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66 lines
2.2 KiB
Plaintext
66 lines
2.2 KiB
Plaintext
====== The kill builtin command ======
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===== Synopsis =====
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<code>kill [-s SIGNAL | -n SIGNALNUMBER | -SIGNAL] PID|JOB</code>
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<code>kill -l|-L [SIGNAL...]</code>
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===== Description =====
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The ''kill'' command is used to send signals to processes specified by their ''PID'' or their ''JOB''-specification.
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The signal(s) to be specified can have the following formats:
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* Numerical: The signal is specified using its constant numeric value. Be aware that not all systems have identical numbers for the signals.
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* Symbolic (long): The signal is specified using the same name that is used for the constant/macro in the C API (''SIG<name>'')
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* Symbolic (short): The signal is specified using the name from the C API without the ''SIG''-prefix (''<name>'')
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Without any specified signal, the command sends the ''SIGTERM''-signal.
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The ''kill'' command is a Bash builtin command instead of relying on the external ''kill'' command of the operating system to
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* be able to use shell job specifications instead of Unix process IDs
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* be able to send signals ("kill something") also, when your process limit is reached
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==== Options ====
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^Option ^Description ^
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|''-s SIGNAL'' |specifies the signal to send |
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|''-n SIGNALNUMBER'' |specifies the signal to send |
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|''-SIGNAL'' |specifies the signal to send |
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|''-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) |
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|''-L [SIGNAL...]'' |Same as ''-l [SIGNAL]'' (compatiblity option) |
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==== Return status ====
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^Status ^Reason ^
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|0 |no error/success |
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|!=0 |invalid option |
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|!=0 |invalid signal specification |
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|!=0 |error returned by the system function (e.g. insufficient permissions to send to a specific process) |
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===== Examples =====
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==== List supported signals ====
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<code>
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kill -l
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</code>
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==== Send KILL to a process ID ====
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<code>
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kill -9 12345
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</code>
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<code>
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kill -KILL 12345
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</code>
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<code>
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kill -SIGKILL 12345
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</code>
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===== Portability considerations =====
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* POSIX(R) and ISO C only standardize symbolic signal names (no numbers) and a default action
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===== See also =====
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