PHP Functions Essential Reference

is_resource

bool is_resource(mixed value) 

Tests whether a value is a resource pointer.

Returns:

TRUE if the value is a resource pointer; FALSE otherwise

Description:

is_resource() checks whether value is a resource pointer that has been returned by a call to fopen(), popen(), opendir(), etc., or one of the database functions such as mysql_connect(), msql_pconnect(), etc. If so, the function returns TRUE. If not, FALSE is returned.

Availability:

UNIX, Windows

Version:

3+, 4+

See also:

gettype() 

Example:

Test whether a value is a resource pointer

$dir_handle = opendir ('..'); if (is_resource ($dir_handle)) print '$dir_handle is a resource pointer.'; else print '$dir_handle is not a resource pointer.';