1PGREP(1) User Commands PGREP(1)
2
6 pgrep, pkill, pidwait - look up, signal, or wait for processes based on
7 name and other attributes
8
10 pgrep [options] pattern
11 pkill [options] pattern
12 pidwait [options] pattern
13
15 pgrep looks through the currently running processes and lists the
16 process IDs which match the selection criteria to stdout. All the cri‐
17 teria have to match. For example,
18 $ pgrep -u root sshd
20 will only list the processes called sshd AND owned by root. On the
22 other hand,
23 $ pgrep -u root,daemon
25 will list the processes owned by root OR daemon.
27 pkill will send the specified signal (by default SIGTERM) to each
29 process instead of listing them on stdout.
30 pidwait will wait for each process instead of listing them on stdout.
32
34 -signal
35 --signal signal
36 Defines the signal to send to each matched process. Either the
37 numeric or the symbolic signal name can be used. In pgrep or
38 pidwait mode this has no effect unless used in conjunction with
39 --require-handler to filter to processes with a userspace signal
40 handler present for a particular signal.
41 -c, --count
44 Suppress normal output; instead print a count of matching pro‐
45 cesses. When count does not match anything, e.g. returns zero,
46 the command will return non-zero value. Note that for pkill and
47 pidwait, the count is the number of matching processes, not the
48 processes that were successfully signaled or waited for.
49 -d, --delimiter delimiter
51 Sets the string used to delimit each process ID in the output
52 (by default a newline). (pgrep only.)
53 -e, --echo
55 Display name and PID of the process being killed. (pkill only.)
56 -f, --full
58 The pattern is normally only matched against the process name.
59 When -f is set, the full command line is used.
60 -g, --pgroup pgrp,...
62 Only match processes in the process group IDs listed. Process
63 group 0 is translated into pgrep's, pkill's, or pidwait's own
64 process group.
65 -G, --group gid,...
67 Only match processes whose real group ID is listed. Either the
68 numerical or symbolical value may be used.
69 -i, --ignore-case
71 Match processes case-insensitively.
72 -l, --list-name
74 List the process name as well as the process ID. (pgrep only.)
75 -a, --list-full
77 List the full command line as well as the process ID. (pgrep
78 only.)
79 -n, --newest
81 Select only the newest (most recently started) of the matching
82 processes.
83 -o, --oldest
85 Select only the oldest (least recently started) of the matching
86 processes.
87 -O, --older secs
89 Select processes older than secs.
90 -P, --parent ppid,...
92 Only match processes whose parent process ID is listed.
93 -s, --session sid,...
95 Only match processes whose process session ID is listed. Ses‐
96 sion ID 0 is translated into pgrep's, pkill's, or pidwait's own
97 session ID.
98 -t, --terminal term,...
100 Only match processes whose controlling terminal is listed. The
101 terminal name should be specified without the "/dev/" prefix.
102 -u, --euid euid,...
104 Only match processes whose effective user ID is listed. Either
105 the numerical or symbolical value may be used.
106 -U, --uid uid,...
108 Only match processes whose real user ID is listed. Either the
109 numerical or symbolical value may be used.
110 -v, --inverse
112 Negates the matching. This option is usually used in pgrep's or
113 pidwait's context. In pkill's context the short option is dis‐
114 abled to avoid accidental usage of the option.
115 -w, --lightweight
117 Shows all thread ids instead of pids in pgrep's or pidwait's
118 context. In pkill's context this option is disabled.
119 -x, --exact
121 Only match processes whose names (or command lines if -f is
122 specified) exactly match the pattern.
123 -F, --pidfile file
125 Read PIDs from file. This option is more useful for pkill or
126 pidwait than pgrep.
127 -L, --logpidfile
129 Fail if pidfile (see -F) not locked.
130 -r, --runstates D,R,S,Z,...
132 Match only processes which match the process state.
133 -A, --ignore-ancestors
135 Ignore all ancestors of pgrep, pkill, or pidwait. For example,
136 this can be useful when elevating with sudo or similar tools.
137 -H, --require-handler
139 Only match processes with a userspace signal handler present for
140 the signal to be sent.
141 --cgroup name,...
143 Match on provided control group (cgroup) v2 name. See cgroups(8)
144 --ns pid
146 Match processes that belong to the same namespaces. Required to
147 run as root to match processes from other users. See --nslist
148 for how to limit which namespaces to match.
149 --nslist name,...
151 Match only the provided namespaces. Available namespaces: ipc,
152 mnt, net, pid, user, uts.
153 -q, --queue value
155 Use sigqueue(3) rather than kill(2) and the value argument is
156 used to specify an integer to be sent with the signal. If the
157 receiving process has installed a handler for this signal using
158 the SA_SIGINFO flag to sigaction(2), then it can obtain this
159 data via the si_value field of the siginfo_t structure.
160 -V, --version
162 Display version information and exit.
163 -h, --help
165 Display help and exit.
166
168 pattern
169 Specifies an Extended Regular Expression for matching against
170 the process names or command lines.
171
173 Example 1: Find the process ID of the named daemon:
174 $ pgrep -u root named
176 Example 2: Make syslog reread its configuration file:
178 $ pkill -HUP syslogd
180 Example 3: Give detailed information on all xterm processes:
182 $ ps -fp $(pgrep -d, -x xterm)
184 Example 4: Make all chrome processes run nicer:
186 $ renice +4 $(pgrep chrome)
188
190 0 One or more processes matched the criteria. For pkill and pid‐
191 wait, one or more processes must also have been successfully
192 signalled or waited for.
193 1 No processes matched or none of them could be signalled.
194 2 Syntax error in the command line.
195 3 Fatal error: out of memory etc.
196
198 The process name used for matching is limited to the 15 characters
199 present in the output of /proc/pid/stat. Use the -f option to match
200 against the complete command line, /proc/pid/cmdline. Threads may not
201 have the same process name as the parent process but will have the same
202 command line.
203 The running pgrep, pkill, or pidwait process will never report itself
205 as a match.
206 The -O --older option will silently fail if /proc is mounted with the
208 subset=pid option.
209
211 The options -n and -o and -v can not be combined. Let me know if you
212 need to do this.
213 Defunct processes are reported.
215 pidwait requires the pidfd_open(2) system call which first appeared in
217 Linux 5.3.
218
220 ps(1), regex(7), signal(7), sigqueue(3), killall(1), skill(1), kill(1),
221 kill(2), cgroups(8).
222
224 Kjetil Torgrim Homme ⟨kjetilho@ifi.uio.no⟩
225
227 Please send bug reports to ⟨procps@freelists.org⟩
228procps-ng 2023-01-16 PGREP(1)