Getting PHP to run a Python script

Question

I am trying to run a Python program using PHP. Here's the code

$command = '/usr/local/bin/python script.py file';
$temp = exec($command, $output);

This works through the command line but not while running it through the browser. I am using Apache so probably it needs the right privileges? I am pretty new to Linux and have no idea how to get this working.

Any help would be appreciated!

Edit 1:

Tried to use proc_open but nothing happens. I gave the full path to the script. Made the script executable but no luck. Any other things I can try on the server? (It's a CentOS 5)

• wisty: Don't do it like this if you have any real traffic. Running a new python script (without mod-python) will cost you dearly. Set up a separate, long-running python server (xml-rpc server?), and call it using IPC if you need to scale.
• Abhinav: Thanks! Just wanted to get this done as a demo. Yet to get my way around mod_wsgi/mod_python

Answer 1

You need to pass the full path to the script and you also need to make sure that the script is readable by the user running the web server (which means every directory in the path must be +x to the web user).

• jdizzle: Just to cover all the bases, you're actually printing $output, right? You should also try and find out if your web server is running chrooted.

Answer 2

Realized what was wrong:

1. The domain was set up as a virtual host and PHP's safe_mode was enabled. proc_open, exec, system, passthru etc. do not work under safe_mode I guess.

2. Put the script in the directory accessible by the vhost. Apache wasn't able to access the directories outside the vhost document root.

Thanks for the help!

Answer 3

Few checkpoints

• script.py should be pass full path, eg, /home/abhinav/script.py
• script.py should be executable, chmod +x script.py

• LiraNuna: "script.py should be executable" not if the interpreter is invoked.
• YOU: Thanks, and #!/usr/local/bin/python would need in first line of script.py
• ZeissS: You don't need the shebang if you use the interpreter to call the script (python <filename>)
• Abhinav: I tried giving the full path to the script. Doesn't work. The browser just shows a blank page and the script execution ends. The same script runs from the command line.

Answer 4

To get my CodeIgniter helper to run a python script, I had to put #!/usr/bin/python on the first line of my python script, and NOT call python from the exec.

+1 for also doing chmod +x

My helper looks like this:

<?php
 function scrape($site, $key, $user_id)
 {
 $cmd = str_replace('system/','',BASEPATH).APPPATH."python/spider.py -u $site -k $key -i $user_id";
 $resp = exec($cmd, $out);
 return $out;
 }
?>