PHP Unconference Europe 2015

proc_terminate

(PHP 5)

proc_terminateKills a process opened by proc_open

Description

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

Signals a process (created using proc_open()) that it should terminate. proc_terminate() returns immediately and does not wait for the process to terminate.

proc_terminate() allows you terminate the process and continue with other tasks. You may poll the process (to see if it has stopped yet) by using the proc_get_status() function.

Parameters

process

The proc_open() resource that will be closed.

signal

This optional parameter is only useful on POSIX operating systems; you may specify a signal to send to the process using the kill(2) system call. The default is SIGTERM.

Return Values

Returns the termination status of the process that was run.

Changelog

Version Description
5.2.2 Previous versions used to destroy the given process resource.

See Also

  • proc_open() - Execute a command and open file pointers for input/output
  • proc_close() - Close a process opened by proc_open and return the exit code of that process
  • proc_get_status() - Get information about a process opened by proc_open

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User Contributed Notes 3 notes

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6
jerhee at ucsd dot edu
6 years ago
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);
}

?>
up
1
v dot denegin at yahoo dot com
10 months ago
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);
up
1
csh dot spam at me dot com
1 year ago
/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".
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