Extract Scheme and Host from HTTP_REFERER

5
votes

I have $_SERVER['HTTP_REFERER'] — pretend it is http://example.com/i/like/turtles.html. What would I need to do to get just the http://example.com part out of the string, and store it in its own variable?

4
phpstring
As a sidenote, just a remark : the Referer is not always sent by the client (it can be disabled, for instance), and it can be faked. So, don't base any critical functionnality (nor security-oriented) on it ! - Pascal MARTIN
@PascalMARTIN Sound advice. But, I think a case could be made for examining HTTP_REFERER in $_SERVER (or, using filter_input() / filter_input_array()) from an HTTP POST request. - Anthony Rutledge

4 Answers

16
votes

In this example, the best solution would be to use PHP's parse_url method. This splits up the URL into an associative array. You would then build your final value by combining the scheme with the host:

if ( $parts = parse_url( "http://example.com/i/like/turtles.html" ) ) {
    echo $parts[ "scheme" ] . "://" . $parts[ "host" ];
}
14
votes

I'd use parse_url in the following way...

if ($urlParts = parse_url($myURI))
  $baseUrl = $urlParts["scheme"] . "://" . $urlParts["host"];
3
votes

You should be able to use the parse_url function to achieve that

2
votes

You could use a regular expression:

if (isset($_SERVER['HTTP_REFERER']) && preg_match('@^[^/]+://[^/]+@', $_SERVER['HTTP_REFERER'], $match)) {
    var_dump($match[0]);
}

Or you could use the parse_url function.