The file directory operation of PHP surface question

Get file suffix, traverse directory hierarchy

/*** 5 ways to get the file suffix name * This problem is actually the test function substr () STRRCHR ()  Array_pop () Strrpos () Strpos () Strrev ()  explode ()  PathInfo () * @param string $filename The file name 1.jpg/1.png/1.html/1.php* to process  @return string. php/php  */function get_ Ext1 ($filename) {        return strrchr ($filename, '. ');} function Get_ext2 ($filename) {        return substr ($filename, Strrpos ($filename, '. '));} function Get_ext3 ($filename) {        return Array_pop (Explode ('. ', $filename));} function Get_ext4 ($filename) {        return pathinfo ($filename, pathinfo_extension);} function Get_ext5 ($filename) {        return Strrev (substr (Strrev ($filename), 0,strpos (Strrev ($filename), '. ')));} $filename = "1.php"; Echo get_ext1 ($filename). " \ n "; Echo get_ext2 ($filename)." \ n "; Echo get_ext3 ($filename)." \ n "; Echo Get_ext4 ($filename)." \ n "; Echo get_ext5 ($filename)." \ n ";

　　

/*** Traversal Directory (Recursive) * @param string $dir directory name and finally no/* @return array $files Entire directory structure */function myscandir ($dir) {        $files = array (); C1/>if ($handle = Opendir ($dir)) {while                (($file = Readdir ($handle)) = False) {                        if ($file! = "." && $file! = "..") {                                $newDir = $dir. " /". $file;                                if (Is_dir ($newDir)) {                                        $files [$file] = Myscandir ($newDir);                                } else{                                        $files [] = $file;}}                }                Closedir ($handle);                return $files;        }} $dir = "/dirname";p Rint_r (Myscandir ($dir));

　　

The file directory operation of PHP surface question