skill, snice — send a signal or report process status


skill [signal] [options] expression
snice [new priority] [options] expression


These tools are obsolete and unportable.  The command syntax is poorly defined.  Consider using the killall, pkill, and pgrep commands instead.

The default signal for skill is TERM.  Use -l or -L to list available signals.  Particularly useful signals include HUP, INT, KILL, STOP, CONT, and 0.  Alternate signals may be specified in three ways: -9 -SIGKILL -KILL.

The default priority for snice is +4.  Priority numbers range from +20 (slowest) to -20 (fastest).  Negative priority numbers are restricted to administrative users.



Fast mode.  This option has not been implemented.


Interactive use.  You will be asked to approve each action.


List all signal names.


List all signal names in a nice table.


No action; perform a simulation of events that would occur but do not actually change the system.


Verbose; explain what is being done.


Enable warnings.  This option has not been implemented.

-h, --help

Display help text and exit.

-V, --version

Display version information.

Process Selection Options

Selection criteria can be: terminal, user, pid, command.  The options below may be used to ensure correct interpretation.

-t, --tty tty

The next expression is a terminal (tty or pty).

-u, --user user

The next expression is a username.

-p, --pid pid

The next expression is a process ID number.

-c, --command command

The next expression is a command name.

--ns pid

Match the processes that belong to the same namespace as pid.

--nslist ns,...

list which namespaces will be considered for the --ns option. Available namespaces: ipc, mnt, net, pid, user, uts.


The behavior of signals is explained in signal(7) manual page.


snice -c seti -c crack +7

Slow down seti and crack commands.

skill -KILL -t /dev/pts/*

Kill users on PTY devices.

skill -STOP -u viro -u lm -u davem

Stop three users.

See Also

kill(1), kill(2), killall(1), nice(1), pkill(1), renice(1), signal(7)


No standards apply.


Albert Cahalan wrote skill and snice in 1999 as a replacement for a non-free version.

Reporting Bugs

Please send bug reports to

Referenced By


The man page snice(1) is an alias of skill(1).

October 2011 procps-ng