# phpman > man > pkill(1) > **TLDR:** Signal process by name. > - Kill all processes which match: `pkill "{{process_name}}"` - Kill all processes which match their full command instead of just the process name: `pkill {{-f|--full}} "{{command_name}}"` - Force kill matching processes (can't be blocked): `pkill -9 "{{process_name}}"` - Send SIGUSR1 signal to processes which match: `pkill -USR1 "{{process_name}}"` - Kill the main `firefox` process to close the browser: `pkill {{-o|--oldest}} "{{firefox}}"` *Source: tldr-pages* --- [PGREP(1)](https://www.chedong.com/phpMan.php/man/PGREP/1/markdown) User Commands [PGREP(1)](https://www.chedong.com/phpMan.php/man/PGREP/1/markdown) ## 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. (**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. 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 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 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 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 Select processes older than secs. ### -P --parent Only match processes whose parent process ID is listed. ### -s --session 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 Only match processes whose controlling terminal is listed. The terminal name should be specified without the "/dev/" prefix. ### -u --euid Only match processes whose effective user ID is listed. Either the numerical or sym‐ bolical value may be used. ### -U --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 Read _PID_s from _file_. This option is more useful for **pkill**or**pidwait** than **pgrep**. ### -L --logpidfile Fail if pidfile (see **-F**) not locked. ### -r --runstates Match only processes which match the process state. **--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 Use [**sigqueue(3)](https://www.chedong.com/phpMan.php/man/sigqueue/3/markdown)** rather than [**kill(2)](https://www.chedong.com/phpMan.php/man/kill/2/markdown)** 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)](https://www.chedong.com/phpMan.php/man/sigaction/2/markdown)** , 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 pro‐ cesses 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. The running **pgrep**, **pkill**, or **pidwait** 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)](https://www.chedong.com/phpMan.php/man/ps/1/markdown), [**regex**(7)](https://www.chedong.com/phpMan.php/man/regex/7/markdown), [**signal**(7)](https://www.chedong.com/phpMan.php/man/signal/7/markdown), [**sigqueue**(3)](https://www.chedong.com/phpMan.php/man/sigqueue/3/markdown), [**killall**(1)](https://www.chedong.com/phpMan.php/man/killall/1/markdown), [**skill**(1)](https://www.chedong.com/phpMan.php/man/skill/1/markdown), [**kill**(1)](https://www.chedong.com/phpMan.php/man/kill/1/markdown), [**kill**(2)](https://www.chedong.com/phpMan.php/man/kill/2/markdown) ## AUTHOR Kjetil Torgrim Homme ⟨⟩ ## REPORTING BUGS Please send bug reports to ⟨⟩ procps-ng 2020-06-04 [PGREP(1)](https://www.chedong.com/phpMan.php/man/PGREP/1/markdown)