这个如何实现？？？急 (在线等待)

Question

<?php
session_start();
session_register("count");
$count++;
$count="0000".$count;
$todayvar=date("Ymd");
echo $todayvar.substr($count,-4);
?>

Answer 1

<?php
session_start();
if(session_is_registered("count"))
{
  $count++;
}
else
{
  session_register("count");
  $count=1;
}
$count="0000".$count;
$todayvar=date("Ymd");
echo $todayvar.substr($count,-4);
?>

Answer 2

$todayvar=date("Ymd");
if(!file_exists("counter.txt"))
{
$fp=fopen("counter.txt","w");
fputs($fp,$todayvar."0001");
fclose($fp);
echo $todayvar."0001";
}
else{
$fp=fopen("counter.txt","r");
$data=fgets($fp,4096);
fclose($fp);
$count=substr(trim($data),-4);
$count1=intval($count)+1;
$tmp="0000".$count1;
$tmp=substr($tmp,-4);
$data=$todayvar.$tmp;
$fp=fopen("counter.txt","w");
flock($fp);
fputs($fp,$data);
fclose($fp);
echo $data;
}

Answer 3

这是在我机器上通过的代码<?php
$fname="count.dat";
$date=date('Ymd');
if (file_exists($fname)){
$comment=file($fname);
$comment=$comment[0];
$comment_ok=$date.substr(++$comment,-4);
$fp=fopen($fname,w);
fwrite($fp,$comment_ok);
}else{
$fp=fopen($fname,w);
fwrite($fp,$date.'0001');
$comment_ok=$date.'0001';
}
fclose($fp);
echo $comment_ok;
?>

Answer 4

还有问题：<?php
$fname="count.dat";
$date=date('Ymd');
if (file_exists($fname)){
$comment=file($fname);
$comment=$comment[0];
$comment_ok=$date.substr(++$comment,-4);
$fp=fopen($fname,w);
fwrite($fp,$comment_ok);
}else{
$fp=fopen($fname,w);
fwrite($fp,$date.'0001');
$comment_ok=$date.'0001';
}
fclose($fp);
echo $comment_ok;
?>上边这段代码不能根据日期的变化而刷新'0001'的变数!!!问题：
下边的示例如何实现？？？
2002-09-20
计数器显示：200209200001，200209200002，200209200003，
2002-09-21
计数器显示：200209210001，200209210002，200209210003，
2002-09-22
计数器显示：200209220001，200209220002，200209220003