Deletes filename. Similar to the Unix C unlink() function. �\�^��TRUE�Ѧ^��FALSE�C
注: As of PHP 5.0.0 unlink() can also be used with some URL wrappers. Refer to 附錄 M for a listing of which wrappers support unlink().
注: Context support was added with PHP 5.0.0. For a description of contexts, refer to 參考 CLIII, Stream Functions.
See also rmdir() for removing directories.