在后台运行脚本并从php返回其pid

Question

I try to invoke an app inside php:

ob_start();
passthru("(cd /opt/server/TrackServer/release && ./TrackServer& ) && pidof TrackServer");
$pid = ob_get_clean();
var_dump($pid);
exit;

The goal is to run TrackServer within its path and to get it's process id so I can close it after I do some test.

When I run the command in terminal:

(cd /opt/server/TrackServer/release && nohup ./TrackServer&) && pidof TrackServer

I get correct pid returned but in php the command stops and doesn't go further, the TrackServer is started and running but I have to kill it from terminal to unblock the php script, after killing the process the php script prints the correct pid for the process I've just closed from terminal.

1. Why the command stops?

2. Is there a way to make it run in php the way I'am trying to run it (without forking to a new thread)?

Answer 1

EDIT: I found a working solution:

ob_start();
passthru("/bin/bash -c 'cd /opt/server/TrackServer/release && nohup ./TrackServer&' > /dev/null 2>&1 &");
passthru("pidof TrackServer");
$pid = ob_get_clean();

The command was stopping because:

Run multiple exec commands at once (But wait for the last one to finish)

PHP's exec function will always wait for a response from your execution. However you can send the stdout & stderror of the process to /dev/null (on unix) and have these all the scripts executed almost instantly.