Bash等待多个并发子进程并杀死所有错误

Question

I'm running a bash script with multiple simultaneous commands (python scripts). I'm trying to kill all the processes if one of them has failed. The thing is that the python scripts are still running in the background, and if one of them has failed, my bash script doesn't know about.

Here's a snippet from my script:

set -a
trap cleanup_children SIGTERM
MY_PID=$$

function thread_listener () {
    to_execute="$1"
    echo "Executing $to_execute ..."
    $to_execute &
    PID=$!
    trap 'echo killing $PID; kill $PID' SIGTERM
    echo "Waiting for $PID ($to_execute) ..."
    wait $PID || if `kill -0 $MY_PID &> /dev/null`; then kill $MY_PID; fi
}

function cleanup_children () {
    for job in `jobs -p`
    do
        if `kill -0 $job &> /dev/null`; then
            echo "Killing child number $job"
            ps -p $job
            kill $job
        fi
    done
}

function create_app1 () {
    cd ${GIT_DIR}
    python ./create-app.py -myapp
    exit_code=$?
    echo "Create app1 ISO result: ${exit_code}"
    [ "${exit_code}" == "1" ] && exit 1
    mv ${ISO_OUTPUT_DIR}/rhel-7.1.iso ${ISO_OUTPUT_DIR}/${ISO_NAME}.iso
}

function create_app2 () {
    cd ${GIT_DIR}
    python ./create-app.py -do-something
    exit_code=$?
    echo "Create app1 ISO result: ${exit_code}"
    [ "${exit_code}" == "1" ] && exit 1
    mv ${ISO_OUTPUT_DIR}/rhel-7.1.iso ${ISO_OUTPUT_DIR}/${ISO_NAME}.iso
}

export -f create_app1
export -f create_app2

echo "MY_PID=$MY_PID"
thread_listener create_app1 &
PID_APP1=$!

thread_listener create_app2 &
PID_APP2=$!
wait

kill $PID_APP1 2> /dev/null
kill $PID_APP2 2> /dev/null

Answer 1

Hm, this looks quite advanced ;). Do I assume correctly that you never see the "Create app1 ISO result" output then because the python script does not terminate? It might be an issue with the signal not being properly dispatched to bash background jobs. It might also be related to your python code not properly reacting to the signal. Have you checked out https://docs.python.org/2/library/signal.html ? Sure you'd have to figure out the exact steps how to interrupt you python code while executing. I'd suggest to first make sure that the python code reacts to signals the way you want.