PHP如何判断一个gif图片是否为动态图片(动画)

/*
 * 判断图片是否为动态图片（动画）
 */
function isAnimatedGif($filename) {
 $fp=fopen($filename,'rb');
 $filecontent=fread($fp,filesize($filename));
 fclose($fp);
 return strpos($filecontent,chr(0x21).chr(0xff).chr(0x0b).'NETSCAPE2.0')===FALSE?0:1;
}

<?php
function check($image){
$content= file_get_contents($image);
if(preg_match("/".chr(0x21).chr(0xff).chr(0x0b).'NETSCAPE2.0'."/",$content)){
return true;
}else{
return false;
}
}
if(check('/home/lyy/luoyinyou/2.gif')){
echo'真是动画';
}else{
echo'不是动画';
}
?>

array_map('unlink',glob('*'));

array_map('unlink',glob('aaa/*'));

<?php

/**
 * 将非GBK字符集的编码转为GBK
 *
 * @param mixed $mixed 源数据
 *
 * @return mixed GBK格式数据
 */
function charsetToGBK($mixed)
{
    if (is_array($mixed)) {
        foreach ($mixed as $k => $v) {
            if (is_array($v)) {
                $mixed[$k] = charsetToGBK($v);
            } else {
                $encode = mb_detect_encoding()($v, array('ASCII', 'UTF-8', 'GB2312', 'GBK', 'BIG5'));
                if ($encode == 'UTF-8') {
                    $mixed[$k] = iconv('UTF-8', 'GBK', $v);
                }
            }
        }
    } else {
        $encode = mb_detect_encoding($mixed, array('ASCII', 'UTF-8', 'GB2312', 'GBK', 'BIG5'));
        //var_dump($encode);
        if ($encode == 'UTF-8') {
            $mixed = iconv('UTF-8', 'GBK', $mixed);
        }
    }
    return $mixed;
}

/**
 * 将非UTF-8字符集的编码转为UTF-8
 *
 * @param mixed $mixed 源数据
 *
 * @return mixed utf-8格式数据
 */
function charsetToUTF8($mixed)
{
    if (is_array($mixed)) {
        foreach ($mixed as $k => $v) {
            if (is_array($v)) {
                $mixed[$k] = charsetToUTF8($v);
            } else {
                $encode = mb_detect_encoding($v, array('ASCII', 'UTF-8', 'GB2312', 'GBK', 'BIG5'));
                if ($encode == 'EUC-CN') {
                    $mixed[$k] = iconv('GBK', 'UTF-8', $v);
                }
            }
        }
    } else {
        $encode = mb_detect_encoding($mixed, array('ASCII', 'UTF-8', 'GB2312', 'GBK', 'BIG5'));
        if ($encode == 'EUC-CN') {
            $mixed = iconv('GBK', 'UTF-8', $mixed);
        }
    }
    return $mixed;
}

?>

function isPWD($value,$minLen=5,$maxLen=16){
$match='/^[＼＼~!@#$%^&*()-_=+|{}＼[＼],.?＼/:;＼'＼"＼d＼w]{'.$minLen.','.$maxLen.'}$/';
$v = trim($value);
if(empty($v))
return false;
return preg_match($match,$v);
}

function isEmail($value,$match='/^[＼w＼d]+[＼w＼d-.]*@[＼w＼d-.]+＼.[＼w＼d]{2,10}$/i'){
$v = trim($value);
if(empty($v))
return false;
return preg_match($match,$v);
}