简单PHP图像计数器实现

Posted 2021-05-16 royal_coffee

转自ChinaLab php教程中的程序!

 

图像计数器

所需文件:

exa3-5.php // 主调用文件
exa3-5.inc // 计数函数
exa3-5.dat // 数据记录文件
img/  // 记数图像文件夹，内有文件0.gif ~ 9.gif 

 

详细代码如下:

exa3-5.php

<? php
     require ( " exa3-5.inc " );
?>
< html >
     < head >< title > 我的计数器 </ title ></ head >
     < body >
         < p > 欢迎进入我的网站 </ p >
        您是本站第 <? php counter();  ?> 位访客 !< br >
     </ body >
</ html >

 

exa3-5.inc 

 

<? php
     function  counter(){
         $max_len   =   8 ;
         $CounterFile   =   " exa3-5.dat " ;

         if ( ! file_exists ( $CounterFile )){
             $Counter   =   0 ;
             $cf   =   fopen ( $CounterFile ,   " w " );
             flock ( $cf ,   3 );
             fputs ( $cf ,   " 0 " );
             fclose ( $cf );
        }
         else {
             $cf   =   fopen ( $CounterFile ,   " r " );
             flock ( $cf ,   3 );
             $Counter   =   trim ( fgets ( $cf ,   $max_len ));
             fclose ( $cf );
        }

         if ( session_is_registered ( " in " )  ==   false ){
             $Counter ++ ;
             $cf   =   fopen ( $CounterFile ,   " w " );
             flock ( $cf ,   3 );
             //  1 、表示设定锁住档案可以允许别的行程读取；
            // 2 、表示只有该行程可以写入档案；
            // 3 、表示读写均锁住；
            // 4 、不锁住区块 (block)。
             fputs ( $cf ,   $Counter );
        }

         $Counter_len   =   strlen ( $Counter );

         for ( $i = 1 ;  $i <= ( $max_len - $Counter_len );  $i ++ ){
             echo   " <img src='img/0.gif'> " ;
        }

         for ( $i = 1 ;  $i <= $Counter_len ;  $i ++ ){
             echo   " <img src='img/ "   .   substr ( $Counter ,   $i - 1 ,   1 )  .   " .gif'> " ;
        }
    }
?>