SKILL
Section: Linux User's Manual (1)
Updated: March 12, 1999
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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
These tools are probably 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. (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.
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| -w | warnings enabled | This is not currently useful.
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| -n | no action | This only displays the process ID.
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| -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).
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| -u | The next argument is a username.
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| -p | The next argument is a process ID number.
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| -c | The next argument is a command name.
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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
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| ALRM | 14 | exit |
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| HUP | 1 | exit |
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| INT | 2 | exit |
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| KILL | 9 | exit | this signal may not be blocked
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| PIPE | 13 | exit |
|
| POLL | | exit |
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| PROF | | exit |
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| TERM | 15 | exit |
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| USR1 | | exit |
|
| USR2 | | exit |
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| VTALRM | | exit |
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| STKFLT | | exit | may not be implemented
|
| PWR | | ignore | may exit on some systems
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| WINCH | | ignore |
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| CHLD | | ignore |
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| URG | | ignore |
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| TSTP | | stop | may interact with the shell
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| TTIN | | stop | may interact with the shell
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| TTOU | | stop | may interact with the shell
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| STOP | | stop | this signal may not be blocked
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| CONT | | restart | continue if stopped, otherwise ignore
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| ABRT | 6 | core |
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| FPE | 8 | core |
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| ILL | 4 | core |
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| QUIT | 3 | core |
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| SEGV | 11 | core |
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| TRAP | 5 | core |
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| SYS | | core | may not be implemented
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| EMT | | core | may not be implemented
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| BUS | | core | core dump may fail
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| XCPU | | core | core dump may fail
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| 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>.