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 cgroups(8)

       --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 re‐
              ceiving 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)

EXIT STATUS
       0      One  or  more  processes matched the criteria. For pkill and pid‐
              wait, one or more processes must also have been successfully sig‐
              nalled 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

REPORTING BUGS
       Please send bug reports to procps@freelists.org

procps‐ng                          2023‐01‐16                          PGREP(1)