PHP fopen() not creating file if it doesn't already exist

Question

As part of application logging, I'm attempting to open a local file, and if that file doesn't already exist, to create the new one. Here's what I have:

$path = '/home/www/phpapp/logs/myawesome_logfile.txt'; $f = (file_exists($path))? fopen($path, "a+") : fopen($path, "w+"); fwrite($f, $msg); fclose($f); chmod($path, 0777); 

I've double-checked, and the /logs directory is chmod 0777, and I even went the extra step of chown'ing it to apache:apache for good measure. Still, when the script goes to open the file, it gives me the warning that the file doesn't exist and bombs out. No file is ever created.

Do I need to suppress the fopen() warning to get it to create the file?

Answer 1

When you're working with paths in PHP, the context can matter a great deal. If you're working with urls in a redirection context -- then the root directory ('/') refers to your domain's root. The same goes for paths for linking files or images and for include and require directives.

However, when you're dealing with file system commands such as fopen, the root directory ('/') is the system root. Not your domain root.

To fix this, try giving the full path to the log file you want to open from the system root. For example: /var/www/phpapplication/logs/myLogFile.txt

Or you could use $_SERVER['DOCUMENT_ROOT'] as suggested in other answers to access your server's stored value for the path to the document root. The /var/www part.

You can also use the __DIR__ magic constant in some cases. Note that __DIR__ will be the directory the current file is in, which is not necessarily the same as your application's root. So for example, if your application's root is /var/www/application and you're working in /var/www/application/src/controllers/my_controller.php, then __DIR__ will be /var/www/application/src/controllers. See here in the PHP documentation.