http://www.jb51.net/article/28167.htm
<?php
$content="老黄";
if(file_exists("PHP.txt"))
{
$fp=fopen("PHP.txt",‘ab‘);
while(!feof($fp))
{
echo fgets($fp,4096);
}
fclose($fp);
}
获取文件大小
$filename="PHP.txt";
echo $filename.‘:‘.filesize($filename).‘bytes‘;
?>
原文：http://www.cnblogs.com/csharphuang/p/4241389.html