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I've got a php script which has the line:

system("ffmpeg -i ......");

The output folder is set to be:

drwxrwxr-x  5 apache apache   4096 Oct 19 07:40 in_upload

If I run the exact text "ffmpeg -i ......" from the prompt as root, it works fine.

But if the script is run, only a zero sized file is created. Any ideas on what could be wrong?

Edit 1

I think I've localized the problem to selinux

I tried the solution recommended in :

function my_exec($cmd, $input='')
         {$proc=proc_open($cmd, array(0=>array('pipe', 'r'), 1=>array('pipe', 'w'), 2=>a$
          fwrite($pipes[0], $input);fclose($pipes[0]);
          return array('stdout'=>$stdout,

echo "1 ";
echo shell_exec('ls');
echo "\n2 ";
echo "\n3 ";


Output was:


Edit 2

AFTER disabling selinux, I got the following results:

echo "1 ";
echo shell_exec('ffmpeg');
echo "\n2 ";
echo system('ffmpeg');
echo "\n3 ";
echo exec('ffmpeg');
===> None worked

echo "1 ";
echo shell_exec('/usr/bin/ffmpeg');
echo "\n2 ";
echo system('/usr/bin/ffmpeg');
echo "\n3 ";
echo exec('/usr/bin/ffmpeg');
===> None worked

echo "1 ";
echo shell_exec('ls');
echo "\n2 ";
echo system('ls');
echo "\n3 ";
echo exec('ls');
===> All 3 worked as expected.

Edit 3

php script:

echo "1 ";
echo shell_exec('touch test1.txt');
echo "\n2 ";
echo system('touch test2.txt');
echo "\n3 ";
echo exec('touch test3.txt');


touch: cannot touch `test1.txt': Permission denied
touch: cannot touch `test2.txt': Permission denied
touch: cannot touch `test3.txt': Permission denied

php script:

echo "1 ";
echo shell_exec('/bin/touch test1.txt');
echo "\n2 ";
echo system('/bin/touch test2.txt');
echo "\n3 ";
echo exec('/bin/touch test3.txt');


/bin/touch: cannot touch `test1.txt': Permission denied
/bin/touch: cannot touch `test2.txt': Permission denied
/bin/touch: cannot touch `test3.txt': Permission denied

php script:

echo "1 ";
echo shell_exec('/bin/touch /var/www/html/beta/test1.txt');
echo "\n2 ";
echo system('/bin/touch /var/www/html/beta/test2.txt');
echo "\n3 ";
echo exec('/bin/touch /var/www/html/beta/test3.txt');


/bin/touch: cannot touch `/var/www/html/beta/test1.txt': Permission denied
/bin/touch: cannot touch `/var/www/html/beta/test2.txt': Permission denied
/bin/touch: cannot touch `/var/www/html/beta/test3.txt': Permission denied
share|improve this question
What are the permissions on ffmpeg? Have you tried specifying the absolute path to ffmopeg instead of relying on detection at runtime? does your webserver run chroot? – symcbean Oct 20 '10 at 14:05
....and what happens when you try to run it using 'su apache -c ffmpeg -i ....' – symcbean Oct 20 '10 at 14:06
Apparently I can't su into apache... I do have apache as a user though – siliconpi Oct 21 '10 at 8:16
Symcbean - are you able to su apache? – siliconpi Oct 21 '10 at 9:14
When you say "None worked", did you pass it actual arguments so as to see if it would convert? – Ignacio Vazquez-Abrams Oct 25 '10 at 7:57

A few random thoughts:

  • How long does your ffpmpeg command takes ? if it takes longer than the value of max_execution_time in php.ini, I believe that the command is canceled.

  • try to use only full paths for the ffmpeg binary and the input/output files. Although, if you have a zero size file outputted, it shouldn't be that.

  • Does apache have the permission to run the ffmpeg binary ?

  • try a basic command in your system call, such as "touch test.txt" just to check if the problem is from ffmpeg or your php script.

share|improve this answer
I dont think (1) is a problem. I've set the max_exec time to 5 mins. (2) ffmpeg is in the system path (3) I'm not sure! How do I test that? (4) you're right - this did NOT work - no file was created. – siliconpi Oct 21 '10 at 9:25
(1)is 5 minutes enough to encode your video ?. (3) what does "ps -edf|grep apache" returns ? the first column is the name of the user that runs apache, try to use it with "su <user> -c ffmpeg...". (4) this is a coding problem. can't help here. – Julien Vehent Oct 21 '10 at 10:09
ps -edf... returns: apache 19394 9134 0 10:07 ? 00:00:00 /usr/sbin/httpd apache 19395 9134 0 10:07 ? 00:00:00 /usr/sbin/httpd apache 19396 9134 0 10:07 ? 00:00:00 /usr/sbin/httpd apache 19397 9134 0 10:07 ? 00:00:00 /usr/sbin/httpd apache 19398 9134 0 10:07 ? 00:00:00 /usr/sbin/httpd apache 19399 9134 0 10:07 ? 00:00:00 /usr/sbin/httpd apache 19400 9134 0 10:07 ? 00:00:00 /usr/sbin/httpd apache 19401 9134 0 10:07 ? 00:00:00 /usr/sbin/httpd root 19960 16055 0 10:28 pts/1 00:00:00 grep apache – siliconpi Oct 21 '10 at 10:29
I can't su apache... it says: This account is currently not available. – siliconpi Oct 21 '10 at 10:29
<?php echo system("ls -al"); ?> doesnt work either – siliconpi Oct 21 '10 at 10:41

It was a permissions issue, I had selinux enabled. By changing the setting in /etc/sysconfig/selinux



The system() commands started working

share|improve this answer
Whoops! Spoke too soon... see edit2 – siliconpi Oct 22 '10 at 10:31

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