is dangerous. Without careful use you can easily destroy all your data.

guestfs_scrub_file

  int guestfs_scrub_file (guestfs_h *g,
                 const char *file);
 
 

This command writes patterns over a file to make data retrieval more difficult.

The file is removed after scrubbing.

It is an interface to the scrub(1) program. See that manual page for more details.

This function returns 0 on success or -1 on error.

guestfs_scrub_freespace

  int guestfs_scrub_freespace (guestfs_h *g,
                 const char *dir);
 
 

This command creates the directory "dir" and then fills it with files until the filesystem is full, and scrubs the files as for "guestfs_scrub_file", and deletes them. The intention is to scrub any free space on the partition containing "dir".

It is an interface to the scrub(1) program. See that manual page for more details.

This function returns 0 on success or -1 on error.

guestfs_set_append

  int guestfs_set_append (guestfs_h *g,
                 const char *append);
 
 

This function is used to add additional options to the guest kernel command line.

The default is "NULL" unless overridden by setting "LIBGUESTFS_APPEND" environment variable.

Setting "append" to "NULL" means no additional options are passed (libguestfs always adds a few of its own).

This function returns 0 on success or -1 on error.

guestfs_set_autosync

  int guestfs_set_autosync (guestfs_h *g,
                 int autosync);
 
 

If "autosync" is true, this enables autosync. Libguestfs will make a best effort attempt to run "guestfs_umount_all" followed by "guestfs_sync" when the handle is closed (also if the program exits without closing handles).

This is disabled by default (except in guestfish where it is enabled by default).

This function returns 0 on success or -1 on error.

guestfs_set_direct

  int guestfs_set_direct (guestfs_h *g,
                 int direct);
 
 

If the direct appliance mode flag is enabled, then stdin and stdout are passed directly through to the appliance once it is launched.

One consequence of this is that log messages aren't caught by the library and handled by "guestfs_set_log_message_callback", but go straight to stdout.

You probably don't want to use this unless you know what you are doing.

The default is disabled.

This function returns 0 on success or -1 on error.

guestfs_set_e2label

  int guestfs_set_e2label (guestfs_h *g,
                 const char *device,
                 const char *label);
 
 

This sets the ext2/3/4 filesystem label of the filesystem on "device" to "label". Filesystem labels are limited to 16 characters.

You can use either "guestfs_tune2fs_l" or "guestfs_get_e2label" to return the existing label on a filesystem.

This function returns 0 on success or -1 on error.

guestfs_set_e2uuid

  int guestfs_set_e2uuid (guestfs_h *g,
                 const char *device,
                 const char *uuid);
 
 

This sets the ext2/3/4 filesystem UUID of the filesystem on "device" to "uuid". The format of the UUID and alternatives such as "clear", "random" and "time" are described in the tune2fs(8) manpage.

You can use either "guestfs_tune2fs_l" or "guestfs_get_e2uuid" to return the existing UUID of a filesystem.

This function returns 0 on success or -1 on error.

guestfs_set_memsize

  int guestfs_set_memsize (guestfs_h *g,
                 int memsize);
 
 

This sets the memory size in megabytes allocated to the qemu subprocess. This only has any effect if called before "guestfs_launch".

You can also change this by setting the environment variable "LIBGUESTFS_MEMSIZE" before the handle is created.

For more information on the architecture of libguestfs, see guestfs(3).

This function returns 0 on success or -1 on error.

guestfs_set_network

  int guestfs_set_network (guestfs_h *g,
                 int network);
 
 

If "network" is true, then the network is enabled in the libguestfs appliance. The default is false.

This affects whether commands are able to access the network (see ``RUNNING COMMANDS'' in guestfs(3)).

You must call this before calling "guestfs_launch", otherwise it has no effect.

This function returns 0 on success or -1 on error.

guestfs_set_path

  int guestfs_set_path (guestfs_h *g,
                 const char *searchpath);
 
 

Set the path that libguestfs searches for kernel and initrd.img.

The default is "$libdir/guestfs" unless overridden by setting "LIBGUESTFS_PATH" environment variable.

Setting "path" to "NULL" restores the default path.

This function returns 0 on success or -1 on error.

guestfs_set_qemu

  int guestfs_set_qemu (guestfs_h *g,
                 const char *qemu);
 
 

Set the qemu binary that we will use.

The default is chosen when the library was compiled by the configure script.

You can also override this by setting the "LIBGUESTFS_QEMU" environment variable.

Setting "qemu" to "NULL" restores the default qemu binary.

Note that you should call this function as early as possible after creating the handle. This is because some pre-launch operations depend on testing qemu features (by running "qemu -help"). If the qemu binary changes, we don't retest features, and so you might see inconsistent results. Using the environment variable "LIBGUESTFS_QEMU" is safest of all since that picks the qemu binary at the same time as the handle is created.

This function returns 0 on success or -1 on error.

guestfs_set_recovery_proc

  int guestfs_set_recovery_proc (guestfs_h *g,
                 int recoveryproc);
 
 

If this is called with the parameter "false" then "guestfs_launch" does not create a recovery process. The purpose of the recovery process is to stop runaway qemu processes in the case where the main program aborts abruptly.

This only has any effect if called before "guestfs_launch", and the default is true.

About the only time when you would want to disable this is if the main process will fork itself into the background (``daemonize'' itself). In this case the recovery process thinks that the main program has disappeared and so kills qemu, which is not very helpful.

This function returns 0 on success or -1 on error.

guestfs_set_selinux

  int guestfs_set_selinux (guestfs_h *g,
                 int selinux);
 
 

This sets the selinux flag that is passed to the appliance at boot time. The default is "selinux=0" (disabled).

Note that if SELinux is enabled, it is always in Permissive mode ("enforcing=0").

For more information on the architecture of libguestfs, see guestfs(3).

This function returns 0 on success or -1 on error.

guestfs_set_trace

  int guestfs_set_trace (guestfs_h *g,
                 int trace);
 
 

If the command trace flag is set to 1, then commands are printed on stderr before they are executed in a format which is very similar to the one used by guestfish. In other words, you can run a program with this enabled, and you will get out a script which you can feed to guestfish to perform the same set of actions.

If you want to trace C API calls into libguestfs (and other libraries) then possibly a better way is to use the external ltrace(1) command.

Command traces are disabled unless the environment variable "LIBGUESTFS_TRACE" is defined and set to 1.

This function returns 0 on success or -1 on error.

guestfs_set_verbose

  int guestfs_set_verbose (guestfs_h *g,
                 int verbose);
 
 

If "verbose" is true, this turns on verbose messages (to "stderr").

Verbose messages are disabled unless the environment variable "LIBGUESTFS_DEBUG" is defined and set to 1.

This function returns 0 on success or -1 on error.

guestfs_setcon

  int guestfs_setcon (guestfs_h *g,
                 const char *context);
 
 

This sets the SELinux security context of the daemon to the string "context".

See the documentation about SELINUX in guestfs(3).

This function returns 0 on success or -1 on error.

guestfs_setxattr

  int guestfs_setxattr (guestfs_h *g,
                 const char *xattr,
                 const char *val,
                 int vallen,
                 const char *path);
 
 

This call sets the extended attribute named "xattr" of the file "path" to the value "val" (of length "vallen"). The value is arbitrary 8 bit data.

See also: "guestfs_lsetxattr", attr(5).

This function returns 0 on success or -1 on error.

guestfs_sfdisk

  int guestfs_sfdisk (guestfs_h *g,
                 const char *device,
                 int cyls,
                 int heads,
                 int sectors,
                 char *const *lines);
 
 

This is a direct interface to the sfdisk(8) program for creating partitions on block devices.

"device" should be a block device, for example "/dev/sda".

"cyls", "heads" and "sectors" are the number of cylinders, heads and sectors on the device, which are passed directly to sfdisk as the -C, -H and -S parameters. If you pass 0 for any of these, then the corresponding parameter is omitted. Usually for 'large' disks, you can just pass 0 for these, but for small (floppy-sized) disks, sfdisk (or rather, the kernel) cannot work out the right geometry and you will need to tell it.

"lines" is a list of lines that we feed to "sfdisk". For more information refer to the sfdisk(8) manpage.

To create a single partition occupying the whole disk, you would pass "lines" as a single element list, when the single element being the string "," (comma).

See also: "guestfs_sfdisk_l", "guestfs_sfdisk_N", "guestfs_part_init"

This function returns 0 on success or -1 on error.

This command is dangerous. Without careful use you can easily destroy all your data.

guestfs_sfdiskM

  int guestfs_sfdiskM (guestfs_h *g,
                 const char *device,
                 char *const *lines);
 
 

This is a simplified interface to the "guestfs_sfdisk" command, where partition sizes are specified in megabytes only (rounded to the nearest cylinder) and you don't need to specify the cyls, heads and sectors parameters which were rarely if ever used anyway.

See also: "guestfs_sfdisk", the sfdisk(8) manpage and "guestfs_part_disk"

This function returns 0 on success or -1 on error.

This command is dangerous. Without careful use you can easily destroy all your data.

guestfs_sfdisk_N

  int guestfs_sfdisk_N (guestfs_h *g,
                 const char *device,
                 int partnum,
                 int cyls,
                 int heads,
                 int sectors,
                 const char *line);
 
 

This runs sfdisk(8) option to modify just the single partition "n" (note: "n" counts from 1).

For other parameters, see "guestfs_sfdisk". You should usually pass 0 for the cyls/heads/sectors parameters.

See also: "guestfs_part_add"

This function returns 0 on success or -1 on error.

This command is dangerous. Without careful use you can easily destroy all your data.

guestfs_sfdisk_disk_geometry

  char *guestfs_sfdisk_disk_geometry (guestfs_h *g,
                 const char *device);
 
 

This displays the disk geometry of "device" read from the partition table. Especially in the case where the underlying block device has been resized, this can be different from the kernel's idea of the geometry (see "guestfs_sfdisk_kernel_geometry").

The result is in human-readable format, and not designed to be parsed.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_sfdisk_kernel_geometry

  char *guestfs_sfdisk_kernel_geometry (guestfs_h *g,
                 const char *device);
 
 

This displays the kernel's idea of the geometry of "device".

The result is in human-readable format, and not designed to be parsed.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_sfdisk_l

  char *guestfs_sfdisk_l (guestfs_h *g,
                 const char *device);
 
 

This displays the partition table on "device", in the human-readable output of the sfdisk(8) command. It is not intended to be parsed.

See also: "guestfs_part_list"

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_sh

  char *guestfs_sh (guestfs_h *g,
                 const char *command);
 
 

This call runs a command from the guest filesystem via the guest's "/bin/sh".

This is like "guestfs_command", but passes the command to:

  /bin/sh -c "command"
 
 

Depending on the guest's shell, this usually results in wildcards being expanded, shell expressions being interpolated and so on.

All the provisos about "guestfs_command" apply to this call.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_sh_lines

  char **guestfs_sh_lines (guestfs_h *g,
                 const char *command);
 
 

This is the same as "guestfs_sh", but splits the result into a list of lines.

See also: "guestfs_command_lines"

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_sleep

  int guestfs_sleep (guestfs_h *g,
                 int secs);
 
 

Sleep for "secs" seconds.

This function returns 0 on success or -1 on error.

guestfs_stat

  struct guestfs_stat *guestfs_stat (guestfs_h *g,
                 const char *path);
 
 

Returns file information for the given "path".

This is the same as the stat(2) system call.

This function returns a "struct guestfs_stat *", or NULL if there was an error. The caller must call "guestfs_free_stat" after use.

guestfs_statvfs

  struct guestfs_statvfs *guestfs_statvfs (guestfs_h *g,
                 const char *path);
 
 

Returns file system statistics for any mounted file system. "path" should be a file or directory in the mounted file system (typically it is the mount point itself, but it doesn't need to be).

This is the same as the statvfs(2) system call.

This function returns a "struct guestfs_statvfs *", or NULL if there was an error. The caller must call "guestfs_free_statvfs" after use.

guestfs_strings

  char **guestfs_strings (guestfs_h *g,
                 const char *path);
 
 

This runs the strings(1) command on a file and returns the list of printable strings found.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_strings_e

  char **guestfs_strings_e (guestfs_h *g,
                 const char *encoding,
                 const char *path);
 
 

This is like the "guestfs_strings" command, but allows you to specify the encoding of strings that are looked for in the source file "path".

Allowed encodings are:

s

Single 7-bit-byte characters like ASCII and the ASCII-compatible parts of ISO-8859-X (this is what "guestfs_strings" uses).

S

Single 8-bit-byte characters.

b

16-bit big endian strings such as those encoded in UTF-16BE or UCS-2BE.

l (lower case letter L)

16-bit little endian such as UTF-16LE and UCS-2LE. This is useful for examining binaries in Windows guests.

B

32-bit big endian such as UCS-4BE.

L

32-bit little endian such as UCS-4LE.

The returned strings are transcoded to UTF-8.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_swapoff_device

  int guestfs_swapoff_device (guestfs_h *g,
                 const char *device);
 
 

This command disables the libguestfs appliance swap device or partition named "device". See "guestfs_swapon_device".

This function returns 0 on success or -1 on error.

guestfs_swapoff_file

  int guestfs_swapoff_file (guestfs_h *g,
                 const char *file);
 
 

This command disables the libguestfs appliance swap on file.

This function returns 0 on success or -1 on error.

guestfs_swapoff_label

  int guestfs_swapoff_label (guestfs_h *g,
                 const char *label);
 
 

This command disables the libguestfs appliance swap on labeled swap partition.

This function returns 0 on success or -1 on error.

guestfs_swapoff_uuid

  int guestfs_swapoff_uuid (guestfs_h *g,
                 const char *uuid);
 
 

This command disables the libguestfs appliance swap partition with the given UUID.

This function returns 0 on success or -1 on error.

guestfs_swapon_device

  int guestfs_swapon_device (guestfs_h *g,
                 const char *device);
 
 

This command enables the libguestfs appliance to use the swap device or partition named "device". The increased memory is made available for all commands, for example those run using "guestfs_command" or "guestfs_sh".

Note that you should not swap to existing guest swap partitions unless you know what you are doing. They may contain hibernation information, or other information that the guest doesn't want you to trash. You also risk leaking information about the host to the guest this way. Instead, attach a new host device to the guest and swap on that.

This function returns 0 on success or -1 on error.

guestfs_swapon_file

  int guestfs_swapon_file (guestfs_h *g,
                 const char *file);
 
 

This command enables swap to a file. See "guestfs_swapon_device" for other notes.

This function returns 0 on success or -1 on error.

guestfs_swapon_label

  int guestfs_swapon_label (guestfs_h *g,
                 const char *label);
 
 

This command enables swap to a labeled swap partition. See "guestfs_swapon_device" for other notes.

This function returns 0 on success or -1 on error.

guestfs_swapon_uuid

  int guestfs_swapon_uuid (guestfs_h *g,
                 const char *uuid);
 
 

This command enables swap to a swap partition with the given UUID. See "guestfs_swapon_device" for other notes.

This function returns 0 on success or -1 on error.

guestfs_sync

  int guestfs_sync (guestfs_h *g);
 
 

This syncs the disk, so that any writes are flushed through to the underlying disk image.

You should always call this if you have modified a disk image, before closing the handle.

This function returns 0 on success or -1 on error.

guestfs_tail

  char **guestfs_tail (guestfs_h *g,
                 const char *path);
 
 

This command returns up to the last 10 lines of a file as a list of strings.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_tail_n

  char **guestfs_tail_n (guestfs_h *g,
                 int nrlines,
                 const char *path);
 
 

If the parameter "nrlines" is a positive number, this returns the last "nrlines" lines of the file "path".

If the parameter "nrlines" is a negative number, this returns lines from the file "path", starting with the "-nrlines"th line.

If the parameter "nrlines" is zero, this returns an empty list.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_tar_in

  int guestfs_tar_in (guestfs_h *g,
                 const char *tarfile,
                 const char *directory);
 
 

This command uploads and unpacks local file "tarfile" (an uncompressed tar file) into "directory".

To upload a compressed tarball, use "guestfs_tgz_in" or "guestfs_txz_in".

This function returns 0 on success or -1 on error.

guestfs_tar_out

  int guestfs_tar_out (guestfs_h *g,
                 const char *directory,
                 const char *tarfile);
 
 

This command packs the contents of "directory" and downloads it to local file "tarfile".

To download a compressed tarball, use "guestfs_tgz_out" or "guestfs_txz_out".

This function returns 0 on success or -1 on error.

guestfs_tgz_in

  int guestfs_tgz_in (guestfs_h *g,
                 const char *tarball,
                 const char *directory);
 
 

This command uploads and unpacks local file "tarball" (a gzip compressed tar file) into "directory".

To upload an uncompressed tarball, use "guestfs_tar_in".

This function returns 0 on success or -1 on error.

guestfs_tgz_out

  int guestfs_tgz_out (guestfs_h *g,
                 const char *directory,
                 const char *tarball);
 
 

This command packs the contents of "directory" and downloads it to local file "tarball".

To download an uncompressed tarball, use "guestfs_tar_out".

This function returns 0 on success or -1 on error.

guestfs_touch

  int guestfs_touch (guestfs_h *g,
                 const char *path);
 
 

Touch acts like the touch(1) command. It can be used to update the timestamps on a file, or, if the file does not exist, to create a new zero-length file.

This command only works on regular files, and will fail on other file types such as directories, symbolic links, block special etc.

This function returns 0 on success or -1 on error.

guestfs_truncate

  int guestfs_truncate (guestfs_h *g,
                 const char *path);
 
 

This command truncates "path" to a zero-length file. The file must exist already.

This function returns 0 on success or -1 on error.

guestfs_truncate_size

  int guestfs_truncate_size (guestfs_h *g,
                 const char *path,
                 int64_t size);
 
 

This command truncates "path" to size "size" bytes. The file must exist already.

If the current file size is less than "size" then the file is extended to the required size with zero bytes. This creates a sparse file (ie. disk blocks are not allocated for the file until you write to it). To create a non-sparse file of zeroes, use "guestfs_fallocate64" instead.

This function returns 0 on success or -1 on error.

guestfs_tune2fs_l

  char **guestfs_tune2fs_l (guestfs_h *g,
                 const char *device);
 
 

This returns the contents of the ext2, ext3 or ext4 filesystem superblock on "device".

It is the same as running "tune2fs -l device". See tune2fs(8) manpage for more details. The list of fields returned isn't clearly defined, and depends on both the version of "tune2fs" that libguestfs was built against, and the filesystem itself.

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

guestfs_txz_in

  int guestfs_txz_in (guestfs_h *g,
                 const char *tarball,
                 const char *directory);
 
 

This command uploads and unpacks local file "tarball" (an xz compressed tar file) into "directory".

This function returns 0 on success or -1 on error.

guestfs_txz_out

  int guestfs_txz_out (guestfs_h *g,
                 const char *directory,
                 const char *tarball);
 
 

This command packs the contents of "directory" and downloads it to local file "tarball" (as an xz compressed tar archive).

This function returns 0 on success or -1 on error.

guestfs_umask

  int guestfs_umask (guestfs_h *g,
                 int mask);
 
 

This function sets the mask used for creating new files and device nodes to "mask & 0777".

Typical umask values would be 022 which creates new files with permissions like ``-rw-r---r--'' or ``-rwxr-xr-x'', and 002 which creates new files with permissions like ``-rw-rw-r--'' or ``-rwxrwxr-x''.

The default umask is 022. This is important because it means that directories and device nodes will be created with 0644 or 0755 mode even if you specify 0777.

See also "guestfs_get_umask", umask(2), "guestfs_mknod", "guestfs_mkdir".

This call returns the previous umask.

On error this function returns -1.

guestfs_umount

  int guestfs_umount (guestfs_h *g,
                 const char *pathordevice);
 
 

This unmounts the given filesystem. The filesystem may be specified either by its mountpoint (path) or the device which contains the filesystem.

This function returns 0 on success or -1 on error.

guestfs_umount_all

  int guestfs_umount_all (guestfs_h *g);
 
 

This unmounts all mounted filesystems.

Some internal mounts are not unmounted by this call.

This function returns 0 on success or -1 on error.

guestfs_upload

  int guestfs_upload (guestfs_h *g,
                 const char *filename,
                 const char *remotefilename);
 
 

Upload local file "filename" to "remotefilename" on the filesystem.

"filename" can also be a named pipe.

See also "guestfs_download".

This function returns 0 on success or -1 on error.

guestfs_upload_offset

  int guestfs_upload_offset (guestfs_h *g,
                 const char *filename,
                 const char *remotefilename,
                 int64_t offset);
 
 

Upload local file "filename" to "remotefilename" on the filesystem.

"remotefilename" is overwritten starting at the byte "offset" specified. The intention is to overwrite parts of existing files or devices, although if a non-existant file is specified then it is created with a ``hole'' before "offset". The size of the data written is implicit in the size of the source "filename".

Note that there is no limit on the amount of data that can be uploaded with this call, unlike with "guestfs_pwrite", and this call always writes the full amount unless an error occurs.

See also "guestfs_upload", "guestfs_pwrite".

This function returns 0 on success or -1 on error.

guestfs_utimens

  int guestfs_utimens (guestfs_h *g,
                 const char *path,
                 int64_t atsecs,
                 int64_t atnsecs,
                 int64_t mtsecs,
                 int64_t mtnsecs);
 
 

This command sets the timestamps of a file with nanosecond precision.

"atsecs, atnsecs" are the last access time (atime) in secs and nanoseconds from the epoch.

"mtsecs, mtnsecs" are the last modification time (mtime) in secs and nanoseconds from the epoch.

If the *nsecs field contains the special value "-1" then the corresponding timestamp is set to the current time. (The *secs field is ignored in this case).

If the *nsecs field contains the special value "-2" then the corresponding timestamp is left unchanged. (The *secs field is ignored in this case).

This function returns 0 on success or -1 on error.

guestfs_version

  struct guestfs_version *guestfs_version (guestfs_h *g);
 
 

Return the libguestfs version number that the program is linked against.

Note that because of dynamic linking this is not necessarily the version of libguestfs that you compiled against. You can compile the program, and then at runtime dynamically link against a completely different "libguestfs.so" library.

This call was added in version 1.0.58. In previous versions of libguestfs there was no way to get the version number. From C code you can use dynamic linker functions to find out if this symbol exists (if it doesn't, then it's an earlier version).

The call returns a structure with four elements. The first three ("major", "minor" and "release") are numbers and correspond to the usual version triplet. The fourth element ("extra") is a string and is normally empty, but may be used for distro-specific information.

To construct the original version string: "$major.$minor.$release$extra"

See also: ``LIBGUESTFS VERSION NUMBERS'' in guestfs(3).

Note: Don't use this call to test for availability of features. In enterprise distributions we backport features from later versions into earlier versions, making this an unreliable way to test for features. Use "guestfs_available" instead.

This function returns a "struct guestfs_version *", or NULL if there was an error. The caller must call "guestfs_free_version" after use.

guestfs_vfs_label

  char *guestfs_vfs_label (guestfs_h *g,
                 const char *device);
 
 

This returns the filesystem label of the filesystem on "device".

If the filesystem is unlabeled, this returns the empty string.

To find a filesystem from the label, use "guestfs_findfs_label".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_vfs_type

  char *guestfs_vfs_type (guestfs_h *g,
                 const char *device);
 
 

This command gets the filesystem type corresponding to the filesystem on "device".

For most filesystems, the result is the name of the Linux VFS module which would be used to mount this filesystem if you mounted it without specifying the filesystem type. For example a string such as "ext3" or "ntfs".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_vfs_uuid

  char *guestfs_vfs_uuid (guestfs_h *g,
                 const char *device);
 
 

This returns the filesystem UUID of the filesystem on "device".

If the filesystem does not have a UUID, this returns the empty string.

To find a filesystem from the UUID, use "guestfs_findfs_uuid".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_vg_activate

  int guestfs_vg_activate (guestfs_h *g,
                 int activate,
                 char *const *volgroups);
 
 

This command activates or (if "activate" is false) deactivates all logical volumes in the listed volume groups "volgroups". If activated, then they are made known to the kernel, ie. they appear as "/dev/mapper" devices. If deactivated, then those devices disappear.

This command is the same as running "vgchange -a y|n volgroups..."

Note that if "volgroups" is an empty list then all volume groups are activated or deactivated.

This function returns 0 on success or -1 on error.

guestfs_vg_activate_all

  int guestfs_vg_activate_all (guestfs_h *g,
                 int activate);
 
 

This command activates or (if "activate" is false) deactivates all logical volumes in all volume groups. If activated, then they are made known to the kernel, ie. they appear as "/dev/mapper" devices. If deactivated, then those devices disappear.

This command is the same as running "vgchange -a y|n"

This function returns 0 on success or -1 on error.

guestfs_vgcreate

  int guestfs_vgcreate (guestfs_h *g,
                 const char *volgroup,
                 char *const *physvols);
 
 

This creates an LVM volume group called "volgroup" from the non-empty list of physical volumes "physvols".

This function returns 0 on success or -1 on error.

guestfs_vglvuuids

  char **guestfs_vglvuuids (guestfs_h *g,
                 const char *vgname);
 
 

Given a VG called "vgname", this returns the UUIDs of all the logical volumes created in this volume group.

You can use this along with "guestfs_lvs" and "guestfs_lvuuid" calls to associate logical volumes and volume groups.

See also "guestfs_vgpvuuids".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_vgpvuuids

  char **guestfs_vgpvuuids (guestfs_h *g,
                 const char *vgname);
 
 

Given a VG called "vgname", this returns the UUIDs of all the physical volumes that this volume group resides on.

You can use this along with "guestfs_pvs" and "guestfs_pvuuid" calls to associate physical volumes and volume groups.

See also "guestfs_vglvuuids".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_vgremove

  int guestfs_vgremove (guestfs_h *g,
                 const char *vgname);
 
 

Remove an LVM volume group "vgname", (for example "VG").

This also forcibly removes all logical volumes in the volume group (if any).

This function returns 0 on success or -1 on error.

guestfs_vgrename

  int guestfs_vgrename (guestfs_h *g,
                 const char *volgroup,
                 const char *newvolgroup);
 
 

Rename a volume group "volgroup" with the new name "newvolgroup".

This function returns 0 on success or -1 on error.

guestfs_vgs

  char **guestfs_vgs (guestfs_h *g);
 
 

List all the volumes groups detected. This is the equivalent of the vgs(8) command.

This returns a list of just the volume group names that were detected (eg. "VolGroup00").

See also "guestfs_vgs_full".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_vgs_full

  struct guestfs_lvm_vg_list *guestfs_vgs_full (guestfs_h *g);
 
 

List all the volumes groups detected. This is the equivalent of the vgs(8) command. The ``full'' version includes all fields.

This function returns a "struct guestfs_lvm_vg_list *" (see <guestfs-structs.h>), or NULL if there was an error. The caller must call "guestfs_free_lvm_vg_list" after use.

guestfs_vgscan

  int guestfs_vgscan (guestfs_h *g);
 
 

This rescans all block devices and rebuilds the list of LVM physical volumes, volume groups and logical volumes.

This function returns 0 on success or -1 on error.

guestfs_vguuid

  char *guestfs_vguuid (guestfs_h *g,
                 const char *vgname);
 
 

This command returns the UUID of the LVM VG named "vgname".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_wait_ready

  int guestfs_wait_ready (guestfs_h *g);
 
 

This function is a no op.

In versions of the API < 1.0.71 you had to call this function just after calling "guestfs_launch" to wait for the launch to complete. However this is no longer necessary because "guestfs_launch" now does the waiting.

If you see any calls to this function in code then you can just remove them, unless you want to retain compatibility with older versions of the API.

This function returns 0 on success or -1 on error.

guestfs_wc_c

  int guestfs_wc_c (guestfs_h *g,
                 const char *path);
 
 

This command counts the characters in a file, using the "wc -c" external command.

On error this function returns -1.

guestfs_wc_l

  int guestfs_wc_l (guestfs_h *g,
                 const char *path);
 
 

This command counts the lines in a file, using the "wc -l" external command.

On error this function returns -1.

guestfs_wc_w

  int guestfs_wc_w (guestfs_h *g,
                 const char *path);
 
 

This command counts the words in a file, using the "wc -w" external command.

On error this function returns -1.

guestfs_write

  int guestfs_write (guestfs_h *g,
                 const char *path,
                 const char *content,
                 size_t content_size);
 
 

This call creates a file called "path". The content of the file is the string "content" (which can contain any 8 bit data).

This function returns 0 on success or -1 on error.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_write_file

  int guestfs_write_file (guestfs_h *g,
                 const char *path,
                 const char *content,
                 int size);
 
 

This call creates a file called "path". The contents of the file is the string "content" (which can contain any 8 bit data), with length "size".

As a special case, if "size" is 0 then the length is calculated using "strlen" (so in this case the content cannot contain embedded ASCII NULs).

NB. Owing to a bug, writing content containing ASCII NUL characters does not work, even if the length is specified.

This function returns 0 on success or -1 on error.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

This function is deprecated. In new code, use the "write" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

guestfs_zegrep

  char **guestfs_zegrep (guestfs_h *g,
                 const char *regex,
                 const char *path);
 
 

This calls the external "zegrep" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_zegrepi

  char **guestfs_zegrepi (guestfs_h *g,
                 const char *regex,
                 const char *path);
 
 

This calls the external "zegrep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_zero

  int guestfs_zero (guestfs_h *g,
                 const char *device);
 
 

This command writes zeroes over the first few blocks of "device".

How many blocks are zeroed isn't specified (but it's not enough to securely wipe the device). It should be sufficient to remove any partition tables, filesystem superblocks and so on.

See also: "guestfs_zero_device", "guestfs_scrub_device".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress callback. See ``guestfs_set_progress_callback'' in guestfs(3).

guestfs_zero_device

  int guestfs_zero_device (guestfs_h *g,
                 const char *device);
 
 

This command writes zeroes over the entire "device". Compare with "guestfs_zero" which just zeroes the first few blocks of a device.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress callback. See ``guestfs_set_progress_callback'' in guestfs(3).

This command is dangerous. Without careful use you can easily destroy all your data.

guestfs_zerofree

  int guestfs_zerofree (guestfs_h *g,
                 const char *device);
 
 

This runs the zerofree program on "device". This program claims to zero unused inodes and disk blocks on an ext2/3 filesystem, thus making it possible to compress the filesystem more effectively.

You should not run this program if the filesystem is mounted.

It is possible that using this program can damage the filesystem or data on the filesystem.

This function returns 0 on success or -1 on error.

guestfs_zfgrep

  char **guestfs_zfgrep (guestfs_h *g,
                 const char *pattern,
                 const char *path);
 
 

This calls the external "zfgrep" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_zfgrepi

  char **guestfs_zfgrepi (guestfs_h *g,
                 const char *pattern,
                 const char *path);
 
 

This calls the external "zfgrep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_zfile

  char *guestfs_zfile (guestfs_h *g,
                 const char *meth,
                 const char *path);
 
 

This command runs "file" after first decompressing "path" using "method".

"method" must be one of "gzip", "compress" or "bzip2".

Since 1.0.63, use "guestfs_file" instead which can now process compressed files.

This function returns a string, or NULL on error. The caller must free the returned string after use.

This function is deprecated. In new code, use the "file" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

guestfs_zgrep

  char **guestfs_zgrep (guestfs_h *g,
                 const char *regex,
                 const char *path);
 
 

This calls the external "zgrep" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

guestfs_zgrepi

  char **guestfs_zgrepi (guestfs_h *g,
                 const char *regex,
                 const char *path);
 
 

This calls the external "zgrep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See ``PROTOCOL LIMITS'' in guestfs(3).

STRUCTURES

guestfs_int_bool

  struct guestfs_int_bool {
    int32_t i;
    int32_t b;
  };
  
  struct guestfs_int_bool_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_int_bool *val; /* Elements. */
  };
  
  void guestfs_free_int_bool (struct guestfs_free_int_bool *);
  void guestfs_free_int_bool_list (struct guestfs_free_int_bool_list *);
 
 

guestfs_lvm_pv

  struct guestfs_lvm_pv {
    char *pv_name;
    /* The next field is NOT nul-terminated, be careful when printing it: */
    char pv_uuid[32];
    char *pv_fmt;
    uint64_t pv_size;
    uint64_t dev_size;
    uint64_t pv_free;
    uint64_t pv_used;
    char *pv_attr;
    int64_t pv_pe_count;
    int64_t pv_pe_alloc_count;
    char *pv_tags;
    uint64_t pe_start;
    int64_t pv_mda_count;
    uint64_t pv_mda_free;
  };
  
  struct guestfs_lvm_pv_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_lvm_pv *val; /* Elements. */
  };
  
  void guestfs_free_lvm_pv (struct guestfs_free_lvm_pv *);
  void guestfs_free_lvm_pv_list (struct guestfs_free_lvm_pv_list *);
 
 

guestfs_lvm_vg

  struct guestfs_lvm_vg {
    char *vg_name;
    /* The next field is NOT nul-terminated, be careful when printing it: */
    char vg_uuid[32];
    char *vg_fmt;
    char *vg_attr;
    uint64_t vg_size;
    uint64_t vg_free;
    char *vg_sysid;
    uint64_t vg_extent_size;
    int64_t vg_extent_count;
    int64_t vg_free_count;
    int64_t max_lv;
    int64_t max_pv;
    int64_t pv_count;
    int64_t lv_count;
    int64_t snap_count;
    int64_t vg_seqno;
    char *vg_tags;
    int64_t vg_mda_count;
    uint64_t vg_mda_free;
  };
  
  struct guestfs_lvm_vg_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_lvm_vg *val; /* Elements. */
  };
  
  void guestfs_free_lvm_vg (struct guestfs_free_lvm_vg *);
  void guestfs_free_lvm_vg_list (struct guestfs_free_lvm_vg_list *);
 
 

guestfs_lvm_lv

  struct guestfs_lvm_lv {
    char *lv_name;
    /* The next field is NOT nul-terminated, be careful when printing it: */
    char lv_uuid[32];
    char *lv_attr;
    int64_t lv_major;
    int64_t lv_minor;
    int64_t lv_kernel_major;
    int64_t lv_kernel_minor;
    uint64_t lv_size;
    int64_t seg_count;
    char *origin;
    /* The next field is [0..100] or -1 meaning 'not present': */
    float snap_percent;
    /* The next field is [0..100] or -1 meaning 'not present': */
    float copy_percent;
    char *move_pv;
    char *lv_tags;
    char *mirror_log;
    char *modules;
  };
  
  struct guestfs_lvm_lv_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_lvm_lv *val; /* Elements. */
  };
  
  void guestfs_free_lvm_lv (struct guestfs_free_lvm_lv *);
  void guestfs_free_lvm_lv_list (struct guestfs_free_lvm_lv_list *);
 
 

guestfs_stat

  struct guestfs_stat {
    int64_t dev;
    int64_t ino;
    int64_t mode;
    int64_t nlink;
    int64_t uid;
    int64_t gid;
    int64_t rdev;
    int64_t size;
    int64_t blksize;
    int64_t blocks;
    int64_t atime;
    int64_t mtime;
    int64_t ctime;
  };
  
  struct guestfs_stat_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_stat *val; /* Elements. */
  };
  
  void guestfs_free_stat (struct guestfs_free_stat *);
  void guestfs_free_stat_list (struct guestfs_free_stat_list *);
 
 

guestfs_statvfs

  struct guestfs_statvfs {
    int64_t bsize;
    int64_t frsize;
    int64_t blocks;
    int64_t bfree;
    int64_t bavail;
    int64_t files;
    int64_t ffree;
    int64_t favail;
    int64_t fsid;
    int64_t flag;
    int64_t namemax;
  };
  
  struct guestfs_statvfs_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_statvfs *val; /* Elements. */
  };
  
  void guestfs_free_statvfs (struct guestfs_free_statvfs *);
  void guestfs_free_statvfs_list (struct guestfs_free_statvfs_list *);
 
 

guestfs_dirent

  struct guestfs_dirent {
    int64_t ino;
    char ftyp;
    char *name;
  };
  
  struct guestfs_dirent_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_dirent *val; /* Elements. */
  };
  
  void guestfs_free_dirent (struct guestfs_free_dirent *);
  void guestfs_free_dirent_list (struct guestfs_free_dirent_list *);
 
 

guestfs_version

  struct guestfs_version {
    int64_t major;
    int64_t minor;
    int64_t release;
    char *extra;
  };
  
  struct guestfs_version_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_version *val; /* Elements. */
  };
  
  void guestfs_free_version (struct guestfs_free_version *);
  void guestfs_free_version_list (struct guestfs_free_version_list *);
 
 

guestfs_xattr

  struct guestfs_xattr {
    char *attrname;
    /* The next two fields describe a byte array. */
    uint32_t attrval_len;
    char *attrval;
  };
  
  struct guestfs_xattr_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_xattr *val; /* Elements. */
  };
  
  void guestfs_free_xattr (struct guestfs_free_xattr *);
  void guestfs_free_xattr_list (struct guestfs_free_xattr_list *);
 
 

guestfs_inotify_event

  struct guestfs_inotify_event {
    int64_t in_wd;
    uint32_t in_mask;
    uint32_t in_cookie;
    char *in_name;
  };
  
  struct guestfs_inotify_event_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_inotify_event *val; /* Elements. */
  };
  
  void guestfs_free_inotify_event (struct guestfs_free_inotify_event *);
  void guestfs_free_inotify_event_list (struct guestfs_free_inotify_event_list *);
 
 

guestfs_partition

  struct guestfs_partition {
    int32_t part_num;
    uint64_t part_start;
    uint64_t part_end;
    uint64_t part_size;
  };
  
  struct guestfs_partition_list {
    uint32_t len; /* Number of elements in list. */
    struct guestfs_partition *val; /* Elements. */
  };
  
  void guestfs_free_partition (struct guestfs_free_partition *);
  void guestfs_free_partition_list (struct guestfs_free_partition_list *);
 
 

AVAILABILITY

GROUPS OF FUNCTIONALITY IN THE APPLIANCE

Using ``guestfs_available'' you can test availability of the following groups of functions. This test queries the appliance to see if the appliance you are currently using supports the functionality.

augeas

The following functions: ``guestfs_aug_clear'' ``guestfs_aug_close'' ``guestfs_aug_defnode'' ``guestfs_aug_defvar'' ``guestfs_aug_get'' ``guestfs_aug_init'' ``guestfs_aug_insert'' ``guestfs_aug_load'' ``guestfs_aug_ls'' ``guestfs_aug_match'' ``guestfs_aug_mv'' ``guestfs_aug_rm'' ``guestfs_aug_save'' ``guestfs_aug_set''

inotify

The following functions: ``guestfs_inotify_add_watch'' ``guestfs_inotify_close'' ``guestfs_inotify_files'' ``guestfs_inotify_init'' ``guestfs_inotify_read'' ``guestfs_inotify_rm_watch''

linuxfsuuid

The following functions: ``guestfs_mke2fs_JU'' ``guestfs_mke2journal_U'' ``guestfs_mkswap_U'' ``guestfs_swapoff_uuid'' ``guestfs_swapon_uuid''

linuxmodules

The following functions: ``guestfs_modprobe''

linuxxattrs

The following functions: ``guestfs_getxattrs'' ``guestfs_lgetxattrs'' ``guestfs_lremovexattr'' ``guestfs_lsetxattr'' ``guestfs_lxattrlist'' ``guestfs_removexattr'' ``guestfs_setxattr''

luks

The following functions: ``guestfs_luks_add_key'' ``guestfs_luks_close'' ``guestfs_luks_format'' ``guestfs_luks_format_cipher'' ``guestfs_luks_kill_slot'' ``guestfs_luks_open'' ``guestfs_luks_open_ro''

lvm2

The following functions: ``guestfs_is_lv'' ``guestfs_lvcreate'' ``guestfs_lvm_remove_all'' ``guestfs_lvm_set_filter'' ``guestfs_lvremove'' ``guestfs_lvresize'' ``guestfs_lvresize_free'' ``guestfs_lvs'' ``guestfs_lvs_full'' ``guestfs_pvcreate'' ``guestfs_pvremove'' ``guestfs_pvresize'' ``guestfs_pvresize_size'' ``guestfs_pvs'' ``guestfs_pvs_full'' ``guestfs_vg_activate'' ``guestfs_vg_activate_all'' ``guestfs_vgcreate'' ``guestfs_vgremove'' ``guestfs_vgs'' ``guestfs_vgs_full''

mknod

The following functions: ``guestfs_mkfifo'' ``guestfs_mknod'' ``guestfs_mknod_b'' ``guestfs_mknod_c''

ntfs3g

The following functions: ``guestfs_ntfs_3g_probe''

ntfsprogs

The following functions: ``guestfs_ntfsresize'' ``guestfs_ntfsresize_size''

realpath

The following functions: ``guestfs_realpath''

scrub

The following functions: ``guestfs_scrub_device'' ``guestfs_scrub_file'' ``guestfs_scrub_freespace''

selinux

The following functions: ``guestfs_getcon'' ``guestfs_setcon''

xz

The following functions: ``guestfs_txz_in'' ``guestfs_txz_out''

zerofree

The following functions: ``guestfs_zerofree''

GUESTFISH supported COMMAND

In guestfish(3) there is a handy interactive command "supported" which prints out the available groups and whether they are supported by this build of libguestfs. Note however that you have to do "run" first.

SINGLE CALLS AT COMPILE TIME

Since version 1.5.8, "<guestfs.h>" defines symbols for each C API function, such as:

  #define LIBGUESTFS_HAVE_DD 1
 
 

if ``guestfs_dd'' is available.

Before version 1.5.8, if you needed to test whether a single libguestfs function is available at compile time, we recommended using build tools such as autoconf or cmake. For example in autotools you could use:

  AC_CHECK_LIB([guestfs],[guestfs_create])
  AC_CHECK_FUNCS([guestfs_dd])
 
 

which would result in "HAVE_GUESTFS_DD" being either defined or not defined in your program.

SINGLE CALLS AT RUN TIME

Testing at compile time doesn't guarantee that a function really exists in the library. The reason is that you might be dynamically linked against a previous libguestfs.so (dynamic library) which doesn't have the call. This situation unfortunately results in a segmentation fault, which is a shortcoming of the C dynamic linking system itself.

You can use dlopen(3) to test if a function is available at run time, as in this example program (note that you still need the compile time check as well):

  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <dlfcn.h>
  #include <guestfs.h>
  
  main ()
  {
  #ifdef LIBGUESTFS_HAVE_DD
    void *dl;
    int has_function;
  
    /* Test if the function guestfs_dd is really available. */
    dl = dlopen (NULL, RTLD_LAZY);
    if (!dl) {
      fprintf (stderr, "dlopen: %s\n", dlerror ());
      exit (EXIT_FAILURE);
    }
    has_function = dlsym (dl, "guestfs_dd") != NULL;
    dlclose (dl);
  
    if (!has_function)
      printf ("this libguestfs.so does NOT have guestfs_dd function\n");
    else {
      printf ("this libguestfs.so has guestfs_dd function\n");
      /* Now it's safe to call
      guestfs_dd (g, "foo", "bar");
      */
    }
  #else
    printf ("guestfs_dd function was not found at compile time\n");
  #endif
   }
 
 

You may think the above is an awful lot of hassle, and it is. There are other ways outside of the C linking system to ensure that this kind of incompatibility never arises, such as using package versioning:

  Requires: libguestfs >= 1.0.80
 
 

ARCHITECTURE

Internally, libguestfs is implemented by running an appliance (a special type of small virtual machine) using qemu(1). Qemu runs as a child process of the main program.

   ___________________
  /                   \
  | main program      |
  |                   |
  |                   |           child process / appliance
  |                   |           __________________________
  |                   |          / qemu                     \
  +-------------------+   RPC    |      +-----------------+ |
  | libguestfs     <--------------------> guestfsd        | |
  |                   |          |      +-----------------+ |
  \___________________/          |      | Linux kernel    | |
                                 |      +--^--------------+ |
                                 \_________|________________/
                                           |
                                    _______v______
                                   /              \
                                   | Device or    |
                                   | disk image   |
                                   \______________/
 
 

The library, linked to the main program, creates the child process and hence the appliance in the ``guestfs_launch'' function.

Inside the appliance is a Linux kernel and a complete stack of userspace tools (such as LVM and ext2 programs) and a small controlling daemon called ``guestfsd''. The library talks to ``guestfsd'' using remote procedure calls (RPC). There is a mostly one-to-one correspondence between libguestfs API calls and RPC calls to the daemon. Lastly the disk image(s) are attached to the qemu process which translates device access by the appliance's Linux kernel into accesses to the image.

A common misunderstanding is that the appliance ``is'' the virtual machine. Although the disk image you are attached to might also be used by some virtual machine, libguestfs doesn't know or care about this. (But you will care if both libguestfs's qemu process and your virtual machine are trying to update the disk image at the same time, since these usually results in massive disk corruption).

STATE MACHINE

libguestfs uses a state machine to model the child process:

                          |
                     guestfs_create
                          |
                          |
                      ____V_____
                     /          \
                     |  CONFIG  |
                     \__________/
                      ^ ^   ^  \
                     /  |    \  \ guestfs_launch
                    /   |    _\__V______
                   /    |   /           \
                  /     |   | LAUNCHING |
                 /      |   \___________/
                /       |       /
               /        |  guestfs_launch
              /         |     /
     ______  /        __|____V
    /      \ ------> /        \
    | BUSY |         | READY  |
    \______/ <------ \________/
 
 

The normal transitions are (1) CONFIG (when the handle is created, but there is no child process), (2) LAUNCHING (when the child process is booting up), (3) alternating between READY and BUSY as commands are issued to, and carried out by, the child process.

The guest may be killed by ``guestfs_kill_subprocess'', or may die asynchronously at any time (eg. due to some internal error), and that causes the state to transition back to CONFIG.

Configuration commands for qemu such as ``guestfs_add_drive'' can only be issued when in the CONFIG state.

The API offers one call that goes from CONFIG through LAUNCHING to READY. ``guestfs_launch'' blocks until the child process is READY to accept commands (or until some failure or timeout). ``guestfs_launch'' internally moves the state from CONFIG to LAUNCHING while it is running.

API actions such as ``guestfs_mount'' can only be issued when in the READY state. These API calls block waiting for the command to be carried out (ie. the state to transition to BUSY and then back to READY). There are no non-blocking versions, and no way to issue more than one command per handle at the same time.

Finally, the child process sends asynchronous messages back to the main program, such as kernel log messages. You can register a callback to receive these messages.

SETTING CALLBACKS TO HANDLE EVENTS

The child process generates events in some situations. Current events include: receiving a log message, the child process exits.

Use the "guestfs_set_*_callback" functions to set a callback for different types of events.

Only one callback of each type can be registered for each handle. Calling "guestfs_set_*_callback" again overwrites the previous callback of that type. Cancel all callbacks of this type by calling this function with "cb" set to "NULL".

guestfs_set_log_message_callback

  typedef void (*guestfs_log_message_cb) (guestfs_h *g, void *opaque,
                                          char *buf, int len);
  void guestfs_set_log_message_callback (guestfs_h *g,
                                         guestfs_log_message_cb cb,
                                         void *opaque);
 
 

The callback function "cb" will be called whenever qemu or the guest writes anything to the console.

Use this function to capture kernel messages and similar.

Normally there is no log message handler, and log messages are just discarded.

guestfs_set_subprocess_quit_callback

  typedef void (*guestfs_subprocess_quit_cb) (guestfs_h *g, void *opaque);
  void guestfs_set_subprocess_quit_callback (guestfs_h *g,
                                             guestfs_subprocess_quit_cb cb,
                                             void *opaque);
 
 

The callback function "cb" will be called when the child process quits, either asynchronously or if killed by ``guestfs_kill_subprocess''. (This corresponds to a transition from any state to the CONFIG state).

guestfs_set_launch_done_callback

  typedef void (*guestfs_launch_done_cb) (guestfs_h *g, void *opaque);
  void guestfs_set_launch_done_callback (guestfs_h *g,
                                         guestfs_launch_done_cb cb,
                                         void *opaque);
 
 

The callback function "cb" will be called when the child process becomes ready first time after it has been launched. (This corresponds to a transition from LAUNCHING to the READY state).

guestfs_set_close_callback

  typedef void (*guestfs_close_cb) (guestfs_h *g, void *opaque);
  void guestfs_set_close_callback (guestfs_h *g,
                                   guestfs_close_cb cb,
                                   void *opaque);
 
 

The callback function "cb" will be called while the handle is being closed (synchronously from ``guestfs_close'').

Note that libguestfs installs an atexit(3) handler to try to clean up handles that are open when the program exits. This means that this callback might be called indirectly from exit(3), which can cause unexpected problems in higher-level languages (eg. if your HLL interpreter has already been cleaned up by the time this is called, and if your callback then jumps into some HLL function).

guestfs_set_progress_callback

  typedef void (*guestfs_progress_cb) (guestfs_h *g, void *opaque,
                                       int proc_nr, int serial,
                                       uint64_t position, uint64_t total);
  void guestfs_set_progress_callback (guestfs_h *g,
                                      guestfs_progress_cb cb,
                                      void *opaque);
 
 

Some long-running operations can generate progress messages. If this callback is registered, then it will be called each time a progress message is generated (usually two seconds after the operation started, and three times per second thereafter until it completes, although the frequency may change in future versions).

The callback receives two numbers: "position" and "total". The units of "total" are not defined, although for some operations "total" may relate in some way to the amount of data to be transferred (eg. in bytes or megabytes), and "position" may be the portion which has been transferred.

The only defined and stable parts of the API are:

*

The callback can display to the user some type of progress bar or indicator which shows the ratio of "position":"total".

*

0 <= "position" <= "total"

*

If any progress notification is sent during a call, then a final progress notification is always sent when "position" = "total".

This is to simplify caller code, so callers can easily set the progress indicator to ``100%'' at the end of the operation, without requiring special code to detect this case.

The callback also receives the procedure number and serial number of the call. These are only useful for debugging protocol issues, and the callback can normally ignore them. The callback may want to print these numbers in error messages or debugging messages.

PRIVATE DATA AREA

You can attach named pieces of private data to the libguestfs handle, and fetch them by name for the lifetime of the handle. This is called the private data area and is only available from the C API.

To attach a named piece of data, use the following call:

  void guestfs_set_private (guestfs_h *g, const char *key, void *data);
 
 

"key" is the name to associate with this data, and "data" is an arbitrary pointer (which can be "NULL"). Any previous item with the same name is overwritten.

You can use any "key" you want, but names beginning with an underscore character are reserved for internal libguestfs purposes (for implementing language bindings). It is recommended to prefix the name with some unique string to avoid collisions with other users.

To retrieve the pointer, use:

  void *guestfs_get_private (guestfs_h *g, const char *key);
 
 

This function returns "NULL" if either no data is found associated with "key", or if the user previously set the "key"'s "data" pointer to "NULL".

Libguestfs does not try to look at or interpret the "data" pointer in any way. As far as libguestfs is concerned, it need not be a valid pointer at all. In particular, libguestfs does not try to free the data when the handle is closed. If the data must be freed, then the caller must either free it before calling ``guestfs_close'' or must set up a close callback to do it (see ``guestfs_set_close_callback'', and note that only one callback can be registered for a handle).

The private data area is implemented using a hash table, and should be reasonably efficient for moderate numbers of keys.

BLOCK DEVICE NAMING

In the kernel there is now quite a profusion of schemata for naming block devices (in this context, by block device I mean a physical or virtual hard drive). The original Linux IDE driver used names starting with "/dev/hd*". SCSI devices have historically used a different naming scheme, "/dev/sd*". When the Linux kernel libata driver became a popular replacement for the old IDE driver (particularly for SATA devices) those devices also used the "/dev/sd*" scheme. Additionally we now have virtual machines with paravirtualized drivers. This has created several different naming systems, such as "/dev/vd*" for virtio disks and "/dev/xvd*" for Xen PV disks.

As discussed above, libguestfs uses a qemu appliance running an embedded Linux kernel to access block devices. We can run a variety of appliances based on a variety of Linux kernels.

This causes a problem for libguestfs because many API calls use device or partition names. Working scripts and the recipe (example) scripts that we make available over the internet could fail if the naming scheme changes.

Therefore libguestfs defines "/dev/sd*" as the standard naming scheme. Internally "/dev/sd*" names are translated, if necessary, to other names as required. For example, under RHEL 5 which uses the "/dev/hd*" scheme, any device parameter "/dev/sda2" is translated to "/dev/hda2" transparently.

Note that this only applies to parameters. The ``guestfs_list_devices'', ``guestfs_list_partitions'' and similar calls return the true names of the devices and partitions as known to the appliance.

ALGORITHM FOR BLOCK DEVICE NAME TRANSLATION

Usually this translation is transparent. However in some (very rare) cases you may need to know the exact algorithm. Such cases include where you use ``guestfs_config'' to add a mixture of virtio and IDE devices to the qemu-based appliance, so have a mixture of "/dev/sd*" and "/dev/vd*" devices.

The algorithm is applied only to parameters which are known to be either device or partition names. Return values from functions such as ``guestfs_list_devices'' are never changed.

*

Is the string a parameter which is a device or partition name?

*

Does the string begin with "/dev/sd"?

*

Does the named device exist? If so, we use that device. However if not then we continue with this algorithm.

*

Replace initial "/dev/sd" string with "/dev/hd".

For example, change "/dev/sda2" to "/dev/hda2".

If that named device exists, use it. If not, continue.

*

Replace initial "/dev/sd" string with "/dev/vd".

If that named device exists, use it. If not, return an error.

PORTABILITY CONCERNS

Although the standard naming scheme and automatic translation is useful for simple programs and guestfish scripts, for larger programs it is best not to rely on this mechanism.

Where possible for maximum future portability programs using libguestfs should use these future-proof techniques:

*

Use ``guestfs_list_devices'' or ``guestfs_list_partitions'' to list actual device names, and then use those names directly.

Since those device names exist by definition, they will never be translated.

*

Use higher level ways to identify filesystems, such as LVM names, UUIDs and filesystem labels.

INTERNALS

COMMUNICATION PROTOCOL

Don't rely on using this protocol directly. This section documents how it currently works, but it may change at any time.

The protocol used to talk between the library and the daemon running inside the qemu virtual machine is a simple RPC mechanism built on top of XDR (RFC 1014, RFC 1832, RFC 4506).

The detailed format of structures is in "src/guestfs_protocol.x" (note: this file is automatically generated).

There are two broad cases, ordinary functions that don't have any "FileIn" and "FileOut" parameters, which are handled with very simple request/reply messages. Then there are functions that have any "FileIn" or "FileOut" parameters, which use the same request and reply messages, but they may also be followed by files sent using a chunked encoding.

ORDINARY FUNCTIONS (NO FILEIN/FILEOUT PARAMS)

For ordinary functions, the request message is:

  total length (header + arguments,
       but not including the length word itself)
  struct guestfs_message_header (encoded as XDR)
  struct guestfs_<foo>_args (encoded as XDR)
 
 

The total length field allows the daemon to allocate a fixed size buffer into which it slurps the rest of the message. As a result, the total length is limited to "GUESTFS_MESSAGE_MAX" bytes (currently 4MB), which means the effective size of any request is limited to somewhere under this size.

Note also that many functions don't take any arguments, in which case the "guestfs_foo_args" is completely omitted.

The header contains the procedure number ("guestfs_proc") which is how the receiver knows what type of args structure to expect, or none at all.

The reply message for ordinary functions is:

  total length (header + ret,
       but not including the length word itself)
  struct guestfs_message_header (encoded as XDR)
  struct guestfs_<foo>_ret (encoded as XDR)
 
 

As above the "guestfs_foo_ret" structure may be completely omitted for functions that return no formal return values.

As above the total length of the reply is limited to "GUESTFS_MESSAGE_MAX".

In the case of an error, a flag is set in the header, and the reply message is slightly changed:

  total length (header + error,
       but not including the length word itself)
  struct guestfs_message_header (encoded as XDR)
  struct guestfs_message_error (encoded as XDR)
 
 

The "guestfs_message_error" structure contains the error message as a string.

FUNCTIONS THAT HAVE FILEIN PARAMETERS

A "FileIn" parameter indicates that we transfer a file into the guest. The normal request message is sent (see above). However this is followed by a sequence of file chunks.

  total length (header + arguments,
       but not including the length word itself,
       and not including the chunks)
  struct guestfs_message_header (encoded as XDR)
  struct guestfs_<foo>_args (encoded as XDR)
  sequence of chunks for FileIn param #0
  sequence of chunks for FileIn param #1 etc.
 
 

The ``sequence of chunks'' is:

  length of chunk (not including length word itself)
  struct guestfs_chunk (encoded as XDR)
  length of chunk
  struct guestfs_chunk (encoded as XDR)
    ...
  length of chunk
  struct guestfs_chunk (with data.data_len == 0)
 
 

The final chunk has the "data_len" field set to zero. Additionally a flag is set in the final chunk to indicate either successful completion or early cancellation.

At time of writing there are no functions that have more than one FileIn parameter. However this is (theoretically) supported, by sending the sequence of chunks for each FileIn parameter one after another (from left to right).

Both the library (sender) and the daemon (receiver) may cancel the transfer. The library does this by sending a chunk with a special flag set to indicate cancellation. When the daemon sees this, it cancels the whole RPC, does not send any reply, and goes back to reading the next request.

The daemon may also cancel. It does this by writing a special word "GUESTFS_CANCEL_FLAG" to the socket. The library listens for this during the transfer, and if it gets it, it will cancel the transfer (it sends a cancel chunk). The special word is chosen so that even if cancellation happens right at the end of the transfer (after the library has finished writing and has started listening for the reply), the ``spurious'' cancel flag will not be confused with the reply message.

This protocol allows the transfer of arbitrary sized files (no 32 bit limit), and also files where the size is not known in advance (eg. from pipes or sockets). However the chunks are rather small ("GUESTFS_MAX_CHUNK_SIZE"), so that neither the library nor the daemon need to keep much in memory.

FUNCTIONS THAT HAVE FILEOUT PARAMETERS

The protocol for FileOut parameters is exactly the same as for FileIn parameters, but with the roles of daemon and library reversed.

  total length (header + ret,
       but not including the length word itself,
       and not including the chunks)
  struct guestfs_message_header (encoded as XDR)
  struct guestfs_<foo>_ret (encoded as XDR)
  sequence of chunks for FileOut param #0
  sequence of chunks for FileOut param #1 etc.
 
 

INITIAL MESSAGE

When the daemon launches it sends an initial word ("GUESTFS_LAUNCH_FLAG") which indicates that the guest and daemon is alive. This is what ``guestfs_launch'' waits for.

PROGRESS NOTIFICATION MESSAGES

The daemon may send progress notification messages at any time. These are distinguished by the normal length word being replaced by "GUESTFS_PROGRESS_FLAG", followed by a fixed size progress message.

The library turns them into progress callbacks (see "guestfs_set_progress_callback") if there is a callback registered, or discards them if not.

The daemon self-limits the frequency of progress messages it sends (see "daemon/proto.c:notify_progress"). Not all calls generate progress messages.

MULTIPLE HANDLES AND MULTIPLE THREADS

All high-level libguestfs actions are synchronous. If you want to use libguestfs asynchronously then you must create a thread.

Only use the handle from a single thread. Either use the handle exclusively from one thread, or provide your own mutex so that two threads cannot issue calls on the same handle at the same time.

See the graphical program guestfs-browser for one possible architecture for multithreaded programs using libvirt and libguestfs.

QEMU WRAPPERS

If you want to compile your own qemu, run qemu from a non-standard location, or pass extra arguments to qemu, then you can write a shell-script wrapper around qemu.

There is one important rule to remember: you must "exec qemu" as the last command in the shell script (so that qemu replaces the shell and becomes the direct child of the libguestfs-using program). If you don't do this, then the qemu process won't be cleaned up correctly.

Here is an example of a wrapper, where I have built my own copy of qemu from source:

  #!/bin/sh -
  qemudir=/home/rjones/d/qemu
  exec $qemudir/x86_64-softmmu/qemu-system-x86_64 -L $qemudir/pc-bios "$@"
 
 

Save this script as "/tmp/qemu.wrapper" (or wherever), "chmod +x", and then use it by setting the LIBGUESTFS_QEMU environment variable. For example:

  LIBGUESTFS_QEMU=/tmp/qemu.wrapper guestfish
 
 

Note that libguestfs also calls qemu with the -help and -version options in order to determine features.

LIBGUESTFS VERSION NUMBERS

Since April 2010, libguestfs has started to make separate development and stable releases, along with corresponding branches in our git repository. These separate releases can be identified by version number:

                  even numbers for stable: 1.2.x, 1.4.x, ...
        .-------- odd numbers for development: 1.3.x, 1.5.x, ...
        |
        v
  1  .  3  .  5
  ^           ^
  |           |
  |           `-------- sub-version
  |
  `------ always '1' because we don't change the ABI
 
 

Thus ``1.3.5'' is the 5th update to the development branch ``1.3''.

As time passes we cherry pick fixes from the development branch and backport those into the stable branch, the effect being that the stable branch should get more stable and less buggy over time. So the stable releases are ideal for people who don't need new features but would just like the software to work.

Our criteria for backporting changes are:

*

Documentation changes which don't affect any code are backported unless the documentation refers to a future feature which is not in stable.

*

Bug fixes which are not controversial, fix obvious problems, and have been well tested are backported.

*

Simple rearrangements of code which shouldn't affect how it works get backported. This is so that the code in the two branches doesn't get too far out of step, allowing us to backport future fixes more easily.

*

We don't backport new features, new APIs, new tools etc, except in one exceptional case: the new feature is required in order to implement an important bug fix.

A new stable branch starts when we think the new features in development are substantial and compelling enough over the current stable branch to warrant it. When that happens we create new stable and development versions 1.N.0 and 1.(N+1).0 [N is even]. The new dot-oh release won't necessarily be so stable at this point, but by backporting fixes from development, that branch will stabilize over time.

ENVIRONMENT VARIABLES

LIBGUESTFS_APPEND

Pass additional options to the guest kernel.

LIBGUESTFS_DEBUG

Set "LIBGUESTFS_DEBUG=1" to enable verbose messages. This has the same effect as calling "guestfs_set_verbose (g, 1)".

LIBGUESTFS_MEMSIZE

Set the memory allocated to the qemu process, in megabytes. For example:

  LIBGUESTFS_MEMSIZE=700
 
 

LIBGUESTFS_PATH

Set the path that libguestfs uses to search for kernel and initrd.img. See the discussion of paths in section PATH above.

LIBGUESTFS_QEMU

Set the default qemu binary that libguestfs uses. If not set, then the qemu which was found at compile time by the configure script is used.

See also ``QEMU WRAPPERS'' above.

LIBGUESTFS_TRACE

Set "LIBGUESTFS_TRACE=1" to enable command traces. This has the same effect as calling "guestfs_set_trace (g, 1)".

TMPDIR

Location of temporary directory, defaults to "/tmp".

If libguestfs was compiled to use the supermin appliance then the real appliance is cached in this directory, shared between all handles belonging to the same EUID. You can use $TMPDIR to configure another directory to use in case "/tmp" is not large enough.

SEE ALSO

guestfish(1), guestmount(1), virt-cat(1), virt-df(1), virt-edit(1), virt-inspector(1), virt-list-filesystems(1), virt-list-partitions(1), virt-ls(1), virt-make-fs(1), virt-rescue(1), virt-tar(1), virt-win-reg(1), qemu(1), febootstrap(1), hivex(3), <http://libguestfs.org/>.

Tools with a similar purpose: fdisk(8), parted(8), kpartx(8), lvm(8), disktype(1).

BUGS

To get a list of bugs against libguestfs use this link:

<https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools>

To report a new bug against libguestfs use this link:

<https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools>

When reporting a bug, please check:

*

That the bug hasn't been reported already.

*

That you are testing a recent version.

*

Describe the bug accurately, and give a way to reproduce it.

*

Run libguestfs-test-tool and paste the complete, unedited output into the bug report.

AUTHORS

Richard W.M. Jones ("rjones at redhat dot com")

COPYRIGHT

Copyright (C) 2009-2010 Red Hat Inc. <http://libguestfs.org/>

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA