Convert URI to URL - php

Question

How to convert an URI to URL if I know the current site path?
Consider these examples:
Current path is: `http://www.site.com/aa/folder/page1.php
Uri: folder2/page.php
Uri: /folder2/page.php
And what if the current path is:
`http://www.site.com/aa/folder/
or
`http://www.site.com/aa/folder
What the URLs will look like then?
I know this should be easy and obvious, but I can't find anywhere the complete answer (and yes, I did searched on Google)

Answer 1

Here is a block of code that has the function that you need:
http://ca.php.net/manual/en/function.parse-url.php#76682
Edit: The above linked function modified with an example
<?php
var_dump(resolve_url('http://www.site.com/aa/folder/page1.php','folder2/page.php?x=y&z=a'));
var_dump(resolve_url('http://www.site.com/aa/folder/page1.php','/folder2/page2.php'));
function unparse_url($components) {
return $components['scheme'].'://'.$components['host'].$components['path'];
}
/**
* Resolve a URL relative to a base path. This happens to work with POSIX
* filenames as well. This is based on RFC 2396 section 5.2.
*/
function resolve_url($base, $url) {
if (!strlen($base)) return $url;
// Step 2
if (!strlen($url)) return $base;
// Step 3
if (preg_match('!^[a-z]+:!i', $url)) return $url;
$base = parse_url($base);
if ($url{0} == "#") {
// Step 2 (fragment)
$base['fragment'] = substr($url, 1);
return unparse_url($base);
}
unset($base['fragment']);
unset($base['query']);
if (substr($url, 0, 2) == "//") {
// Step 4
return unparse_url(array(
'scheme'=>$base['scheme'],
'path'=>$url,
));
} else if ($url{0} == "/") {
// Step 5
$base['path'] = $url;
} else {
// Step 6
$path = explode('/', $base['path']);
$url_path = explode('/', $url);
// Step 6a: drop file from base
array_pop($path);
// Step 6b, 6c, 6e: append url while removing "." and ".." from
// the directory portion
$end = array_pop($url_path);
foreach ($url_path as $segment) {
if ($segment == '.') {
// skip
} else if ($segment == '..' && $path && $path[sizeof($path)-1] != '..') {
array_pop($path);
} else {
$path[] = $segment;
}
}
// Step 6d, 6f: remove "." and ".." from file portion
if ($end == '.') {
$path[] = '';
} else if ($end == '..' && $path && $path[sizeof($path)-1] != '..') {
$path[sizeof($path)-1] = '';
} else {
$path[] = $end;
}
// Step 6h
$base['path'] = join('/', $path);
}
// Step 7
return unparse_url($base);
}
?>

Answer 2

The $_SERVER superglobal will have the information you're looking for, namely $_SERVER['REQUEST_URI'] and $_SERVER['SERVER_NAME']. $_SERVER['QUERY_STRING'] might also be useful.
Please see:
http://php.net/manual/en/reserved.variables.server.php

Answer 3

php has pathinfo(), realpath() and parseurl() and other filesystem and url path functions. Used together with info from the $_SERVER superglobal (as mentioned by andre), you should be able to do what you need.

Answer 4

$uri = "http://www.site.com/aa/folder/";
$url = explode("/", $uri);
$url = $url[2];
echo $url; //www.site.com
Is this what you are looking for?

Answer 5

If you install PECL pecl_http, you can make use of http_build_url:
http_build_url("http://www.site.com/aa/folder/page1.php",
array("path" => "folder2/page.php"));
and you pass any of your relative URI(L)s as path. The function will make sure to build the correct one.