Section: User Commands (1)
Updated: October 2012
pgrep [options] pattern
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.
- --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.:
- -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 PIDs 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.:
- Specifies an Extended Regular Expression for matching against the process names or command lines.:
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)
- One or more processes matched the criteria.:
- No processes matched.:
- Syntax error in the command line.:
- Fatal error: out of memory etc.:
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 options -n and -o and -v can not be combined. Let me know if you need to do this.
Defunct processes are reported.
Please send bug reports to