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

       Kjetil Torgrim Homme

       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.

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.

       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)

       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.

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

       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.

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

-signal--signalsignal
              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, --delimiterdelimiter
              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, --pgrouppgrp,...
              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, --groupgid,...
              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, --oldersecs
              Select processes older than secs.

       -P, --parentppid,...
              Only match processes whose parent process ID is listed.

       -s, --sessionsid,...
              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, --terminalterm,...
              Only match processes whose controlling terminal is listed.  The terminal name should be  specified
              without the "/dev/" prefix.

       -u, --euideuid,...
              Only  match processes whose effective user ID is listed.  Either the numerical or symbolical value
              may be used.

       -U, --uiduid,...
              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, --pidfilefile
              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, --runstatesD,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.

       --cgroupname,...
              Match on provided control group (cgroup) v2 name. See cgroups(8)

       --nspid
              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.

       --nslistname,...
              Match only the provided namespaces. Available namespaces: ipc, mnt, net, pid, user, uts.

       -q, --queuevalue
              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.

       Please send bug reports to procps@freelists.org

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

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

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