复制代码 代码如下:
<?php
/**
* 仿qq验证码
*/
//session保存路径
$sesssavepath = dirname(__file__)."/../data/sessions/";
if(is_writeable($sesssavepath) && is_readable($sesssavepath)){ session_save_path($sesssavepath); }
session_start();
//获取随机字符
$rndstring = '';
for($i=0; $i<4; $i++) $rndstring .= chr(mt_rand(65,90));
$img_height=45; //先定义图片的长、宽
$img_width=10;
//如果支持gd,则绘图
if(function_exists("imagecreate"))
{
//firefox部份情况会多次请求的问题,5秒内刷新页面将不改变session
$ntime = time();
if(empty($_session['dd_ckstr_last']) || empty($_session['dd_ckstr']) || ($ntime - $_session['dd_ckstr_last'] > 5))
{
$_session['dd_ckstr'] = strtolower($rndstring);
$_session['dd_ckstr_last'] = $ntime;
}
$rndstring = $_session['dd_ckstr'];
$rndcodelen = strlen($rndstring);
//创建图片,并设置背景色
$im = imagecreate(46,20);
imagecolorallocate($im, 240,243,248);
//干扰线
$linecolor1 = imagecolorallocate($im, mt_rand(174,218),mt_rand(190,225),mt_rand(217,237));
for($j=1;$j<=2;$j=$j+3)
{
imageline($im,0,$j+mt_rand(1,15),48,$j+mt_rand(1,15),$linecolor1);
}
//输出文字
$fontcolor = imagecolorallocate($im, mt_rand(0,150),mt_rand(0,150),mt_rand(0,150));
for($i=0;$i<$rndcodelen;$i++)
{
$bc = mt_rand(0,1);
$rndstring[$i] = strtoupper($rndstring[$i]);
imagestring($im,mt_rand(3,5),$i*$img_height/4+mt_rand(1,5),mt_rand(1,$img_width/2), $rndstring[$i], $fontcolor);
}
header("pragma:no-cache"r"n");
header("cache-control:no-cache"r"n");
header("expires:0"r"n");
//输出特定类型的图片格式,优先级为 gif -> jpg ->png
if(function_exists("imagepng"))
{
header("content-type:image/png"r"n");
imagepng($im);
}
else
{
header("content-type:image/jpeg"r"n");
imagejpeg($im);
}
imagedestroy($im);
exit();
}
else
{
//不支持gd,只输出字母 abcd
$_session['dd_ckstr'] = "abcd";
$_session['dd_ckstr_last'] = '';
header("content-type:image/png"r"n");
header("pragma:no-cache"r"n");
header("cache-control:no-cache"r"n");
header("expires:0"r"n");
$fp = fopen("data/vdcode.jpg","r");
echo fread($fp,filesize("data/vdcode.jpg"));
fclose($fp);
exit();
}
?>
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