Convert::UUlib.3pm

Langue: en

Version: 2009-10-28 (fedora - 01/12/10)

Section: 3 (Bibliothèques de fonctions)

NAME

Convert::UUlib - Perl interface to the uulib library (a.k.a. uudeview/uuenview).

SYNOPSIS

  use Convert::UUlib ':all';
  
  # read all the files named on the commandline and decode them
  # into the CURRENT directory. See below for a longer example.
  LoadFile $_ for @ARGV;
  for (my $i = 0; my $uu = GetFileListItem $i; $i++) {
     if ($uu->state & FILE_OK) {
       $uu->decode;
       print $uu->filename, "\n";
     }
  }
 
 

DESCRIPTION

Read the file doc/library.pdf from the distribution for in-depth information about the C-library used in this interface, and the rest of this document and especially the non-trivial decoder program at the end.

EXPORTED CONSTANTS

Action code constants

   ACT_IDLE      we don't do anything
   ACT_SCANNING  scanning an input file
   ACT_DECODING  decoding into a temp file
   ACT_COPYING   copying temp to target
   ACT_ENCODING  encoding a file
 
 

Message severity levels

   MSG_MESSAGE   just a message, nothing important
   MSG_NOTE      something that should be noticed
   MSG_WARNING   important msg, processing continues
   MSG_ERROR     processing has been terminated
   MSG_FATAL     decoder cannot process further requests
   MSG_PANIC     recovery impossible, app must terminate
 
 

Options

   OPT_VERSION   version number MAJOR.MINORplPATCH (ro)
   OPT_FAST      assumes only one part per file
   OPT_DUMBNESS  switch off the program's intelligence
   OPT_BRACKPOL  give numbers in [] higher precendence
   OPT_VERBOSE   generate informative messages
   OPT_DESPERATE try to decode incomplete files
   OPT_IGNREPLY  ignore RE:plies (off by default)
   OPT_OVERWRITE whether it's OK to overwrite ex. files
   OPT_SAVEPATH  prefix to save-files on disk
   OPT_IGNMODE   ignore the original file mode
   OPT_DEBUG     print messages with FILE/LINE info
   OPT_ERRNO     get last error code for RET_IOERR (ro)
   OPT_PROGRESS  retrieve progress information
   OPT_USETEXT   handle text messages
   OPT_PREAMB    handle Mime preambles/epilogues
   OPT_TINYB64   detect short B64 outside of Mime
   OPT_ENCEXT    extension for single-part encoded files
   OPT_REMOVE    remove input files after decoding (dangerous)
   OPT_MOREMIME  strict MIME adherence
   OPT_DOTDOT    ".."-unescaping has not yet been done on input files
   OPT_RBUF      set default read I/O buffer size in bytes
   OPT_WBUF      set default write I/O buffer size in bytes
   OPT_AUTOCHECK automatically check file list after every loadfile
 
 

Result/Error codes

   RET_OK        everything went fine
   RET_IOERR     I/O Error - examine errno
   RET_NOMEM     not enough memory
   RET_ILLVAL    illegal value for operation
   RET_NODATA    decoder didn't find any data
   RET_NOEND     encoded data wasn't ended properly
   RET_UNSUP     unsupported function (encoding)
   RET_EXISTS    file exists (decoding)
   RET_CONT      continue -- special from ScanPart
   RET_CANCEL    operation canceled
 
 

File States

  This code is zero, i.e. "false":
 
   UUFILE_READ   Read in, but not further processed
 
  The following state codes are or'ed together:
 
   FILE_MISPART  Missing Part(s) detected
   FILE_NOBEGIN  No 'begin' found
   FILE_NOEND    No 'end' found
   FILE_NODATA   File does not contain valid uudata
   FILE_OK       All Parts found, ready to decode
   FILE_ERROR    Error while decoding
   FILE_DECODED  Successfully decoded
   FILE_TMPFILE  Temporary decoded file exists
 
 

Encoding types

   UU_ENCODED    UUencoded data
   B64_ENCODED   Mime-Base64 data
   XX_ENCODED    XXencoded data
   BH_ENCODED    Binhex encoded
   PT_ENCODED    Plain-Text encoded (MIME)
   QP_ENCODED    Quoted-Printable (MIME)
   YENC_ENCODED  yEnc encoded (non-MIME)
 
 

EXPORTED FUNCTIONS

Initializing and cleanup

Initialize is automatically called when the module is loaded and allocates quite a small amount of memory for todays machines ;) CleanUp releases that again.

On my machine, a fairly complete decode with DBI backend needs about 10MB RSS to decode 20000 files.

Initialize
Not normally necessary, (re-)initializes the library.
CleanUp
Not normally necessary, could be called at the end to release memory before starting a new decoding round.

Setting and querying options

$option = GetOption OPT_xxx
SetOption OPT_xxx, opt-value

See the "OPT_xxx" constants above to see which options exist.

Setting various callbacks

SetMsgCallback [callback-function]
SetBusyCallback [callback-function]
SetFileCallback [callback-function]
SetFNameFilter [callback-function]

Call the currently selected FNameFilter

$file = FNameFilter $file

Loading sourcefiles, optionally fuzzy merge and start decoding

($retval, $count) = LoadFile $fname, [$id, [$delflag, [$partno]]]
Load the given file and scan it for encoded contents. Optionally tag it with the given id, and if $delflag is true, delete the file after it is no longer necessary. If you are certain of the part number, you can specify it as the last argument.

A better (usually faster) way of doing this is using the "SetFNameFilter" functionality.

$retval = Smerge $pass
If you are desperate, try to call "Smerge" with increasing $pass values, beginning at 0, to try to merge parts that usually would not have been merged.

Most probably this will result in garbled files, so never do this by default, except:

If the "OPT_AUTOCHECK" option has been disabled (by default it is enabled) to speed up file loading, then you have to call "Smerge -1" after loading all files as an additional pre-pass (which is normally done by "LoadFile").

$item = GetFileListItem $item_number
Return the $item structure for the $item_number'th found file, or "undef" of no file with that number exists.

The first file has number 0, and the series has no holes, so you can iterate over all files by starting with zero and incrementing until you hit "undef".

Decoding files

$retval = $item->rename($newname)
Change the ondisk filename where the decoded file will be saved.
$retval = $item->decode_temp
Decode the file into a temporary location, use "$item->infile" to retrieve the temporary filename.
$retval = $item->remove_temp
Remove the temporarily decoded file again.
$retval = $item->decode([$target_path])
Decode the file to it's destination, or the given target path.
$retval = $item->info(callback-function)

Querying (and setting) item attributes

$state = $item->state
$mode = $item->mode([newmode])
$uudet = $item->uudet
$size = $item->size
$filename = $item->filename([newfilename})
$subfname = $item->subfname
$mimeid = $item->mimeid
$mimetype = $item->mimetype
$binfile = $item->binfile

Information about source parts

$parts = $item->parts
Return information about all parts (source files) used to decode the file as a list of hashrefs with the following structure:
  {
    partno   => <integer describing the part number, starting with 1>,
    # the following member sonly exist when they contain useful information
    sfname   => <local pathname of the file where this part is from>,
    filename => <the ondisk filename of the decoded file>,
    subfname => <used to cluster postings, possibly the posting filename>,
    subject  => <the subject of the posting/mail>,
    origin   => <the possible source (From) address>,
    mimetype => <the possible mimetype of the decoded file>,
    mimeid   => <the id part of the Content-Type>,
  }
 
 

Usually you are interested mostly the "sfname" and possibly the "partno" and "filename" members.

Functions below not documented and not very well tested

   QuickDecode
   EncodeMulti
   EncodePartial
   EncodeToStream
   EncodeToFile
   E_PrepSingle
   E_PrepPartial
 
 

EXTENSION FUNCTIONS

Functions found in this module but not documented in the uulib documentation:
$msg = straction ACT_xxx
Return a human readable string representing the given action code.
$msg = strerror RET_xxx
Return a human readable string representing the given error code.
$str = strencoding xxx_ENCODED
Return the name of the encoding type as a string.
$str = strmsglevel MSG_xxx
Returns the message level as a string.
SetFileNameCallback $cb
Sets (or queries) the FileNameCallback, which is called whenever the decoding library can't find a filename and wants to extract a filename from the subject line of a posting. The callback will be called with two arguments, the subject line and the current candidate for the filename. The latter argument can be "undef", which means that no filename could be found (and likely no one exists, so it is safe to also return "undef" in this case). If it doesn't return anything (not even "undef"!), then nothing happens, so this is a no-op callback:
    sub cb {
       return ();
    }
 
 

If it returns "undef", then this indicates that no filename could be found. In all other cases, the return value is taken to be the filename.

This is a slightly more useful callback:

   sub cb {
      return unless $_[1]; # skip "Re:"-plies et al.
      my ($subject, $filename) = @_;
      # if we find some *.rar, take it
      return $1 if $subject =~ /(\w+\.rar)/;
      # otherwise just pass what we have
      return ();
   }
 
 

LARGE EXAMPLE DECODER

This is the file "example-decoder" from the distribution, put here instead of more thorough documentation.
    #!/usr/bin/perl
 
    # decode all the files in the directory uusrc/ and copy
    # the resulting files to uudst/
 
    use Convert::UUlib ':all';
 
    sub namefilter {
       my ($path) = @_;
 
       $path=~s/^.*[\/\\]//;
 
       $path
    }
 
    sub busycb {
       my ($action, $curfile, $partno, $numparts, $percent, $fsize) = @_;
       $_[0]=straction($action);
       print "busy_callback(", (join ",",@_), ")\n";
       0
    }
 
    SetOption OPT_RBUF, 128*1024;
    SetOption OPT_WBUF, 1024*1024;
    SetOption OPT_IGNMODE, 1;
    SetOption OPT_IGNMODE, 1;
    SetOption OPT_VERBOSE, 1;
 
    # show the three ways you can set callback functions. I normally
    # prefer the one with the sub inplace.
    SetFNameFilter \&namefilter;
 
    SetBusyCallback "busycb", 333;
 
    SetMsgCallback sub {
       my ($msg, $level) = @_;
       print uc strmsglevel $_[1], ": $msg\n";
    };
 
    # the following non-trivial FileNameCallback takes care
    # of some subject lines not detected properly by uulib:
    SetFileNameCallback sub {
       return unless $_[1]; # skip "Re:"-plies et al.
       local $_ = $_[0];
 
       # the following rules are rather effective on some newsgroups,
       # like alt.binaries.games.anime, where non-mime, uuencoded data
       # is very common
 
       # if we find some *.rar, take it as the filename
       return $1 if /(\S{3,}\.(?:[rstuvwxyz]\d\d|rar))\s/i;
 
       # one common subject format
       return $1 if /- "(.{2,}?\..+?)" (?:yenc )?\(\d+\/\d+\)/i;
 
       # - filename.par (04/55)
       return $1 if /- "?(\S{3,}\.\S+?)"? (?:yenc )?\(\d+\/\d+\)/i;
 
       # - (xxx) No. 1 sayuri81.jpg 756565 bytes
       # - (20 files) No.17 Roseanne.jpg [2/2]
       return $1 if /No\.[ 0-9]+ (\S+\....) (?:\d+ bytes )?\[/;
 
       # try to detect some common forms of filenames
       return $1 if /([a-z0-9_\-+.]{3,}\.[a-z]{3,4}(?:.\d+))/i;
 
       # otherwise just pass what we have
       ()
    };
 
    # now read all files in the directory uusrc/*
    for(<uusrc/*>) {
       my ($retval, $count) = LoadFile ($_, $_, 1);
       print "file($_), status(", strerror $retval, ") parts($count)\n";
    }
 
    SetOption OPT_SAVEPATH, "uudst/";
 
    # now wade through all files and their source parts
    $i = 0;
    while ($uu = GetFileListItem $i) {
       $i++;
       print "file nr. $i";
       print " state ", $uu->state;
       print " mode ", $uu->mode;
       print " uudet ", strencoding $uu->uudet;
       print " size ", $uu->size;
       print " filename ", $uu->filename;
       print " subfname ", $uu->subfname;
       print " mimeid ", $uu->mimeid;
       print " mimetype ", $uu->mimetype;
       print "\n";
 
       # print additional info about all parts
       for ($uu->parts) {
          while (my ($k, $v) = each %$_) {
             print "$k > $v, ";
          }
          print "\n";
       }
 
       print $uu->filename;
 
       $uu->remove_temp;
 
       if (my $err = $uu->decode ()) {
          print ", ", strerror $err, "\n";
       } else {
          print ", saved as uudst/", $uu->filename, "\n";
       }
    }
 
    print "cleanup...\n";
 
    CleanUp;
 
 

AUTHOR

Marc Lehmann <schmorp@schmorp.de>, the original uulib library was written by Frank Pilhofer <fp@informatik.uni-frankfurt.de>, and later heavily bugfixed by Marc Lehmann.

SEE ALSO

perl(1), uudeview homepage at http://www.uni-frankfurt.de/~fp/uudeview/.