multiproc test

multiproc.bash

#!/usr/bin/env bash

if [[ ${!KSH_VERSION} == .sh.version ]]; then
    if builtin getconf; builtin pids; then
        function BASHPID.get { .sh.value=$(pids -f '%(pid)d'); }
    elif [[ -r /proc/self/stat ]]; then
        function BASHPID.get { read -r .sh.value _ </proc/self/stat; }
    else
        function BASHPID.get { .sh.value=$(exec sh -c 'echo $PPID'); }
    fi 2>/dev/null
elif [[ ${BASH_VERSION+_} ]]; then
    shopt -s lastpipe extglob
elif [[ ! ${BASHPID+_} ]]; then
    echo 'BASHPID requires Bash, ksh93, or mksh >= R41' >&2
    exit 1
fi

function f {
    printf '%d: sleeping %d sec\n' "${@:1:2}"
    sleep "$2"
    printf '%d: returning %d\n' "$1" "$3"
    return "$3"
} >&2

function main {
    typeset -i n j maxj=$(getconf _NPROCESSORS_ONLN)
    trap '((j--))' CHLD
    set -m

    while ((n++ < 30)); do
        f "$BASHPID" $(((RANDOM % 5) + 1)) $((RANDOM % 2)) &
        ((++j >= maxj)) && POSIXLY_CORRECT= wait
    done

    echo 'finished, waiting for remaining jobs...' >&2
    wait
}

main "$@"
echo

# vim: set fenc=utf-8 ff=unix ft=sh :