This post will guide you how to kill a process using kill, killall or pkill command from the command line in your Linux system. How do I find out the ID of a running process in Linux.
List All Running Processes
You can use “ps” command to list all the running processes on your current system, type:
$ ps aux
If you want to find out the ID of a particular running process, and you can use ps command and grep command, type:
$ ps aux | grep ProcessName $ ps aux | grep systemd
Outputs:
[devops@mydevops ~]$ ps aux | grep systemd
root 1 0.2 1.0 179120 13924 ? Ss 01:09 0:01 /usr/lib/systemd/systemd --switched-root --system --deserialize 18
root 601 0.0 0.6 93408 8936 ? Ss 01:09 0:00 /usr/lib/systemd/systemd-journald
root 634 0.0 0.8 117304 11104 ? Ss 01:09 0:00 /usr/lib/systemd/systemd-udevd
dbus 790 0.1 0.4 70824 6112 ? Ssl 01:09 0:00 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
root 798 0.0 0.5 82880 7052 ? Ss 01:09 0:00 /usr/lib/systemd/systemd-machined
root 871 0.0 0.7 95232 9568 ? Ss 01:09 0:00 /usr/lib/systemd/systemd-logind
gdm 956 0.0 0.7 93136 9596 ? Ss 01:09 0:00 /usr/lib/systemd/systemd --user
gdm 1016 0.0 0.3 81876 5332 ? Ssl 01:09 0:00 /usr/bin/dbus-daemon --session --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
devops 2190 0.0 0.7 93176 9596 ? Ss 01:12 0:00 /usr/lib/systemd/systemd --user
devops 2257 0.0 0.3 81424 4916 ? Ssl 01:12 0:00 /usr/bin/dbus-daemon --session --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
devops 2356 0.0 0.0 12112 1088 pts/0 R+ 01:20 0:00 grep --color=auto systemd
Kill a Process using kill Command
If you want to kill a running process(such as: httpd) at the shell prompt on your system, and you can use kill command. before killing a process, and you need to find out the ID of process using above command or another command called pidof. type:
$ pidof httpd
or
$ ps aux | grep httpd
or
$ pgrep httpd
Outputs:
[devops@mydevops ~]$ pidof httpd 3140 3137 3136 3135 3126 [devops@mydevops ~]$ ps aux | grep httpd root 3126 0.1 0.8 280224 11080 ? Ss 01:34 0:00 /usr/sbin/httpd -DFOREGROUND apache 3135 0.0 0.6 292440 8572 ? S 01:34 0:00 /usr/sbin/httpd -DFOREGROUND apache 3136 0.0 0.8 1350212 11884 ? Sl 01:34 0:00 /usr/sbin/httpd -DFOREGROUND apache 3137 0.0 1.0 1481348 13932 ? Sl 01:34 0:00 /usr/sbin/httpd -DFOREGROUND apache 3140 0.0 0.8 1350212 11880 ? Sl 01:34 0:00 /usr/sbin/httpd -DFOREGROUND devops 3356 0.0 0.0 12112 1072 pts/0 R+ 01:35 0:00 grep --color=auto httpd [devops@mydevops ~]$ pgrep httpd 3126 3135 3136 3137 3140
once you get process ID, and you can use the kill command to kill that process, type:
$ sudo kill -9 PID
Kill a Process using killall or pkill Command
You can also use killall or pkill command to kill process by name from the command line:
$ sudo killall -9 httpd
or
$ pkill -9 httpd
Conclusion
You should know that how to force terminate a process using kill/pkill/killall commands in your CentOS or RHEL or Ubuntu Linux system.