php 网站计数器

一 简单数字计数器（session无刷新计数器）

if(($fp=fopen("counter.txt","r+"))==false)
{
    echo "打开文件失败！";
}
else
{
    $counter = fgets($fp,1024);
    if(empty($_SESSION['temp']))
    {
        $counter++;
        if(($fp=fopen("counter.txt","w"))==false)
            echo "打开文件失败！";
        else
            fputs($fp,$counter);
        $_SESSION['temp']=1;
    }
    fclose($fp);
    echo "网站当前访问量：".$counter;
}