halt_future_tasks_on_fail.sh

#!/bin/bash
FAILURE=0

do_tasks() {
        if [[ $FAILURE -eq 0 ]]; then
                echo -e "Running tasks\n"

                some_command &
                some_command &
                some_command &
        else
                echo -e "A task failed. Halting future calls.\n"
        fi
}

waitall() {
        while true; do
                pids=`jobs -p`
                if [[ "$pids" == "" ]]; then break; fi

                for pid in $pids; do
                        if kill -0 $pid 2> /dev/null; then
                                continue;
                        elif wait $pid; then
                                continue;
                        else
                                FAILURE=1
                        fi
                done
        done
}

do_tasks;

waitall;

do_tasks;