Tells whether the given file is a symbolic link.
Path to the file.
Returns true if the filename exists and is a symbolic link, false otherwise.
Exceptions and Errors
Upon failure, an E_WARNING is emitted.
The results of this function are cached. See clearstatcache for more details.
As of PHP 5.0.0, this function can also be used with some URL wrappers. Refer to to determine which wrappers support stat family of functionality.