mirror of
https://github.com/rawiriblundell/wiki.bash-hackers.org
synced 2024-12-26 06:20:41 +01:00
71 lines
3.4 KiB
Markdown
71 lines
3.4 KiB
Markdown
|
# The kill builtin command
|
||
|
|
|
||
|
|
## Synopsis
|
||
|
|
|
||
|
|
kill [-s SIGNAL | -n SIGNALNUMBER | -SIGNAL] PID|JOB
|
||
|
|
|
||
|
|
kill -l|-L [SIGNAL...]
|
||
|
|
|
||
|
|
## Description
|
||
|
|
|
||
|
|
The `kill` command is used to send signals to processes specified by
|
||
|
|
their `PID` or their `JOB`-specification.
|
||
|
|
|
||
|
|
The signal(s) to be specified can have the following formats:
|
||
|
|
|
||
|
|
- Numerical: The signal is specified using its constant numeric value.
|
||
|
|
Be aware that not all systems have identical numbers for the signals.
|
||
|
|
- Symbolic (long): The signal is specified using the same name that is
|
||
|
|
used for the constant/macro in the C API (`SIG<name>`)
|
||
|
|
- Symbolic (short): The signal is specified using the name from the C
|
||
|
|
API without the `SIG`-prefix (`<name>`)
|
||
|
|
|
||
|
|
Without any specified signal, the command sends the `SIGTERM`-signal.
|
||
|
|
|
||
|
|
The `kill` command is a Bash builtin command instead of relying on the
|
||
|
|
external `kill` command of the operating system to
|
||
|
|
|
||
|
|
- be able to use shell job specifications instead of Unix process IDs
|
||
|
|
- be able to send signals ("kill something") also, when your process
|
||
|
|
limit is reached
|
||
|
|
|
||
|
|
### Options
|
||
|
|
|
||
|
|
| Option | Description |
|
||
|
|
|:------------------|:------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|
||
|
|
| `-s SIGNAL` | specifies the signal to send |
|
||
|
|
| `-n SIGNALNUMBER` | specifies the signal to send |
|
||
|
|
| `-SIGNAL` | specifies the signal to send |
|
||
|
|
| `-l [SIGNAL...]` | Lists supported/known signal numbers and their symbolic name. If `SIGNAL` is given, only list this signal, translated (if a number is given the symbolic name is printed, and vice versa) |
|
||
|
|
| `-L [SIGNAL...]` | Same as `-l [SIGNAL]` (compatiblity option) |
|
||
|
|
|
||
|
|
### Return status
|
||
|
|
|
||
|
|
| Status | Reason |
|
||
|
|
|:-------|:----------------------------------------------------------------------------------------------------|
|
||
|
|
| 0 | no error/success |
|
||
|
|
| !=0 | invalid option |
|
||
|
|
| !=0 | invalid signal specification |
|
||
|
|
| !=0 | error returned by the system function (e.g. insufficient permissions to send to a specific process) |
|
||
|
|
|
||
|
|
## Examples
|
||
|
|
|
||
|
|
### List supported signals
|
||
|
|
|
||
|
|
kill -l
|
||
|
|
|
||
|
|
### Send KILL to a process ID
|
||
|
|
|
||
|
|
kill -9 12345
|
||
|
|
|
||
|
|
kill -KILL 12345
|
||
|
|
|
||
|
|
kill -SIGKILL 12345
|
||
|
|
|
||
|
|
## Portability considerations
|
||
|
|
|
||
|
|
- POSIX(R) and ISO C only standardize symbolic signal names (no numbers)
|
||
|
|
and a default action
|
||
|
|
|
||
|
|
## See also
|