PHP 文件扩展名 获取函数

<?php 
$file = "/home/lvyaozu/backup_20080115.txt"; for($i=1; $i < 6; $i++) { 
$func = 'get_file_ext_' . $i; 
var_dump($func($file)); 
} 

function get_file_ext_1($file) { 
return strtolower(trim(substr(strrchr($file, '.'), 1))); 
} 
function get_file_ext_2($file) { 
return strtolower(trim(pathinfo($file, PATHINFO_EXTENSION))); 
} 
function get_file_ext_3($file) { 
return strtolower(trim(substr($file, strrpos($file, '.')+1))); 
} 
function get_file_ext_4($file) { 
return strtolower(trim(array_pop(explode('.', $file)))); 
} 
function get_file_ext_5($file) { 
$tok = strtok($file, '.'); 
while($tok !== false) { 
$return = $tok; 
$tok = strtok('.'); 
} 
return strtolower(trim($return)); 
} 
?> 
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/lvyaozu/archive/2009/06/03/4237628.aspx