php获取图片真实后缀的两种方法

一、getimagesize（支持base64）：

1. 代码：

   <?php
   /*
   @desc：获取图片真实后缀
   @param   name    文件名
   @return  suffix  文件后缀
   */   
   function getimgsuffix($name) {
   $info = getimagesize($name);
   $suffix = false;
   if($mime = $info['mime']){
       $suffix = explode('/',$mime)[1];
   }
   return $suffix;
   }

2. 测试：

   $suffix = getimgsuffix('http://192.168.8.81/public/image/01.jpg');
   echo $suffix;

3. 输出：

   jpeg

   二、二进制方法：

4. 代码：

   <?php
   /*
   @desc：获取文件真实后缀
   @param   name    文件名
   @return  suffix  文件后缀
   */   
   function getfilesuffix($name) {
   $file = fopen($name, "rb");
   $bin = fread($file, 2); // 只读2字节
   fclose($file);
   $info = @unpack("C2chars", $bin);
   $code = intval($info['chars1'] . $info['chars2']);
   $suffix = "unknow";
   if($code == 255216){
       $suffix = "jpg";
   }elseif($code == 7173){
       $suffix = "gif";
   }elseif($code == 13780){
       $suffix = "png";
   }elseif($code == 6677){
       $suffix = "bmp";
   }elseif($code == 7798){
       $suffix = "exe";
   }elseif($code == 7784){
       $suffix = "midi";
   }elseif($code == 8297){
       $suffix = "rar";
   }elseif($code == 7368){
       $suffix = "mp3";
   }elseif($code == 0){
       $suffix = "mp4";
   }elseif($code == 8273){
       $suffix = "wav";
   }
   return $suffix;
   }

5. 测试：

   $suffix = getfilesuffix('http://192.168.8.81/public/image/01.jpg');
   echo $suffix;

6. 输出：

   jpg