Question

Is there a way to perform double require_once statement where the second one as a fallback if the first one fails?

For example: I can do this

mysql_query() or die("Boo");

Could I do:

require_once('filename') or require_once('../filename');

If one fails it reverts to the other?

Answer 1

You can’t do this because of a weird little quirk in PHP. require_once() is a language construct, not a function. It will interpret the whole line as the argument:

(('filename') or require_once('../filename'))

(added braces for clarity) the result of this operation is 1.

Use is_readable() instead.

if (is_readable($filename)) 
  require_once($filename); 
    else require_once("../$filename");

or a shorter version that should work:

require_once(is_readable($filename) ? $filename : "../$filename");