PHP面试题之文件目录操作

/*** 5种方式获取文件后缀名* 这道题其实就是考函数substr() strrchr() ?array_pop() ?strrpos() strpos() strrev() explode() ?pathinfo()* @param string $filename 要处理的文件名 ?1.jpg/1.png/1.html/1.php* @return string .php/php ?*/function get_ext1($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";

/*** 遍历目录(递归)* @param string $dir 目录名且最后没有/* @return array $files 整个目录结构*/function myScandir($dir){ ???????$files = array(); ???????if($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";print_r(myScandir($dir));