Bash & (ampersand) operator

bash background-process exit-code
Misha Moroshko picture Misha Moroshko · Feb 13, 2012 · Viewed 27.3k times · Source

I'm trying to run 3 commands in parallel in bash shell:

$ (first command) & (second command) & (third command) & wait

The problem with this is that if first command fails, for example, the exit code is 0 (I guess because wait succeeds).

The desired behavior is that if one of the commands fails, the exit code will be non-zero (and ideally, the other running commands will be stopped).

How could I achieve this?

Please note that I want to run the commands in parallel!

Answer

Karoly Horvath picture Karoly Horvath · Feb 13, 2012

the best I can think of is:

first & p1=$!
second & p2=$!
...

wait $p1 && wait $p2 && ..

or

wait $p1 || ( kill $p2 $p3 && exit 1 )
...

however this still enforces an order for the check of processes, so if the third fails immediately you won't notice it until the first and second finishes.

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