Question

我想要一个php脚本，我可以从中执行程序，如果它在2秒内没有完成执行，则终止它。我正在使用Windows。我尝试了以下代码：

exec("start /B program.exe");
sleep(2);
exec('taskkill /F /IM "program.exe"');

这似乎不起作用，因为只要exec未完成执行，脚本就会停留在第一个program.exe语句上。我无法弄清楚如何解决这个问题。

Answer 1

是的，exec()将阻止，直到执行完成。 This question对于如何在超时时间内执行exec()有很好的答案。我认为this可能最适合你。我会在此处发布完整代码（但我无法承担任何责任！）：

/**
 * Execute a command and return it's output. Either wait until the command exits or the timeout has expired.
 *
 * @param string $cmd     Command to execute.
 * @param number $timeout Timeout in seconds.
 * @return string Output of the command.
 * @throws \Exception
 */
function exec_timeout($cmd, $timeout) {
  // File descriptors passed to the process.
  $descriptors = array(
    0 => array('pipe', 'r'),  // stdin
    1 => array('pipe', 'w'),  // stdout
    2 => array('pipe', 'w')   // stderr
  );

  // Start the process.
  $process = proc_open('exec ' . $cmd, $descriptors, $pipes);

  if (!is_resource($process)) {
    throw new \Exception('Could not execute process');
  }

  // Set the stdout stream to none-blocking.
  stream_set_blocking($pipes[1], 0);

  // Turn the timeout into microseconds.
  $timeout = $timeout * 1000000;

  // Output buffer.
  $buffer = '';

  // While we have time to wait.
  while ($timeout > 0) {
    $start = microtime(true);

    // Wait until we have output or the timer expired.
    $read  = array($pipes[1]);
    $other = array();
    stream_select($read, $other, $other, 0, $timeout);

    // Get the status of the process.
    // Do this before we read from the stream,
    // this way we can't lose the last bit of output if the process dies between these     functions.
    $status = proc_get_status($process);

    // Read the contents from the buffer.
    // This function will always return immediately as the stream is none-blocking.
    $buffer .= stream_get_contents($pipes[1]);

    if (!$status['running']) {
      // Break from this loop if the process exited before the timeout.
      break;
    }

    // Subtract the number of microseconds that we waited.
    $timeout -= (microtime(true) - $start) * 1000000;
  }

  // Check if there were any errors.
  $errors = stream_get_contents($pipes[2]);

  if (!empty($errors)) {
    throw new \Exception($errors);
  }

  // Kill the process in case the timeout expired and it's still running.
  // If the process already exited this won't do anything.
  proc_terminate($process, 9);

  // Close all streams.
  fclose($pipes[0]);
  fclose($pipes[1]);
  fclose($pipes[2]);

  proc_close($process);

  return $buffer;
}

修改

＆＃39; exec＆＃39;部分proc_open()可能无法在Windows上运行，但可能没必要。

Answer 2

您是否使用php cli (command line)执行此操作？打开command prompt as administrator 要等待程序close the process of opening the program不被阻止。

php myscript.php

pclose(popen("start /B program.exe", "r"));
sleep(2);
exec('taskkill /F /IM program.exe');
exit(0);

将 exec start 放入单独的脚本并使用exec

启动此脚本也可以。

Answer 3

exec()手册页的first comment显示了一个非常简单的示例。

即使在Windows上的backgroud中运行命令后，PHP脚本也停留在exec上

3 个答案: