php的计数器每次都会清零

<?php
$count_num=0;
if(file_exists("counter.txt"))
{
$fp=fopen("counter.txt","r");
$counter_num=fgets($fp,9);//读取前八位数字
$count_num++;
fclose($fp);

}
$fp=fopen("counter.txt","w");
fputs($fp,$count_num);
fclose($fp);

echo" hahaha $count_num hahah";
?>

这个每次显示的都是1 就算人工修改了txt也不行 php初学者 请问问题出在哪里？谢谢！！

$count_num 毫无意义
可以去掉

$counter_num=0;
if(file_exists("counter.txt"))//true exist
{
$fp=fopen("counter.txt","r");
$counter_num=fgets($fp,9);//取数
$counter_num++;           //加数
fclose($fp);

}
$fp=fopen("counter.txt","w");
fputs($fp,$counter_num);  //存数
fclose($fp);

echo" hahaha $counter_num hahah";

变量名不一样

$counter_num=fgets($fp,9); // ==》 $counter_num

其它地方都是$count_num

$count_num=0;这一句去掉即可。
另外编辑计数器count.txt文件，将初始值设为0即可。