start_daemon

Langue: en

Version: Nov 10, 2000 (openSuse - 09/10/07)

Section: 8 (Commandes administrateur)

NAME

Startproc - Start processes identified by path name
Start_daemon - Start processes identified by path name

SYNOPSIS

startproc [-f] [-L] [[-n ]+/-<prio>] [-s] [-t sec] [-u user] [-g group] [-v] [-e] [-l log_file |-q|-d] [-p pid_file] [-i ignore_file] [-c root] /path/to/executable [arguments for executable]

start_daemon [-f] [-n +/-<prio>] /path/to/executable [arguments for executable]

DESCRIPTION

startproc and the LSB variant start_daemon check for all processes of the specified executable and starts it if no processes are found. Note that startproc is designed to start a daemon but not a kernel thread or a program which enables a kernel thread.

startproc does not use the pid to search for a process but the full path of the corresponding program which is used to identify the executable (see proc(5)). Only if the inode number (/proc/<pid>/exe) and the full name are unavailable (/proc/<pid>/cmdline) or if the executable changes its zeroth argument, startproc uses the base name (/proc/<pid>/stat) to identify the running program.

Extended functionality is provided by the -p option (former option -f changed due to the LSB specification). If this option is specified, startproc tries to check against the pid read from this file instead of the default (/var/run/<basename>.pid). The pid read from this file is compared against the pids of possible running processes that use the specified executable. In order to avoid confusion with stale pid files, a not up-to-date pid will be ignored.

For the possibility of having two different sessions of one binary program, the option -i ignore_file allows to specify a pid file which pid number is used to ignore all processes of corresponding process session.

The option -v makes startproc print out verbose diagnostics.

REQUIRED

/path/to/executable
Specifies the executable by its full path name. This argument is always required. Everything that follows this path is considered options for the executable to be launched. Further information can be obtained from the respective manpage(s).

OPTIONS

[-n ]+/-<prio>
Set the nice level for the process. If used, this option should always be the first in the command line. The nice level <prio> may be specified in the range between -20 and +20. Only root is allowed to set negative nice values.
-e
Bequeath only a minimal set of environment variables to the new process: HOME, PATH, SHELL, RUNLEVEL, and PREVLEVEL.
-p pid_file
(Former option -f changed due to the LSB specification.) Use an alternate pid file instead of the default (/var/run/<basename>.pid). The pid read from this file is being matched against the pid of running processes that have an executable with specified path. of the program. In order to avoid confusion with stale pid files, a not up-to-date pid will be ignored.
-i ignore_file
The pid found in this file is used as session id of the same binary program which should be ignored by startproc.
-f
This option is required by the Linux Standard Base Specification (LSB). With this option the start of a process is forced.
-g group
Sets the group ID of the process to gid.
-l log_file
Redirect the process standard output and standard error to the file log_file.
-L
This option causes symlinks to be followed, as the like-named option in ls(1). BR Note : for the file name the original name of the program is used instead of the name of the symbolic link.
-c root
Change root directory to root. Services which have been started with this option can only be checked by checkproc(8) and signaled by killproc(8) if checkproc(8) and killproc(8) are called with the same option argument for the option -c.
-q
Equals to -l /dev/null (supresses output).
-d
Let startproc expect that the started service will do a dialog by prompting for, e.g. a passphrase. This option implies a timeout of 15 seconds (-t 15).
-s
Starts the process in a new session. The new task is a process group leader and has no controlling tty.
-t sec
The number of seconds to wait after the successful start of a service. This options accepts the number of seconds to wait. You can specify some units after a given number: s for seconds, m for minutes, and h for hours to wait.
-u user
Sets the user ID of the process to user.
-v
Verbose output.

EXAMPLE

startproc /usr/sbin/sendmail
starts /usr/sbin/sendmail if no sendmail process is found. If a pid file sendmail.pid exists in /var/run/, then the pid found in this file is used to search the process table for a process with an executable that matches the specified pathname, /usr/sbin/sendmail. If no matching process is found, /usr/sbin/sendmail is launched.
startproc -p /var/myrun/lpd.pid /usr/sbin/lpd
starts /usr/sbin/lpd if there is no process with the pid found in /var/myrun/lpd.pid and no process in the actual process table exists that uses the specified binary.

EXIT CODES

The exit codes have the following LSB conform conditions:
0
Success
1
Generic or unspecified error
2
Invalid or excess argument(s)
4
Insufficient privilege(s)
5
Program is not installed
7
Program is not running

In some error cases, diagnostic output is sent to standard error, or, if standard error is not available, syslogd(8) is being used.

NOTE

startproc is a replacement for the Bourne shell function daemon found in the widely used SysVinit package of Miquel van Smoorenburg, <miquels@cistron.nl>. startproc is not useful to start kernel threads. This should be done by service utilities designed for the purpose to accomplish this task.

BUGS

Identifying a process based on the executable file and the corresponding inode number only works if the process stays alive during startproc's execution. Processes rewriting their zeroth argument or shell scripts (the inode number of the shell executable file is not identical to that of the script file) may not be identified by a filename path.

Startproc does not start a process if there already exists one being in the zombie state. Zombies are processes which arn't alive but listed in the process table to have the exit status ready for the corresponding parent processes. Therefore the parent processes should be check out.

FILES

/proc/
path to the proc file system (see proc(5)).
/etc/init.d/
path to the SuSE boot concept script base directory as required by the Linux Standard Base Specification (LSB) (see init.d(7)).

SEE ALSO

checkproc(8), killproc(8), insserv(8), init.d(7), kill(1), skill(1), killall(8), killall5(8), signal(7), proc(5). 1994-2000 Werner Fink, 1996-2000 SuSE GmbH Nuernberg, Germany.

AUTHOR

Werner Fink <werner@suse.de>