php global function or procedure

Question

I have some php code which works to chek the incoming url and i have hundreds of php pages in which i have to chek the incoming url and i want to do make that code like a procedure or function which can be called in all php pages. So i can apply easily my code effect to all pages apparantly.Here is my php code

<?php
ob_start();
$domain = array("http://a.sml.com.pk/default.aspx","http://a.sml.com.pk/");
if(!in_array($_SERVER['HTTP_REFERER'],$domain))
{
$URL1="http://a.sml.com.pk"; 
header ("Location: $URL1");

}
else{

set_time_limit(500);
$url = 'http://appsrv01.shakarganj.com.pk:7778/reports/rwservlet?reptestsfpl&report=sales_milk';
$pdf = 'milksales.pdf';
$pdfbak = 'bak/'.$pdf;

if (filesize($pdf) > 10000)
{
copy($pdf,$pdfbak);
}

if ((int)time() > filemtime($pdf) + 30) 
{
file_put_contents($pdf, file_get_contents($url));
}
header('Pragma: public');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Content-Type: application/pdf');

if (filesize($pdf) > 10000)
{
readfile($pdf);
}
else
{
readfile($pdfbak);
}
}
?>

Now I want to make procedure for this code which should be applied in all my files

ob_start();
    $domain = array("http://a.sml.com.pk/default.aspx","http://a.sml.com.pk/");
    if(!in_array($_SERVER['HTTP_REFERER'],$domain))
    {
    $URL1="http://a.sml.com.pk"; 
    header ("Location: $URL1");

    }
    else{

Please any one help me to convert my code before else portion into procedure and how that procedure will be called in all file regrding else portion

Answer 1

function test_referer()
{
    static $domain = array("http://a.sml.com.pk/default.aspx","http://a.sml.com.pk/");
    if (!in_array($_SERVER['HTTP_REFERER'], $domain)) {
        header ("Location: http://a.sml.com.pk");
        exit;
    }
}

In your code, you would call like:

test_referer();
// domain verified, continue your code

Answer 2

you can write below code in one php file like domainCheker.php

<?php
    $domain = array("http://a.sml.com.pk/default.aspx","http://a.sml.com.pk/");
    if (!in_array($_SERVER['HTTP_REFERER'], $domain)) 
    {
        header ("Location: http://a.sml.com.pk");
        exit;
    }
?>

Now, include this php file in you all pages on starting, like

<?php
    include 'PATH_CHECK_DOMAIN';//  give the above file path 
?>

after you can start coding........!