Visitor counter is an easy way to track number of visitors coming to a web site, while sophisticated trackers can give detailed statistics of visitors, a simple visitor counter like the one we’re going tot create, would only track the number of times a web page (or site) has been requested.
A simple visitor counter which only tracks number of pageloads is very easy to create. It is obvious that the number of pageloads has to be preserved across different runs so we need to store that data in a Database or file. To ease things we’ll use a file.
Every time the page (with the script) is requested the value (number of pageloads) will be read from and incremented in the file. The initial value in the file should be 0.
Here is the code:
<?php
//function
function showCounter()
{
//open the file in read & write mode
$fp=fopen("counter.txt","r+");
//fetch pageload data
$pageloads=(int)fgets($fp,20);
//increment it
$pageloads++;
//seek to the start of file
fseek($fp,0);
//write the new value
fputs($fp,$pageloads);
//printf function is used to pad the
//pageload value, to make it look
//good
return (printf("<h1><span style=\"color: #fff;
background: #000;\">%010d
</span></h1>",$pageloads));
}
?>
Save this file with the name ‘counter.php’.
For this script to run you first need to create a file named ‘counter.txt’ with the value ‘0’ in the same directory the script is in.
Everything in the code above looks familiar except these lines:
function showCounter()
{
Well, this is how we create functions in PHP. Unlike C/C++ we don’t need to mention the return type of the function but the function-name should be preceded with the keyword ‘function’. You may return value of any data type from the function.
We have employed this method as to make it easier to integrate the visitor counting script to existing web pages. If suppose we have an existing web page named index.php, we can easily integrate this script as follows:
<?php include 'counter.php'; ?>
<html>
<head><title>Counter Example</head>
</head>
<body>
<h1>My Web Site</h1>
<?php showCounter(); ?>
</body>
</html>
Simple! We’re just including the script at the top to make the function available and at the bottom we’re calling the showCounter() functions to show visitor counter.
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