php man page for is_resource

IS_RESOURCE(3)								 1							    IS_RESOURCE(3)

is_resource - Finds whether a variable is a resource

SYNOPSIS
       bool is_resource (mixed	$var)

DESCRIPTION
	Finds whether the given variable is a resource.

PARAMETERS
	      o $var
		- The variable being evaluated.

RETURN VALUES
	Returns TRUE if $var is a resource, FALSE otherwise.

EXAMPLES
       Example #1

	      is_resource(3) example

	      <?php

	      $db_link = @mysql_connect('localhost', 'mysql_user', 'mysql_pass');
	      if (!is_resource($db_link)) {
		  die('Can't connect : ' . mysql_error());
	      }

	      ?>

NOTES
       Note

	      is_resource(3) is not a strict type-checking method: it will return FALSE if $var is a resource variable that has been closed.

SEE ALSO
       The resource-type documentation, get_resource_type(3).

PHP Documentation Group 													    IS_RESOURCE(3)