The simplest PHP program--Counter_PHP Tutorial

Principle:
1. The first user browses a certain page.
2. The server program reads the number of times the page has been viewed from the database or file.
3. Store the number of times plus one and send it back to the first user.
4. The second user browses a certain page.
5. The server program reads the number of times the page has been viewed from the database or file.
6. Save the number by one and send it back to the second user.
Functions you need to know:
fopen() opens a file
filesize() gets the file size
fseek() moves the file pointer
fgets() gets the line content of the file pointer
fputs () Write the string as the location of the file pointer
fclose() Close the file
file_exists() Determine whether the file exists
exec() Execute an external program

The simplest counter :

< ?php
/*
(c)1998 David W. Bettis
Here is the copyright information
*/

$counterFile = "counter.txt";
#here Define the counter file

function displayCounter($counterFile) {
$fp = fopen($counterFile,"rw");
#Open the file in read and write mode

$num = fgets($fp,5);
#Get the current number

$num += 1;
#Add 1

print "You are the number" ."$num"." A boring person";
exec( "rm -rf $counterFile");
exec( "echo $num > $counterFile");
#Lazy way. , do not use fputs to write
}

if (!file_exists($counterFile)) {
exec( "echo 0 > $counterFile");
}#if counter The file does not exist, create it and set the content to 0

displayCounter($counterFile);

?>
>PHP counter simpler version:
#No copyright, so simple

$fp=fopen("counter.txt","r+");
flock($fp,3);
#Open the counter file and lock it

$fsize=filesize("count.txt");
$count=fgets($fp,$ fsize+1);
$count++;
#Get the number and add one

fseek($fp,0);
fputs($fp,$count);
fclose ($fp);
#Write new number to file

echo "You are the $count visitor";
?>

PHP counter graphic Version:
Create 10 pictures and combine the number strings with pictures. I won’t go into details.
Assume the pictures are 0.gif ~ 9.gif

. ...$count is the obtained value
$strcount=strval($count);
$strcount=chop($strcount);
$countlen=$strlen($strcount);
$ shtml="";
for ($i=0; $i<$countlen; $i++) {
$shtml.="";
}
echo $shtml;
?>

PHP counter database version:
Use SQL counter, create the table first
CREATE TABLE counter
(
counter int not null,
id int not null
)
INSERT INTO counter(counter,id) VALUE(0,1)

$conn=mysql_connect(..., ..., ...);
#MySQL database Connection

$sql="select * from counter";
$result=mysql_query($sql,$conn);
$objresult=mysql_fetch_object($result);
$count= $objresult->counter;
$count++;

$sql="update counter set counter=".$count."where id=1";
mysql_query($sql,$conn );
mysql_close($conn);


echo "You are the $count visitor";
?>

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