man > pidwait(1)

PGREP(1)                                    User Commands                                   PGREP(1)

NAME
       pgrep,  pkill,  pidwait  - look up, signal, or wait for processes based on name and other at‐
       tributes

SYNOPSIS
       pgrep [options] pattern
       pkill [options] pattern
       pidwait [options] 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 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 stdout.

OPTIONS
       -signal
       --signal signal
              Defines  the  signal  to send to each matched process.  Either the numeric or the sym‐
              bolic 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  symboli‐
              cal 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 sym‐
              bolical 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 op‐
              tion.

       -w, --lightweight
              Shows all thread ids instead of pids in pgrep's or pidwait's context.  In pkill's con‐
              text 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.

       -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 inte‐
              ger  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)

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/cmd‐
       line. 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
       ]8;;kjetilho AT ifi.no\Kjetil Torgrim Homme]8;;\

REPORTING BUGS
       Please send bug reports to ]8;;procps AT freelists.org\procps AT freelists.org]8;;\

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