Guide to Unix/Commands/Process Management
nohup
[edit | edit source]nohup lets you run a program in a way which makes it ignore hangup signals. This can be used to make a program continue running after a user has logged out. The output of the program is redirected from the standard output to the file nohup.out.
Examples:
$ nohup wget http://foo.org/foo_list.gz nohup: appending output to `nohup.out' $
Links:
- nohup, opengroup.org
- nohup, freebsd.org
- 23.4 nohup in GNU Coreutils manual, gnu.org
ps
[edit | edit source]ps displays a list of current processes and their properties.
Examples:
Processes owned by the current user:
$ ps PID TTY TIME CMD 17525 pts/0 00:00:00 su 17528 pts/0 00:00:00 bash 17590 pts/0 00:00:00 ps where pid is process id.
All processes:
$ ps -A
Links:
- ps, opengroup.org
- ps man page, man.cat-v.org
kill
[edit | edit source]kill is used to send termination signals to processes.
Examples
To send the kill signal to the processes with process id 17525,
$ kill -9 17525
To send the kill signal to all processes,
$ kill -9 -1
see Guide to Unix/Commands/Process Management/Kill
Links:
- kill, opengroup.org
- kill man page, man.cat-v.org
- 24.1 kill in GNU Coreutils manual, gnu.org
pgrep
[edit | edit source]pgrep search and kill system processes
Example: Check if apache webserver is running.
$ pgrep -f apache 5580 5581 5582 5583 5584 5585 or $ svcs -a | grep -i apache.
Links:
pkill
[edit | edit source]Stop xterm program with 'pkill' program:
$ pkill -9 xterm
Tips: Display all the process of a user
$ pgrep -l -u arky 894 bash 895 bash 897 bash 898 bash 899 bash 1045 links 1396 startx 1407 xinit 1411 openbox 1412 xterm 1413 xfaces 1414 xsetroot 1415 emacs
Links:
pidof
[edit | edit source]pidof display Process ID (PID) of a task
Example: Display the PID of emacs process:
$ pidof emacs 1415
Links:
- pidof, manpages.ubuntu.com
killall
[edit | edit source]killall kill a process by name
Example:
Kill the 'xfaces' program:
$ killall xfaces
Links: