#!/bin/sh

usage() {
    printf "Usage: %s [-v] [-h] [-t TIMEOUT] [-c COMMAND]\n\n" "$0"
}

help() {
    cat << EOH
 SYNOPSIS
    $0 [-v] [-h] [-t TIMEOUT] [-c COMMAND]

 DESCRIPTION

    \`Timeout\` executes a command until the timeout is over.
    When the command is finished before the timeout then the exit code is \`0\` else it's \`1\`.

 OPTIONS

    -h    Show this help

    -v    Display  the command output (stderr)

    -c COMMAND
          The command to execute
          \`COMMAND=... $0\` works to.

    -t TIMEOUT
          The timeout in seconds (default: 10)
          \`TIMEOUT=... $0\` works to.
EOH
}

on_interrupt() {
    print "Process aborted!\n"

    exit 130
}

create_script() {
    printf "#!/bin/sh\n%s\n" "$1" > "$2"
    chmod +x "$SCRIPT_FILE"
}

run_script() {
    if [ "$2" -eq 0 ]; then
        "$SCRIPT_FILE" >/dev/null 2>&1 &
    else
        "$SCRIPT_FILE" >&2 &
    fi

    printf "%d" $!
}

stop_delete_script() {
    kill -9 "$1"
    rm -f "$2"
}

check_pid() {
    PID=$1
    LOOP=$2

    for _ in $(seq 1 "$((LOOP*2))"); do
        test -d "/proc/$PID/" && sleep 0.5 || STATUS=0
    done

    printf "%d" ${STATUS:-1}
}

main() {
    while getopts "ht:c:v" option; do
        case "${option}" in
            h) help; exit 0;;
            t) TIMEOUT="$OPTARG";;
            c) COMMAND="$OPTARG";;
            v) VERBOSE=1;;
            *) usage; exit 1;;
        esac
    done

    TIMEOUT="${TIMEOUT:-10}"
    VERBOSE="${VERBOSE:-0}"

    if [ -z "$COMMAND" ]; then
        printf "Command is required!\n"
        exit 1
    fi

    SCRIPT_FILE="$(mktemp)"

    create_script "$COMMAND" "$SCRIPT_FILE"

    SCRIPT_PID=$(run_script "$SCRIPT_FILE" "$VERBOSE")
    EXIT_STATUS=$(check_pid "$SCRIPT_PID" "$TIMEOUT")

    stop_delete_script "$SCRIPT_PID" "$SCRIPT_FILE"

    exit "$EXIT_STATUS"
}

trap on_interrupt INT

main "$@"