How to wait in bash for several subprocesses to finish and return exit code !=0 when any subprocess ends with code !=0?

Question

How to wait in a bash script for several subprocesses spawned from that script to finish and return exit code !=0 when any of the subprocesses ends with code !=0 ?

S

Answer 1

I needed this, but the target process wasn't a child of current shell, in which case wait $PID doesn't work. I did find the following alternative instead:

while [ -e /proc/$PID ]; do sleep 0.1 ; done

That relies on the presence of procfs, which may not be available (Mac doesn't provide it for example). So for portability, you could use this instead:

while ps -p $PID >/dev/null ; do sleep 0.1 ; done