pgrep(1) — Linux manual page
PGREP(1) User Commands PGREP(1)
NAME
pgrep, pkill, pidwait - look up, signal, or wait for processes
based on name and other attributes
SYNOPSIS
pgrep [option ...] pattern
pkill [option ...] pattern
pidwait [option ...] pattern
DESCRIPTION
pgrep looks through the currently running processes and lists the
process IDs which match the selection criteria to stdout. All
the criteria have to match. For example,
$ pgrep -u root sshd
will only list the processes whose name include sshd AND owned by
root. On the other hand,
$ pgrep -u root,daemon
will list the processes owned by root OR daemon.
pkill will send the specified signal (by default SIGTERM) to each
process instead of listing them on stdout.
pidwait will wait for each process instead of listing them on
stdout.
OPTIONS
-signal
--signal signal
Defines the signal to send to each matched process.
Either the numeric or the symbolic signal name can be
used. In pgrep or pidwait mode only the long option can be
used and has no effect unless used in conjunction with
--require-handler to filter to processes with a userspace
signal handler present for a particular signal.
-c, --count
Suppress normal output; instead print a count of matching
processes. When count does not match anything, e.g.
returns zero, the command will return non-zero value. Note
that for pkill and pidwait, the count is the number of
matching processes, not the processes that were
successfully signaled or waited for.
-d, --delimiter delimiter
Sets the string used to delimit each process ID in the
output (by default a newline). (pgrep only.)
-e, --echo
Display name and PID of the process being killed. (pkill
only.)
-f, --full
The pattern is normally only matched against the process
name. When -f is set, the full command line is used.
-g, --pgroup pgrp,...
Only match processes in the process group IDs listed.
Process group 0 is translated into pgrep's, pkill's, or
pidwait's own process group.
-G, --group gid,...
Only match processes whose real group ID is listed.
Either the numerical or symbolical value may be used.
-i, --ignore-case
Match processes case-insensitively.
-l, --list-name
List the process name as well as the process ID. (pgrep
only.)
-a, --list-full
List the full command line as well as the process ID.
(pgrep only.)
-n, --newest
Select only the newest (most recently started) of the
matching processes.
-o, --oldest
Select only the oldest (least recently started) of the
matching processes.
-O, --older secs
Select processes older than secs.
-P, --parent ppid,...
Only match processes whose parent process ID is listed.
-s, --session sid,...
Only match processes whose process session ID is listed.
Session ID 0 is translated into pgrep's, pkill's, or
pidwait's own session ID.
-t, --terminal term,...
Only match processes whose controlling terminal is listed.
The terminal name should be specified without the "/dev/"
prefix.
-u, --euid euid,...
Only match processes whose effective user ID is listed.
Either the numerical or symbolical value may be used.
-U, --uid uid,...
Only match processes whose real user ID is listed. Either
the numerical or symbolical value may be used.
-v, --inverse
Negates the matching. This option is usually used in
pgrep's or pidwait's context. In pkill's context the
short option is disabled to avoid accidental usage of the
option.
-w, --lightweight
Shows all thread ids instead of pids in pgrep's or
pidwait's context. In pkill's context this option is
disabled.
-x, --exact
Only match processes whose names (or command lines if -f
is specified) exactly match the pattern.
-F, --pidfile file
Read PIDs from file. This option is more useful for pkill
or pidwait than pgrep. The filename "-" can be used to
read from STDIN.
-L, --logpidfile
Fail if pidfile (see -F) not locked.
-r, --runstates D,R,S,Z,...
Match only processes which match the process state.
-A, --ignore-ancestors
Ignore all ancestors of pgrep, pkill, or pidwait. For
example, this can be useful when elevating with sudo or
similar tools.
-H, --require-handler
Only match processes with a userspace signal handler
present for the signal to be sent.
--cgroup name,...
Match on provided control group (cgroup) v2 name. See
cgroups(8)
--env name[=value],...
Match on process that have these environent variables. If
the =value parameter is not defined then only the variable
name is matched.
--ns pid
Match processes that belong to the same namespaces.
Required to run as root to match processes from other
users. See --nslist for how to limit which namespaces to
match.
--nslist name,...
Match only the provided namespaces. Available namespaces:
ipc, mnt, net, pid, user, uts.
-q, --queue value
Use sigqueue(3) rather than kill(2) and the value argument
is used to specify an integer to be sent with the signal.
If the receiving process has installed a handler for this
signal using the SA_SIGINFO flag to sigaction(2), then it
can obtain this data via the si_value field of the
siginfo_t structure.
-V, --version
Display version information and exit.
-h, --help
Display help and exit.
OPERANDS
pattern
Specifies an Extended Regular Expression for matching
against the process names or command lines.
EXAMPLES
Example 1: Find the process ID of the named daemon:
$ pgrep -u root named
Example 2: Make syslog reread its configuration file:
$ pkill -HUP syslogd
Example 3: Give detailed information on all xterm processes:
$ ps -fp $(pgrep -d, -x xterm)
Example 4: Make all chrome processes run nicer:
$ renice +4 $(pgrep chrome)
Example 5: Wait for a process with a known PID to finish:
$ echo ${PID} | pidwait -F -
EXIT STATUS
0 One or more processes matched the criteria. For pkill and
pidwait, one or more processes must also have been
successfully signalled or waited for.
1 No processes matched or none of them could be signalled.
2 Syntax error in the command line.
3 Fatal error: out of memory etc.
NOTES
The process name used for matching is limited to the 15
characters present in the output of /proc/pid/stat. Use the -f
option to match against the complete command line,
/proc/pid/cmdline. Threads may not have the same process name as
the parent process but will have the same command line.
The running pgrep, pkill, or pidwait process will never report
itself as a match.
The -O --older option will silently fail if /proc is mounted with
the subset=pid option.
BUGS
The options -n and -o and -v can not be combined. Let me know if
you need to do this.
Defunct processes are reported.
pidwait requires the pidfd_open(2) system call which first
appeared in Linux 5.3.
SEE ALSO
ps(1), regex(7), signal(7), sigqueue(3), killall(1), skill(1),
kill(1), kill(2), cgroups(8).
AUTHOR
Kjetil Torgrim Homme ⟨kjetilho@ifi.uio.no⟩
REPORTING BUGS
Please send bug reports to ⟨procps@freelists.org⟩.
COLOPHON
This page is part of the procps-ng (/proc filesystem utilities)
project. Information about the project can be found at
⟨https://gitlab.com/procps-ng/procps⟩. If you have a bug report
for this manual page, see
⟨https://gitlab.com/procps-ng/procps/blob/master/Documentation/bugs.md⟩.
This page was obtained from the project's upstream Git repository
⟨https://gitlab.com/procps-ng/procps.git⟩ on 2024-06-14. (At
that time, the date of the most recent commit that was found in
the repository was 2024-06-04.) If you discover any rendering
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procps-ng 2024-02-05 PGREP(1)
Pages that refer to this page: fuser(1), kill(1@@procps-ng), killall(1), pidof(1), pmap(1), ps(1), pslog(1), pwdx(1), skill(1)