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Name

skill, snice - send a signal or report process status

Synopsis

skill [signal to send] [options] process selection criteria snice [new priority] [options] process selection criteria

Description

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

General Options

-f fast mode This is not currently useful. -i interactive use You will be asked to approve each action.
-v verbose output Display information about selected processes.
-w warnings enabled This is not currently useful. -n no action This only displays the process ID. -V show version Displays version of program.

Process Selection Options

Selection criteria can be: terminal, user, pid, command. The options below may be used to ensure correct interpretation. Do not blame Albert for this interesting interface.

-t
The next argument is a terminal (tty or pty).
-u
The next argument is a username.
-p
The next argument is a process ID number.
-c
The next argument is a command name.

Signals

The signals listed below may be available for use with skill. When known, numbers and default behavior are shown.

Name Num Action Description

()
()

0
0 n/a exit code indicates if a signal may be sent
ALRM
14 exit
HUP
1 exit
INT
2 exit
KILL
9 exit this signal may not be blocked
PIPE
13 exit
POLL
exit
PROF
exit
TERM
15 exit
USR1
exit

USR2
exit
VTALRM
exit
STKFLT
exit may not be implemented
PWR
ignore may exit on some systems
WINCH
ignore
CHLD
ignore
URG
ignore
TSTP
stop may interact with the shell
TTIN
stop may interact with the shell
TTOU
stop may interact with the shell
STOP
stop this signal may not be blocked
CONT
restart continue if stopped, otherwise ignore
ABRT
6 core
FPE
8 core
ILL
4 core
QUIT
3 core
SEGV
11 core
TRAP
5 core
SYS
core may not be implemented
EMT
core may not be implemented
BUS
core core dump may fail
XCPU
core core dump may fail
XFSZ
core core dump may fail

Examples

Command
Description
snice seti crack +7
Slow down seti and crack
skill -KILL -v /dev/pts/* Kill users on new-style PTY devices
skill -STOP viro lm davem Stop 3 users
snice -17 root bash
Give priority to root’s shell

See Also

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

Standards

No standards apply.

Author

Albert Cahalan <albert@users.sf.net> wrote skill and snice in 1999 as a replacement for a non-free version, and is the current maintainer of the procps collection. Please send bug reports to <procps-feedback@lists.sf.net>.

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