php 判断图片文件的真实类型

不多说，代码奉上

<?php
/**
 * 检测文件的真实类型
 * @param  string srcPath 文件路径
 * @return stringrealType 文件真实类型
*/

imgurl = '图片链接';
echo file_type_detect(imgurl);
function file_type_detect(srcPath){types = array(
        6677    => 'bmp',
        7173    => 'gif',
        7368    => 'mp3',
        13780   => 'png',
        255216  => 'jpg',
    );  

    binary = curl_get(srcPath);
    bytes = substr(binary, 0, 2); 
    head = @unpack('C2char',bytes);
    typeCode = intval(head['char1'].head['char2']);realType = isset(types[typeCode]) ? types[typeCode] : typeCode;
    returnrealType;
}
function curl_get(url){ch=curl_init(url);
    curl_setopt(ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt(ch, CURLOPT_SSL_VERIFYHOST, false);
    curl_setopt(ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt(ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Linux; U; Android 4.4.1; zh-cn; R815T Build/JOP40D) AppleWebKit/533.1 (KHTML, like Gecko)Version/4.0 MQQBrowser/4.5 Mobile Safari/533.1');
    curl_setopt(ch, CURLOPT_TIMEOUT, 10);
    content=curl_exec(ch);
    curl_close(ch);
    return(content);
}