Stupid Tricks: bash
November 12, 2012This article showcases a few stupid bash tricks that I've gathered in my recent employment as a unix sysadmin. Some of these aren't all that useful, but they are neat.
First up, a fun toy:
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| for i in {1..100}; do | |
| echo -ne "\r$i" | |
| sleep .5 | |
| done | |
| echo |
Running this, you'll see a counter that rises from 1 to 100, overwriting itself as it goes. You could use this with some trickery to give a visual indicator of how far done a process is, for example.
Next up, returning a value from a function:
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| function hello-world { | |
| local __resultvar=$1 | |
| local __blah="Hello, world!" | |
| eval $__resultvar="'$__blah'" | |
| } | |
| hello-world foo | |
| echo $foo |
You can scale this to return as many values as you want from a function.
I use this one all the time.
Concatenate strings:
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| a="hello" | |
| b="world" | |
| c=$a" there, isn't it a wonderful "$b"?" | |
| echo $c |
It really is as simple as mushing them together like that.
That's all for now. Thanks, for reading!