PHP get specific string from url before and after unknown characters - php

Question

I know it may sound as a common question but I have difficulty understanding this process.
So I have this string:
http://domain.com/campaign/tgadv?redirect
And I need to get only the word "tgadv". But I don't know that the word is "tgadv", it could be whatever.
Also the url itself may change and become:
http://domain.com/campaign/tgadv
or
http://domain.com/campaign/tgadv/
So what I need is to create a function that will get whatever word is after campaign and before any other particular character. That's the logic..
The only certain thing is that the word will come after the word campaign/ and that any other character that will be after the word we are searching is a special one ( i.e. / or ? )
I tried understanding preg_match but really cannot get any good result from it..
Any help would be highly appreciated!

Answer 1

I would not use a regex for that. I would use parse_url and basename:
$bits = parse_url('http://domain.com/campaign/tgadv?redirect');
$filename = basename($bits['path']);
echo $filename;
However, if want a regex solution, use something like this:
$pattern = '~(.*)/(.*)(\?.*)~';
preg_match($pattern, 'http://domain.com/campaign/tgadv?redirect', $matches);
$filename = $matches[2];
echo $filename;

Answer 2

Actually, preg_match sounds like the perfect solution to this problem. I assume you are having problems with the regex?
Try something like this:
<?php
$url = "http://domain.com/campaign/tgadv/";
$pattern = "#campaign/([^/\?]+)#";
preg_match($pattern, $url, $matches);
// $matches[1] will contain tgadv.

Answer 3

$path = "http://domain.com/campaign/tgadv?redirect";
$url_parts = parse_url($path);
$tgadv = strrchr($url_parts['path'], '/');

Answer 4

You don't really need a regex to accomplish this. You can do it using stripos() and substr().
For example:
$str = '....Your string...';
$offset = stripos($str, 'campaign/');
if ( $offset === false ){
//error, end of h4 tag wasn't found
}
$offset += strlen('campaign/');
$newStr = substr($str, $offset);
At this point $newStr will have all the text after 'campaign/'.
You then just need to use a similar process to find the special character position and use substr() to strip the string you want out.

Answer 5

You can also just use the good old string functions in this case, no need to involve regexps.
First find the string /campaign/, then take the substring with everything after it (tgadv/asd/whatever/?redirect), then find the next / or ? after the start of the string, and everything in between will be what you need (tgadv).