php regex to extract specific domain with/without www http https from href

Question

im trying to check for the a tags which contains specific domain ... but this a tag might be with or without www , hhtp , https

$a = '  <a href="https://example.com"></a>
                <a href="http://www.example.com"></a> 
                <a href="http://example.com"></a> 
                <a href="https://www.example.com"></a> 
                <a href="http://example.com"></a> 
                ';
        $reg_exUrl = "/(http|https)\:\/\/(www.)?example+\.com(\/\S*)?/";

        preg_match($reg_exUrl, $a, $url) ;
        var_dump($url);

but i dont get all the links this is the output

array:2 [▼
  0 => "https://example.com"
  1 => "https"
]

also im not sure how to include href so it would only search inside href

user3783243 · Accepted Answer · 2018-05-19 19:22:03Z

3

Use a HTML parser, and then the URL parser to get the domain. From there use a regex on the limited string:

$a = '  <a href="https://example.com"></a>
                <a href="http://www.example.com"></a> 
                <a href="http://example.com"></a> 
                <a href="https://www.example.com"></a> 
                <a href="http://example.com"></a> 
                ';
$dom = new DOMDocument;
$dom->loadHTML($a);
$links = $dom->getElementsByTagName('a');
foreach($links as $link) {
    $host = parse_url($link->getAttribute('href'))['host'];
    if(!empty($host) && preg_match('/(^|\.)example\.com$/', $host)) {
         echo 'Expected domain';
    } 
}

Also to explain a bit more about what your current output was...preg_match outputs the first match found and each index is one capture group.

 $reg_exUrl = "/(http|https)\:\/\/(www.)?example+\.com(\/\S*)?/";
                 ^^^^^^^^^^        ^^^^                ^^^^^

So as displayed above you have 3 possible capture groups. You can use ?: at the start of them so it is not captured. You http|https can be simplified to https? (the ? makes the s optional.

edited May 19, 2018 at 19:22

answered May 19, 2018 at 18:58

user3783243

5,2125 gold badges27 silver badges45 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

hretic Over a year ago

thanx , i knew about that but this might give me otherexample.com/script.php?link=example.com or something like that which is not what i want

user3783243 Over a year ago

@hretic Actually (^|\.) is what you'd want. See 3v4l.org/Ihs6s I think that is all edge cases.

Casimir et Hippolyte Over a year ago

Good answer. You can also move all the test part into a function and use an XPath query, see 3v4l.org/4WZPi

Sanxofon · Accepted Answer · 2018-05-19 19:43:03Z

0

Here you have:

$a = '  <a href="https://example.com"></a>
            <a href="http://www.example.com"></a> 
            <a href="http://example.com"></a> 
            <a href="https://www.example.com"></a> 
            <a href="http://example.com"></a> 
            ';
    $reg_exUrl = "/href=\"(?:https?)\:\/\/(?:www\.)?example\.com\"/";

    preg_match_all($reg_exUrl, $a, $url) ;
    var_dump($url);

edited May 19, 2018 at 19:43

answered May 19, 2018 at 19:00

Sanxofon

99112 silver badges26 bronze badges

2 Comments

hretic Over a year ago

thanx , how you add href in there ? so it would only search inside href not the whole string

Sanxofon Over a year ago

I've updated the answer. The only thing is to escape quotes " >> \"

Octavian · Accepted Answer · 2018-05-19 18:59:34Z

-1

instead of preg_match, use preg_match_all

UPD: all url site regex:

$regex = '/href="(.*?)"/';

edited May 19, 2018 at 18:59

answered May 19, 2018 at 18:54

Octavian

1558 bronze badges

1 Comment

user3783243 Over a year ago

This will match more than example.com.

Collectives™ on Stack Overflow

php regex to extract specific domain with/without www http https from href

3 Answers 3

3 Comments

2 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related