skill (1)

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.

-f,--fast

Fast mode. This option has not been implemented.

-i,--interactive

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

-l,--list

List all signal names.

-L,--table

List all signal names in a nice table.

-n,--no-action

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

-v,--verbose

Verbose; explain what is being done.

-w,--warnings

Enable warnings. This option has not been implemented.

-h, --help

Display help text and exit.

-V, --version

Display version information.

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.

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.

Please send bug reports to