PHP REGEX: Get domain from URL

Question 1

What I want

I want to get from a URL the domain part so from http://example.com/ -> example.com

Examples:

+----------------------------------------------+-----------------------+
| input                                        | output                |
+----------------------------------------------+-----------------------+
| http://www..com/questions/ask   | www..com |
| http://validator.w3.org/check                | validator.w3.org      |
| http://www.google.com/?q=hello               | www.google.com        |
| http://google.de/?q=hello                    | google.de             |
+----------------------------------------------+-----------------------+

I found some related questions in but none of them was exactly what I was looking for.

Thanks for any help!

Question 2

There's no need to use a regex for this. PHP has an inbuilt function to do just this. Use parse_url():

$domain = parse_url($url, PHP_URL_HOST);

Question 3

John Gruber, of Daring Fireball fame, had a post recently that detailed his quest for a good URL-recognizing regex string. What he came up with was this:

b(([w-]+://?|www[.])[^s()<>]+(?:([wd]+)|([^[:punct:]s]|/)))

Which apparently does OK with Unicode-containing URLs, as well. You'd need to do the slight modification to it to get the rest of what you're looking for -- the scheme, username, password, etc. Alan Storm wrote a piece explaining Gruber's regex pattern, which I definitely needed (regex is so write-once-have-no-clue-how-to-read-ever-again!).

Question 4

According to the documentation:

preg_match_all — Perform a global regular expression match

Since you are after just one, you should be using preg_match:

Perform a regular expression match

$regex = '/https?://[^" ]+/i';
$string = "lorem ipsum http://google.com lorem ipusm dolor http://yahoo.com/something";
preg_match($regex, $string, $matches);
echo $matches[0];

Yields:

http://google.com

Question 5

Have your complete .htaccess like this:

  Options +FollowSymLinks -MultiViews
  # Turn mod_rewrite on
  RewriteEngine On
  RewriteBase /

  ## don't touch /forum URIs
  RewriteRule ^forums/ - [L,NC]

  RewriteCond %{THE_REQUEST} s/+products(?:.php)??id=([0-9]+) [NC]
  RewriteRule ^ products/%1? [R,L]

  RewriteRule ^products/([0-9]+)/?$ products.php?id=$1 [L,QSA]

  ## hide .php extension snippet
  # To externally redirect /dir/foo.php to /dir/foo
  RewriteCond %{THE_REQUEST} s([^.]+).php [NC]
  RewriteRule ^ %1 [R,L]

  # To internally forward /dir/foo to /dir/foo.php
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME}.php -f
  RewriteRule ^(.+?)/?$ $1.php [L]

Question 6

You can use this regex:

#(s|^)((?:https?://)?w+(?:.w+)+(?<=.(net|org|edu|com))(?:/[^s]*|))(?=s|b)#is

Code:

$arr = array(
'http://www.domain.com/?foo=bar',
'http://www.that"sallfolks.com',
'This is really cool site: https://www.domain.net/ isn't it?',
'http://subdomain.domain.org',
'www.domain.com/folder',
'Hello! You can visit vertigofx.com/mysite/rocks for some awesome pictures, or just go to vertigofx.com by itself',
'subdomain.domain.net',
'subdomain.domain.edu/folder/subfolder',
'Hello! Check out my site at domain.net!',
'welcome.to.computers',
'Hello.Come visit oursite.com!',
'foo.bar',
'domain.com/folder',

);
foreach($arr as $url) {   
   $link = preg_replace_callback('#(s|^)((?:https?://)?w+(?:.w+)+(?<=.(net|org|edu|com))(?:/[^s]*|))(?=s|b)#is',
           create_function('$m', 'if (!preg_match("#^(https?://)#", $m[2]))
               return $m[1]."<a href="http://".$m[2]."">".$m[2]."</a>"; else return $m[1]."<a href="".$m[2]."">".$m[2]."</a>";'),
           $url);
   echo $link . "n";

OUTPUT:

<a href="http://www.domain.com/?foo=bar">http://www.domain.com/?foo=bar</a>
http://www.that"sallfolks.com
This is really cool site: <a href="https://www.domain.net">https://www.domain.net</a>/ isn't it?
<a href="http://subdomain.domain.org">http://subdomain.domain.org</a>
<a href="http://www.domain.com/folder">www.domain.com/folder</a>
Hello! You can visit <a href="http://vertigofx.com/mysite/rocks">vertigofx.com/mysite/rocks</a> for some awesome pictures, or just go to <a href="http://vertigofx.com">vertigofx.com</a> by itself
<a href="http://subdomain.domain.net">subdomain.domain.net</a>
<a href="http://subdomain.domain.edu/folder/subfolder">subdomain.domain.edu/folder/subfolder</a>
Hello! Check out my site at <a href="http://domain.net">domain.net</a>!
welcome.to.computers
Hello.Come visit <a href="http://oursite.com">oursite.com</a>!
foo.bar
<a href="http://domain.com/folder">domain.com/folder</a>

PS: This regex only supports http and https scheme in URL. So eg: if you want to support ftp also then you need to modify the regex a little.

PHP REGEX: Get domain from URL

Answers

php,regex,url,dns