extract all url from a string.

[bbmak]

Are there code/function that extract all links from a string? I can't figure out the code. I am trying to extract all the <img src= from an xml, however, the links are mixed in the <description> tag. I am able to use the strip_tags() to get all description, but not the links. Can anyone help.

[cpd]

preg_replace("/<a(.*?)>|<\/a>/", "", $string); should remove any anchor tags from your text.

[ignace]

if (preg_match_all('!(href|src)="([^"]+)"!', $string, $matches)) {
    foreach ($matches[2] as $location) {
        //use $location
    }
}

[ManiacDan]

Ignace's expression is correct as long as all the URLs are "double quoted" and none are 'single quoted' or unquoted at all.  This should get all of them:

 

 

if (preg_match_all('!(href|src)=[\'"]?([^\'"\s]+)[\'"\s>]!', $string, $matches)) {
    foreach ($matches[2] as $location) {
        //use $location
    }
}

[ignace]

Ignace's expression is correct as long as all the URLs are "double quoted" and none are 'single quoted' or unquoted at all.

 

Thought about that! But didn't wanted to bother as more experienced regex guru's would surely follow up

 

Quick note to the OP:

 

[^\'"\s]+

 

means that if you have unescaped href's like:

 

http://www.domain.top/files/Report 2011.pdf

 

Which should be:

http://www.domain.top/files/Report+2011.pdf OR
http://www.domain.top/files/Report&202011.pdf

 

Would return an URL like:

 

http://www.domain.top/files/Report

[bbmak]

Thank you very much. It works great.

May I know why u use [2] in there? $matches[2] ?

 

i try [1], 1 is src, 2 is the link, 3 is error.

 

I also try

$location[0] is h

$location[1] is t

$location[2] is t

$location[3] is p

 

can you give it bit a explanation? sorry I am a newbie.

[ManiacDan]

Ignace, those URLs wouldn't work anyway since the HTML would be invalid.

 

bbmak, preg_match_all puts an array of matches into the third argument, in this case it's $matches.  $matches[0] is an array of the matches for the full pattern, then $matches[1] through $matches[9] are arrays of the sub-pattern matches, the items inside parentheses inside the expression. 

 

When you use a string like $location as an array, it becomes an array of characters, which is why you were getting the individual letters of the string as results.

 

Regular expressions as well as array access are both really  complex problems, so this is a very very basic answer.

[ignace]

Ignace, those URLs wouldn't work anyway since the HTML would be invalid.

 

Yeah, but nor the browser, the OP, or regex would care about that. Just wanted to point it out in case of the OP would had to deal with such URL's and to avoid a repeat question: "Why does this regex not match blabla".

[ManiacDan]

The browser won't care?  If I have a space in my URL...it shouldn't work.

[bbmak]

Ignace, those URLs wouldn't work anyway since the HTML would be invalid.

 

bbmak, preg_match_all puts an array of matches into the third argument, in this case it's $matches.  $matches[0] is an array of the matches for the full pattern, then $matches[1] through $matches[9] are arrays of the sub-pattern matches, the items inside parentheses inside the expression. 

 

When you use a string like $location as an array, it becomes an array of characters, which is why you were getting the individual letters of the string as results.

 

Regular expressions as well as array access are both really  complex problems, so this is a very very basic answer.

 

Thank you. icic... I run the echo '<pre>', print_r($matches, true), '</pre>'; and see all the arrays. and I see the array ( [2] => Array ) has all the links there.

Are there a website that has all the preg_match() modifiers listed? I try php.net. However, I do not understand at all. Any website explain it in simple English?

[bbmak]

what is the 2 !s stand for in the !(href|src)="([^"]+)"!  ???

[ManiacDan]

I told you already, but I'll try to explain again:

 

Regular expressions are their own language entirely.  They are not PHP, SQL, or anything else you're familiar with.

 

Inside regular expressions you can have parts of the expression wrapped in parentheses.  Those parentheses, when used in preg_match, are used as "capture groups."  Capture groups are put into the matches array as their own entries in the $matches array.