执行命令 x 秒？

Question

可能的重复：
运行命令指定时间，如果时间超过则中止

是否有一个命令允许我执行另一个命令最多 x 秒？

想象的例子：runonlyxseconds -s 5 <the real command and its args>

此后它将被强制终止（例如第一次发送SIGTERM，如果它不起作用，SIGKILL）。

谢谢

Answer 1

bash仅使用几乎通用的系统命令的纯粹解决方案：

timeout() {
    if (( $# < 3 )); then
        printf '%s\n' 'Usage: timeout sigterm-seconds sigkill-seconds command [arg ...]'
        return 1
    fi

    "${@:3}" &
    pid=$!

    sleep "$1"

    if ps "${pid}" >/dev/null 2>&1; then
        kill -TERM "${pid}"
        sleep "$2"
        if ! ps "${pid}" >/dev/null 2>&1; then
            printf '%s\n' "Process timed out, and was terminated by SIGTERM."
            return 2
        else
            kill -KILL "${pid}"
            sleep 1
            if ! ps "${pid}" >/dev/null 2>&1; then
                printf '%s\n' "Process timed out, and was terminated by SIGKILL."
                return 3
            else
                printf '%s\n' "Process timed out, but can't be terminated (SIGKILL ineffective)."
                return 4
            fi
        fi
    else
        printf '%s\n' "Process exited gracefully before timeout."
    fi
}

然后运行为timeout sigterm-seconds sigkill-seconds command [arg ...].