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

There can be a case where the process is complete before waiting for the process. If we trigger wait for a process that is already finished, it will trigger an error like pid is not a child of this shell. To avoid such cases, the following function can be used to find whether the process is complete or not:

isProcessComplete(){
PID=$1
while [ -e /proc/$PID ]
do
    echo "Process: $PID is still running"
    sleep 5
done
echo "Process $PID has finished"
}