How do I give PHP write access to a directory?

Question

I'm trying to use PHP to create a file, but it isn't working. I am assuming this is because it doesn't have write access (it's always been the problem before). I tried to test if this was the problem by making the folder chmod 0777, but that just ended up making every script in that directory return a 500 error message until I changed it back. How do I give PHP write access to my file system so it can a create a file?

Edit: It is hosted on Hostgator shared hosting using Apache.

Edit 2: Someone asked for the code: The code is a GD image script. I know the rest of it works as previously I was creating the image every ime it was called. Now I am trying to create them when new text is added and save them to a folder. The write line I have is: imagejpeg(null,$file,85);

I also created a test file to check if it was just a broken script (mainly copied from tizag): http://gearboxshow.info/rkr/lesig.jpg/testfile.txt (I don't know if/how to post the code here properly. Here is the contents of the PHP script, minus PHP tags.)

It returns 13,13,1 (separate lines), so it looks as if it thinks it wrote something, but the testfile.txt is blank (I uploaded a blank one), or non-existent (if I delete it).

Edit 3: The server runs CentOS.

Answer 1

Here is a very good tutorial that might give you an idea what permission to use.

Answer 2

An very easy way is to let PHP create the directory itself in the first place.

<?php
 $dir = 'myDir';

 // create new directory with 777 permissions if it does not exist yet
 // owner will be the user/group the PHP script is run under
 if ( !file_exists($dir) ) {
  mkdir ($dir, 0777);
 }

 file_put_contents ($dir.'/test.txt', 'Hello File');

This saves you the hassle with permissions.

Answer 3

You can change the permissions of a folder with PHP's chmod(). More information on how to use the command is here: http://php.net/manual/en/function.chmod.php

If you get a 500 Error when setting the permissions to 777 (world writable), then it means your server is setup to prevent executing such files. This is done for security reasons. In that case, you will want to use 755 as the highest permissions on a file.

If there is an error_log file that is generated in the folder where you are executing the PHP document, you will want to view the last few entries. This will give you an idea where the script is failing.

For help with PHP file manipulation, I use http://www.tizag.com/phpT/filewrite.php as a resource.

Answer 4

Set the owner of the directory to the user running apache. Often nobody on linux

chown nobody:nobody <dirname>

This way your folder will not be world writable, but still writable for apache :)

Answer 5

OK, I just set up a new server and all my folders set to 0777 give the 500 server error. I have never had this problem before. I see it is a security feature but how do I remove it?

Answer 6

I'm dealing with this same issue. http://superuser.com/questions/179693/drupal-install-and-permissions

I've tried

chmod -R apache:apache *

I used the following script to get the current user name. Though still no luck.

<?php
passthru("whoami");
?>