proc_terminate()

(PHP 5, PHP 7)

杀除由 proc_open 打开的进程

说明

proc_terminate(resource $process[,int $signal= 15]): bool

向$process（由proc_open()函数创建）发送信号通知其终止。proc_terminate()调用之后将会立即返回，而不会等待进程终止。

可以使用proc_terminate()终止进程并且继续其他的任务。可以使用proc_get_status()函数来检查进程是否已经终止。

参数

$process

由proc_open()打开的resource。

$signal

可选参数，仅用于POSIX操作系统。表示调用系统命令kill(2)来向进程发送的信号。默认值为SIGTERM。

返回值

返回进程的终止状态。

更新日志

参见

• proc_open() 执行一个命令，并且打开用来输入/输出的文件指针。
• proc_close() 关闭由 proc_open 打开的进程并且返回进程退出码
• proc_get_status() 获取由 proc_open 函数打开的进程的信息

/bin/sh -c CMD will fork sh and then exec CMD.
/bin/sh -c exec CMD will NOT fork and only executes CMD.
Therefore, you can get rid of this hack by prefixing your command to "exec bla bla bla".

As explained in http://bugs.php.net/bug.php?id=39992, proc_terminate() leaves children of the child process running. In my application, these children often have infinite loops, so I need a sure way to kill processes created with proc_open(). When I call proc_terminate(), the /bin/sh process is killed, but the child with the infinite loop is left running. 
Until proc_terminate() gets fixed, I would not recommend using it. Instead, my solution is to:
1) call proc_get_status() to get the parent pid (ppid) of the process I want to kill. 
2) use ps to get all pids that have that ppid as their parent pid
3) use posix_kill() to send the SIGKILL (9) signal to each of those child pids
4) call proc_close() on process resource
<?php
$descriptorspec = array(
0 => array('pipe', 'r'), // stdin is a pipe that the child will read from
1 => array('pipe', 'w'), // stdout is a pipe that the child will write to
2 => array('pipe', 'w')  // stderr is a pipe the child will write to
);
$process = proc_open('bad_program', $descriptorspec, $pipes);
if(!is_resource($process)) {
  throw new Exception('bad_program could not be started.');
}
//pass some input to the program
fwrite($pipes[0], $lots_of_data);
//close stdin. By closing stdin, the program should exit
//after it finishes processing the input
fclose($pipes[0]);
//do some other stuff ... the process will probably still be running
//if we check on it right away
$status = proc_get_status($process);
if($status['running'] == true) { //process ran too long, kill it
  //close all pipes that are still open
  fclose($pipes[1]); //stdout
  fclose($pipes[2]); //stderr
  //get the parent pid of the process we want to kill
  $ppid = $status['pid'];
  //use ps to get all the children of this process, and kill them
  $pids = preg_split('/\s+/', `ps -o pid --no-heading --ppid $ppid`);
  foreach($pids as $pid) {
    if(is_numeric($pid)) {
      echo "Killing $pid\n";
      posix_kill($pid, 9); //9 is the SIGKILL signal
    }
  }
    
  proc_close($process);
}
?>

on Windows platform proc_terminate() does not kill sub-processes that are not handling kill signals. It happens even if you call xxx.exe and call proc_terminate() the process will remain active.
The solution is instead of calling proc_terminate() is to call the user-defined kill() function (already win/unix optimized)
After that need to close all pipes and execute proc_close().
function kill($pid){ 
  return stripos(php_uname('s'), 'win')>-1 ? exec("taskkill /F /T /PID $pid") : exec("kill -9 $pid");
}
function killall($pids) { 
  $os=stripos(php_uname('s'), 'win')>-1;
  ($_=implode($os?' /PID ':' ',$pids)) or ($_=$pids);
  return preg_match('/success|close/', $os ? exec("taskkill /F /T /PID $_") : exec("kill -9 $_"));
}
Example:
$pstatus = proc_get_status($resource);
$PID = $pstatus['pid'];
// other commands
kill($PID); // instead of proc_terminate($resource);
fclose($pipes[0]); 
fclose($pipes[1]); 
fclose($pipes[2]);
proc_close($resource);