Running a PHP "exec()" in the background on Windows?

Question

I've created a script that uses psexec to call another script which calls psexec to run a command line program of mine.

The reason for so many calls to psexec and other scripts is solely so that my PHP script doesn't have to wait for the process to finish before finishing it's output to the browser.

Is there a way I can do this without needing to use psexec? I'm having issues with psexec so I'd like to just completely remove it from my program.

I'm running Windows 2008

EDIT: I changed the title, I guess this would be a more accurate title. I found out the If a program is started with this function, in order for it to continue running in the background, the output of the program must be redirected to a file or another output stream. Failing to do so will cause PHP to hang until the execution of the program ends. on php.net's page on exec(), but wasn't sure how to do that.

Solution 1

Include a redirection in the command line:

exec('program.exe > NUL')

or you could modify your program to explicitly close standard output, in C this would be

CloseHandle(GetStdHandle(STD_OUTPUT_HANDLE));

It is possible (the documentation doesn't say) that you might need to redirect/close both the standard output and standard error:

exec('program.exe > NUL 2> NUL')

or

CloseHandle(GetStdHandle(STD_OUTPUT_HANDLE));
CloseHandle(GetStdHandle(STD_ERROR_HANDLE));

Solution 2

$command = 'start /B program.exe  > NUL';
pclose( popen( $command, 'r' ) );

For more info: http://humblecontributions.blogspot.com/2012/12/how-to-run-php-process-in-background.html

Solution 3

Try the Windows 'start' command: http://technet.microsoft.com/en-us/library/cc770297%28WS.10%29.aspx

Comments

[Rob]

If I try using start from exec(), won't I still need to wait for that process to finish before the PHP script will finish?

[Boann]

@Rob Oh sorry, I tried it and you're absolutely right. That's odd. I really thought it started independently.

[Jerry Saravia]

If you use popen( 'start command', 'r' ) on windows then it WON'T wait for the command to finish. Just found this out a few days ago.

[Damian]

like php.net/manual/en/function.popen.php here? the Example #2 popen() example , this is what you say??