php man page for feof

FEOF(3) 								 1								   FEOF(3)

feof - Tests for end-of-file on a file pointer

SYNOPSIS
       bool feof (resource  $handle)

DESCRIPTION
	Tests for end-of-file on a file pointer.

PARAMETERS
	      o $handle
		-The  file  pointer must be valid, and must point to a file successfully opened by fopen(3) or fsockopen(3) (and not yet closed by
		fclose(3)).

RETURN VALUES
	Returns TRUE if the file pointer is at EOF or an error occurs (including socket timeout); otherwise returns FALSE.

NOTES
       Warning

	       If a connection opened by fsockopen(3) wasn't closed by the server, feof(3) will hang. To workaround this, see below example:

	      Example #1

		     Handling timeouts with feof(3)

		     <?php
		     function safe_feof($fp, &$start = NULL) {
		      $start = microtime(true);

		      return feof($fp);
		     }

		     /* Assuming $fp is previously opened by fsockopen() */

		     $start = NULL;
		     $timeout = ini_get('default_socket_timeout');

		     while(!safe_feof($fp, $start) && (microtime(true) - $start) < $timeout)
		     {
		      /* Handle */
		     }
		     ?>

       Warning

	       If the passed file pointer is not valid you may get an infinite loop, because feof(3) fails to return TRUE.

	      Example #2

		     feof(3) example with an invalid file pointer

		     <?php
		     // if file can not be read or doesn't exist fopen function returns FALSE
		     $file = @fopen("no_such_file", "r");

		     // FALSE from fopen will issue warning and result in infinite loop here
		     while (!feof($file)) {
		     }

		     fclose($file);
		     ?>

PHP Documentation Group 														   FEOF(3)