五种方式获取文件扩展名-转载未验证「原」

Five ways to get file extensions - reproduced without verification

Posted by LingDie | 靈蝶 on May 28, 2014

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<?php
 
 $file = siyuantlw/程序设计.php;
 
 function getExt1($file) {
  return substr(strrchr($file,.'),1);
 }
 function getExt2($file) {
  return substr($file,strrpos($file,’.')+1);
 }
 function getExt3($file) {
  return strrev(substr(strrev($file),0,strpos(strrev($file),.')));
 }
 function getExt4($file) {
  return array_pop(explode(‘.’,$file)); #array_pop 介绍
 }
 function getExt5($file) {
  $arr = pathinfo($file);
  return $arr['extension'];
  #或者写成下面这种
  #return pathinfo($file,PATHINFO_EXTENSION);
 }
 function getExt6($file) {
  $temp = strtok($file, .); #strtok函数说明
     while($temp !== false ){
         $file_extension = $temp;
         $temp = strtok(.);
     }
     return $file_extension;
 }

function getExt7($file) {
  while($dot = strpos($file, .))
  {
   $file = substr($file, $dot+1);
  }
  return $file;
 }
 echo getExt1($file).<br />’;
 echo getExt2($file).’<br />;
 echo getExt3($file).<br />’;
 echo getExt4($file).’<br />;
 echo getExt5($file).<br />’;
 echo getExt6($file).’<br />;

echo getExt7($file).<br />’;