PIDOF(8) Linux System Administrator's Manual PIDOF(8)
NAME
pidof - find the process ID of a running program
SYNOPSIS
pidof [-s] [-c] [-n] [-x] [-z] [-o omitpid[,omitpid...]] [-o omit-
pid[,omitpid...]...] [-d sep] program [program...]
DESCRIPTION
pidof finds the process id's (PIDs) of the named programs. It prints
those id's on the standard output. This program is on some systems used
in run-level change scripts, especially when the system has a System-V
like rc structure. In that case these scripts are located in
/etc/rc?.d, where ? is the runlevel. If the system has a start-stop-
daemon(8) program that should be used instead.
OPTIONS
-s Single shot - this instructs the program to only return one pid.
-c Only return process PIDs that are running with the same root di-
rectory. This option is ignored for non-root users, as they will
be unable to check the current root directory of processes they
do not own.
-n Avoid stat(2) system function call on all binaries which are lo-
cated on network based file systems like NFS. Instead of using
this option the variable PIDOF_NETFS may be set and exported.
-q Do not display matched PIDs to standard out. Simply exit with a
status of true or false to indicate whether a matching PID was
found.
-x Scripts too - this causes the program to also return process id's
of shells running the named scripts.
-z Try to detect processes which are stuck in zombie (Z) status.
Usually these processes are skipped as trying to deal with them
can cause pidof or related tools to hang. Note: In the past
pidof would ignore processes in the uninterruptable state (D),
unless the -z flag was specified. This is no longer the case.
The pidof program will find and report processes in the D state
whether -z is specified or not.
-d sep Tells pidof to use sep as an output separator if more than one
PID is shown. The default separator is a space.
-o omitpid
Tells pidof to omit processes with that process id. The special
pid %PPID can be used to name the parent process of the pidof
program, in other words the calling shell or shell script.
EXIT STATUS
0 At least one program was found with the requested name.
1 No program was found with the requested name.
NOTES
pidof is actually the same program as killall5(8); the program behaves
according to the name under which it is called.
When pidof is invoked with a full pathname to the program it should find
the pid of, it is reasonably safe. Otherwise it is possible that it re-
turns PIDs of running programs that happen to have the same name as the
program you're after but are actually other programs. Note that the ex-
ecutable name of running processes is calculated with readlink(2), so
symbolic links to executables will also match.
Zombie processes or processes in disk sleep (states Z and D, respec-
tively) are ignored, as attempts to access the stats of these will some-
times fail. The -z flag (see above) tells pidof to try to detect these
sleeping and zombie processes, at the risk of failing or hanging.
SEE ALSO
shutdown(8), init(8), halt(8), reboot(8), killall5(8)
AUTHOR
]8;;mailto:miquels@cistron.nl\Miquel van Smoorenburg]8;;\
sysvinit 01 Sep 1998 PIDOF(8)
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