run a command with a timeout

gistfile1.sh

# Prefer the timeout program from GNU coreutils.
if command -v timeout > /dev/null 2>&1; then
    :
elif command -v gtimeout > /dev/null 2>&1; then
    timeout () {
        gtimeout $@
    }
else
    # From "Beginning Portable Shell Scripting", 2008.
    timeout () {
        timeout=$1
        shift
        "$@" &
        child_pid=$!
        (
            trap 'kill -TERM $sleep_pid 2>/dev/null ; exit 0' TERM
            sleep "$timeout" &
            sleep_pid=$!
            wait $sleep_pid 2>/dev/null
            kill -TERM $child_pid 2>/dev/null
            sleep 2
            kill -KILL $child_pid 2>/dev/null
        ) &
        alarm_pid=$!
        wait $child_pid 2>/dev/null
        status=$?
        kill -TERM $alarm_pid 2>/dev/null
        return $status
    }
fi