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NAME

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

SYNOPSIS

pgrep [options] pattern
pkill
[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.

OPTIONS

-signal
--signal
signal

Defines the signal to send to each matched process. Either the numeric or the symbolic signal name can be used. (pkill only.)

-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.

-d, --delimiter delimiter

Sets the string used to delimit each process ID in the output (by default a newline). (pgrep 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 or pkill’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.

-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 or pkill’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 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 context. In pkill’s context this option is disabled.

-x, --exact

Only match processes whose names (or command line if -f is specified) exactly match the pattern.

-F, --pidfile file

Read PID’s from file. This option is perhaps more useful for pkill than pgrep.

-L, --logpidfile

Fail if pidfile (see -F) not locked.

--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.

-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 the process must also have been successfully signalled.

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.

The running pgrep or pkill process will never report itself as a match.

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.

SEE ALSO

ps(1), regex(7), signal(7), killall(1), skill(1), kill(1), kill(2)

AUTHOR

kjetilho [AT] ifi.no">Kjetil Torgrim Homme

REPORTING BUGS

Please send bug reports to procps [AT] freelists.org">procps [AT] freelists.org

COMMENTS