PHP exec()

[raymondhui]

Hello all,

I am just a PHP beginner. And i've got a prolem of exec() function with PHP..

As i know, PHP is a SSL of Apache, therefore, the user of PHP is as Apache, that make me facing a problem about rights in Linux system.

If there is a executable file that should be either run as root or a specified user but not as apache, How can i run such executable file in PHP script??

Can i change myself as another user and run it?

Regards,
Raymond Hui

[Anon]

No, you can't change the user who is PHP. The only way to do this is to build an SUID (Set User ID) script and make that script run what you want run. I'm not going to explain how to set up an SUID script because they are dangerous. There are many places on the web that will tell you how to do it.

But let me warn you, that if you build an SUID script then you are giving anyone who uses your website the ability to run a program as if they were ROOT. This is an extreem security risk. I can't state that strongly enough. You can make SUID scripts that are secure, but you need to make sure you understand fully what you are doing before you do it. Many security exploits come from SUID scripts.

You have been warned.