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SKILL(1) User Commands SKILL(1)


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.
Display help text and exit.
Display version information.


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

The next expression is a terminal (tty or pty).
The next expression is a username.
The next expression is a process ID number.
The next expression is a command name.
Match the processes that belong to the same namespace as pid.
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.


+Slow down seti and crack commands.
Kill users on PTY devices.
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

2023-08-19 procps-ng