pgrep(1) — Linux manual page


PGREP(1)                      User Commands                     PGREP(1)

NAME         top

       pgrep, pkill, pidwait - look up, signal, or wait for processes
       based on name and other attributes

SYNOPSIS         top

       pgrep [options] pattern
       pkill [options] pattern
       pidwait [options] pattern

DESCRIPTION         top

       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 called 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

OPTIONS         top

       --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

       -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

       -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/"

       -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

       -w, --lightweight
              Shows all thread ids instead of pids in pgrep's or
              pidwait's context.  In pkill's context this option is

       -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.

       -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

       --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

       --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         top

              Specifies an Extended Regular Expression for matching
              against the process names or command lines.

EXAMPLES         top

       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)

EXIT STATUS         top

       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         top

       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         top

       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         top

       ps(1), regex(7), signal(7), sigqueue(3), killall(1), skill(1),
       kill(1), kill(2), cgroups(8).

AUTHOR         top

       Kjetil Torgrim Homme ⟨⟩

REPORTING BUGS         top

       Please send bug reports to ⟨⟩

COLOPHON         top

       This page is part of the procps-ng (/proc filesystem utilities)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report
       for this manual page, see
       This page was obtained from the project's upstream Git repository
       ⟨⟩ on 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-10-16.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
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       (which is not part of the original manual page), send a mail to

procps-ng                      2023-10-04                       PGREP(1)

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