php shell_exec return null

Question

I want run php ../cat1/index.php gr_s2/3/gr-n40 1200 command by php. The shell_exec return NULL as result but when I try that command on cmd, output was shown correctly.

What happen in php and shell_exec ?!

Note: The command with different parameters (Like: php ../cat1/index.php gr_s2/3/gr-n40 800) works correctly in both (php and cmd).

Can you add 2>&1 and the end of the line and check again? – sergio Jan 06 '16 at 08:48 — sergio, Jan 06 '16 at 08:48
dear @sergio, Nup! not worked! – Masoud Nazari Jan 06 '16 at 08:52 — Masoud Nazari, Jan 06 '16 at 08:52

shozdeh · Accepted Answer · 2016-01-06T22:29:10.383

3

There is a note in php manual page of shell_execute:

Note: This function can return NULL both when an error occurs or the program produces no output. It is not possible to detect execution failures using this function. exec() should be used when access to the program exit code is required.

Source: http://php.net/manual/en/function.shell-exec.php

So your code running with error. Try with exec. If you want, insert your code (or blocks) to be checked.

edited Jan 06 '16 at 22:29

answered Jan 06 '16 at 21:23

shozdeh

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Dear @shozdeh, I tried with exec() method an got same resutl...! There is no error in code. – Masoud Nazari Jan 07 '16 at 08:14
@MasoudNazari check run time limit or memory limit is not reached?! – shozdeh Jan 08 '16 at 10:00

score 0 · Answer 2 · answered Sep 21 '17 at 10:35

This is fixed by adding user used by web-server to sudoer and run the php command with

sudo php ..........

To start run this command sudo visudo

Add the following line at the end of sudoer file opened

www-data ALL=NOPASSWD: /usr/bin/php

But if you whant to execute all commad from php add this line instead of the above www-data ALL=NOPASSWD: ALL which is not recommended

and the run your commands with sudo php /path/to/you/file.php

For my case I was running ubuntu 14.04

Have fun please

I am facing the same problem when I am executing external exe. Windows don't have sudo command — Prashant, Apr 30 '18 at 19:26

php shell_exec return null

2 Answers2