What is /dev/null in shell command ? various types of arguments /dev/null argumentargument description> /dev/nullthrow away stdout1> /dev/nullthrow away stdout2
various types of arguments /dev/null
argument | argument description |
---|---|
> /dev/null |
throw away stdout |
1> /dev/null |
throw away stdout |
2> /dev/null |
throw away stderr |
&> /dev/null |
throw away both stdout and stderr |
>
is the operator used to redirect output. 2
is a reference to the standard error output stream, i.e. 2>
= redirect error output.
/dev/null
is the 'null device' which just swallows any input provided to it. You can combine the two to effectively throw away output from a command.
Usages /dev/null example
Suppress rm
warnings
$ rm tempfl.txt 2> /dev/null
Redirect script output to /dev/null
$ ./myscript.sh 2> /dev/null
The latter has a drawback of missing all other warning messages produced by your script.
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