Apache下的PHP exec（）在运行脚本时返回null和255

Question

Ok, after having bashed my head on this for hours I decided to ask for help. I have a Windows Server 2008 running Apache 2.4 and PHP 7.1. My application must run a PHP script on the server when the user clicks a button on the browser.

This is working fine on my desktop with Windows 10. However, on the server, exec() returns "null" and an exit code of 255.

I read all I could find on exec() issues and tried the following:

exec("C:\\PHP7\\php.exe -v", $output);

I got the proper response containing PHP's version information.

Then I decided to check the configuration files:

exec("C:\\PHP7\\php.exe --ini", $output);

All files were in place.

Then I decided to perform a syntax check on my script:

exec("C:\\PHP7\\php.exe -d display_errors=1 -l C:\\Apache24\\htdocs\\script.php", $output);

No errors were found.

Finally I decided to check the user account:

exec("whoami", $output);

Got "NT Authority\\SYSTEM" as expected. To make sure that the script was able to run under the SYSTEM account I used SysInternals psexec:

psexec -s C:\PHP7\php.exe C:\Apache24\htdocs\script.php

Everything ran smoothly.

In other words, the script shows no problems when executed from the command line, either under a user account or the system account. I have also proven that PHP is being properly invoked by exec().

So, then I decided to check for "hidden" errors in my code adding the following two lines to the very beginning of the script:

error_reporting(E_ALL);
ini_set('display_errors', 1);

But, no joy. And I'm out of ideas.

Can any good soul help me on this?

Thanks a bunch,

Miguel.

Answer 1

Finally! The key to the answer was here: PHP exec() git fetch failing with return value 255 .

I was unable to see any errors, even adding the "2>&1" pipe redirection to my commands. After reading that article, I learned that proc_open() is way better than exec(). Quoting from PHP's documentation:

proc_open() is similar to popen() but provides a much greater degree of control over the program execution

So, I replaced my exec() for a few lines of code (refer to the example in the manual) and found that the problem was being caused by the Zend Opcache, which was enabled for CLI. The quickier solution for me was to disable it in the command line:

php.exe -d opcache.enable_cli=0 myscript.php

Voilà! Problem solved!