PHP traverses all file functions in a specified directory and can specify the file type

This is better than scandir is easy to use

 /**
 * Traverse to obtain files of the specified type in the directory
 * @param $path
 * @param array $files
 * @return array
*/
 function getfiles( $path , &$files = array() )
 {
 if ( !is_dir( $path ) ) return null;
 $handle = opendir( $path );
 while ( false !== ( $file = readdir( $handle ) ) ) {
 if ( $file != '.' && $file != '..' ) {
 $path2 = $path . ' /' . $file;
 if ( is_dir( $path2 ) ) {
 getfiles( $path2 , $files );
 } else {
 if ( preg_match( "/.(gif|jpeg|jpg|png|bmp)$ /i" , $file ) ) {
 $files[] = $path2;
 }
 }
 }
 }
 return $files;
 }