PHP – 在客户端断开连接时杀死exec

这会导致PHP在生成内容时将输出刷新到客户端,这允许PHP检测客户端何时断开连接.当客户端立即断开连接并终止子进程时,PHP将终止(只要未设置ignore_user_abort()).

例：

<?php

  function exec_unix_bg ($cmd) {
    // Executes $cmd in the background and returns the PID as an integer
    return (int) exec("$cmd > /dev/null 2>&1 & echo $!");
  }
  function pid_exists ($pid) {
    // Checks whether a process with ID $pid is running
    // There is probably a better way to do this
    return (bool) trim(exec("ps | grep "^$pid ""));
  }

  $cmd = "/path/to/your/cpp arg_1 arg_2 arg_n";

  // Start the C++ program
  $pid = exec_unix_bg($cmd);

  // Ignore user aborts to allow us to dispatch a signal to the child
  ignore_user_abort(1);

  // Loop until the program completes
  while (pid_exists($pid)) {

    // Push some harmless data to the client
    echo " ";
    flush();

    // Check whether the client has disconnected
    if (connection_aborted()) {
      posix_kill($pid,SIGTERM); // Or SIGKILL,or whatever
      exit;
    }

    // Could be done better? Only here to prevent runaway CPU
    sleep(1);

  }

  // The process has finished. Do your thang here.

要收集程序的输出,请将输出重定向到文件而不是/ dev / null.我怀疑你需要安装pcntl以及posix,因为PHP手册表明SIGxxx常量是由pcntl扩展定义的 – 尽管我没有安装过没有其他的,所以我不确定.