pkill(1) look up or signal processes based on name and other attributes

Other Alias

pgrep

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 netscape processes run nicer:

$ renice +4 $(pgrep netscape)

EXIT STATUS

0
One or more processes matched the criteria.
1
No processes matched.
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.

AUTHOR

Kjetil Torgrim Homme

REPORTING BUGS

Please send bug reports to