PKILL(1) General Commands Manual PKILL(1)

pgrep, pkillfind or signal processes by name

pgrep [-Lafilnoqvx] [-F pidfile] [-G gid] [-P ppid] [-U uid] [-d delim] [-g pgrp] [-t tty] [-u euid] pattern ...

pkill [-signal] [-ILafilnovx] [-F pidfile] [-G gid] [-P ppid] [-U uid] [-g pgrp] [-t tty] [-u euid] pattern ...

The pgrep command searches the process table on the running system and prints the process IDs of all processes that match the criteria given on the command line.

The pkill command searches the process table on the running system and signals all processes that match the criteria given on the command line.

The following options are available:

pidfile
Restrict matches to a process whose PID is stored in the pidfile file.
gid
Restrict matches to processes with a real group ID in the comma-separated list gid.
Request confirmation before attempting to signal each process.
The pidfile file given for the -F option must be locked with the flock(2) syscall or created with pidfile(3).
ppid
Restrict matches to processes with a parent process ID in the comma-separated list ppid.
uid
Restrict matches to processes with a real user ID in the comma-separated list uid.
delim
Specify a delimiter to be printed between each process ID. The default is a newline. This option can only be used with the pgrep command.
Include process ancestors in the match list. By default, the current pgrep or pkill process and all of its ancestors are excluded (unless -v is used).
Match against full argument lists. The default is to match against process names.
pgrp
Restrict matches to processes with a process group ID in the comma-separated list pgrp. The value zero is taken to mean the process group ID of the running pgrep or pkill command.
Ignore case distinctions in both the process table and the supplied pattern.
Long output. For pgrep, print the process name in addition to the process ID for each matching process. If used in conjunction with -f, print the process ID and the full argument list for each matching process. For pkill, display the kill command used for each process killed.
Select only the newest (most recently started) of the matching processes.
Select only the oldest (least recently started) of the matching processes.
For pgrep, Do not write anything to standard output.
tty
Restrict matches to processes associated with a terminal in the comma-separated list tty. Terminal names may be of the form ttyxx or the shortened form xx. A single dash (‘-’) matches processes not associated with a terminal.
euid
Restrict matches to processes with an effective user ID in the comma-separated list euid.
Reverse the sense of the matching; display processes that do not match the given criteria.
Require an exact match of the process name, or argument list if -f is given. The default is to match any substring.
-signal
A non-negative decimal number or symbolic signal name specifying the signal to be sent instead of the default TERM. This option is valid only when given as the first argument to pkill.

If any pattern operands are specified, they are used as extended regular expressions to match the command name or full argument list of each process.

Note that a running pgrep or pkill process will never consider itself as a potential match.

The pgrep and pkill utilities return one of the following values upon exit:

0
One or more processes were matched.
1
No processes were matched.
2
Invalid options were specified on the command line.
3
An internal error occurred.

Show the pid of the process holding the /tmp/.X0-lock pid file:

$ pgrep -F /tmp/.X0-lock
1211

Show long output for firefox processes:

$ pgrep -l firefox
1312 firefox
1309 firefox
1288 firefox
1280 firefox
1279 firefox
1278 firefox
1277 firefox
1264 firefox

Same as above but just showing the pid of the most recent process:

$ pgrep -n firefox
1312

Look for vim processes. Match against the full argument list:

$ pgrep -f vim
44968
30790

Same as above but matching against the ‘list’ word and showing the full argument list:

$ pgrep -f -l list
30790 vim list.txt

Send SIGSTOP signal to processes that are an exact match:

$ pkill -SIGSTOP -f -x "vim list.txt"

Without -f names over 19 characters will silently fail:

$ vim this_is_a_very_long_file_name &
[1] 36689
$

[1]+  Stopped                 vim this_is_a_very_long_file_name
$ pgrep "vim this"
$

Same as above using the -f flag:

$ pgrep -f "vim this"
36689

kill(1), killall(1), ps(1), flock(2), kill(2), sigaction(2), pidfile(3), re_format(7)

The pkill and pgrep utilities first appeared in NetBSD 1.6. They are modelled after utilities of the same name that appeared in Sun Solaris 7. They made their first appearance in FreeBSD 5.3.

Andrew Doran <ad@NetBSD.org>

October 5, 2020 macOS 15.2