php man page for file_exists

FILE_EXISTS(3)								 1							    FILE_EXISTS(3)

file_exists - Checks whether a file or directory exists

SYNOPSIS
       bool file_exists (string  $filename)

DESCRIPTION
	Checks whether a file or directory exists.

PARAMETERS
	      o $filename
		- Path to the file or directory.  On windows, use //computername/share/filename or \computernamesharefilename to check files on
		network shares.

RETURN VALUES
	Returns TRUE if the file or directory specified by $filename exists; FALSE otherwise.

       Note

	       This function will return FALSE for symlinks pointing to non-existing files.

       Warning

	       This function returns FALSE for files inaccessible due to safe mode restrictions. However these files still can be included if they
	      are located in safe_mode_include_dir.

       Note

	       The check is done using the real UID/GID instead of the effective one.

       Note

	       Because PHP's integer type is signed and many platforms use 32bit integers, some filesystem functions may return unexpected results
	      for files which are larger than 2GB.

EXAMPLES
       Example #1

	      Testing whether a file exists

	      <?php
	      $filename = '/path/to/foo.txt';

	      if (file_exists($filename)) {
		  echo "The file $filename exists";
	      } else {
		  echo "The file $filename does not exist";
	      }
	      ?>

ERRORS
/EXCEPTIONS
	Upon failure, an E_WARNING is emitted.

NOTES
       Note

	      The results of this function are cached. See clearstatcache(3) for more details.

       Tip

	      As of PHP 5.0.0, this function can also be used with some URL wrappers. Refer to "Supported Protocols  and  Wrappers"  to  determine
	      which wrappers support stat(3) family of functionality.

SEE ALSO
       is_readable(3), is_writable(3), is_file(3), file(3).

PHP Documentation Group 													    FILE_EXISTS(3)