CODEWITHSUNDEEP
phphttp-referer
Marco
Marco

Reputation: 2737

Need to know if a person comes to my website from a link inside my website, not an external website

I need to know if a person comes to my website from a link inside my website, not an external website. To be more precise, the links need to resemble something like

http://localhost/library/cat/5/fashion
http://www.mywebpage.com/library/cat/4/design

http://localhost/library/publication/7/pronto
http://www.mywebpage.com/library/publication/7/pronto

How do i find out if the HTTP_REFERER contains at least 'library/cat' or 'library/publication', and it's an internal link (comes from my live host, or localhost)?

Here's what i did so far

if ( isset($_SERVER['HTTP_REFERER') ) {

    //if the referer contains something that resembles the above url's, add icon to go back

}

Upvotes: 0

Views: 55

Answers (3)

bhamner
bhamner

Reputation: 447

The best way to accomplish this is to append a random token to your internal url and check for a match on the receiving url. There are many ways to do this, most commonly storing the value in the sesson or in a database in addition to appending it to your url, and then checking the value of the url token against your stored token on the receiving end. 

 somelink.com?token=$yourRandomToken

Upvotes: 1

sdexp
sdexp

Reputation: 776

Try this...

$subject = $_SERVER['HTTP_REFERER');
$pattern1 = '/^http:\/\/([\w.]*)\/library\/cat\//';
$pattern2 = '/^http:\/\/([\w.]*)\/library\/publication\//';

if( 1 == preg_match($pattern1, $subject, $matches) or 1 == preg_match($pattern2, $subject, $matches) ){
    // Do stuff
}

If you need to know whether it's local host or www.mywebpage.com that will be in $matches[0].

Or...

$subject = $_SERVER['HTTP_REFERER');
$pattern = '/^http:\/\/([\w.]*)\/(library\/cat|library\/publication)\//';
if( 1 == preg_match($pattern, $subject, $matches) ){
    // Do stuff
}

Where $matches[0] is the host and $matches[1] is now "library/cat" or "library/publication".

Take a look at preg_match and test the patterns out for yourself at a website like this.

Upvotes: 1

Alex Frenkel
Alex Frenkel

Reputation: 409

Actually your aproach is ok, but bear in mined that TRASTING ANY EXTERNAL DATA is not reliable and prone to hacks.

Using HTTP_REFERER, this is what I would do:

if ( !empty($_SERVER['HTTP_REFERER']) && strpos(strtolower($_SERVER['HTTP_REFERER']), '/library/cat/' ) !== false ) {

//if the referer contains something that resembles the above url's, add icon to go back

}

But if you really want to give the users a "Go Back" button, you have better solutions:

Use simple history(-1) in JS, thou this can send the user back to the search engine he came from:

function goBack() {
    window.history.go(-1);
}
<button onclick="goBack()">Go Back</button>

Your second option will be to relly on Cookies, this is a little bit more complicated but will give you the main idea 

if (empty($_SESSION['current_page'])){
    // This is our first page in this website!
    $_SESSION['current_page'] = $_SERVER['REQUEST_URI'];
} else {
    // This is our second+ page in this website, we have a back button
    $_SESSION['prev_page'] = $_SESSION['current_page'];
    $_SESSION['current_page'] = $_SERVER['REQUEST_URI'];
}

Now with this example you can play with, you can make it as an array to have more the one History event and etc.

Upvotes: 1

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