Creating 'slash' links

[bob_the_coder]

Hey all, I'm not really sure what this is technically called, but I'm working on a small application and need to be able to "link" issue tickets to each other. What I have is a comment string, lets go with "this is very similar to /issue/14001, can probably be deleted" I'd like to replace "/issue/14001" with "<a href='viewissue.php?id=14001'>14001</a>".

 

I can do a str_replace to replace the /issue/ but I can't seem to figure out how to get the 14001 part of the string.... I'm guessing it's some kind of Regex, but I can not figure it out at all. I'm hoping someone here could give me a hand.

 

Thanks for any help that can be provided,

BTC

[kicken]

If the /issue/ part is constant and only the number varies then you would use a regex like this:

$str = preg_replace('~\b/issue/(\d+)\b~', '<a href="/issue/$1">/issue/$1</a>', $str);

That will find any instance of /issue/ followed by a sequence of digits and replace it with the link. The $1 in the replacement string is a back-reference to the first parenthesized group which is the issue number.

[bob_the_coder]

hmm, I have no idea how that's supposed to work. I just tried it and it's not working. Regex is not my strong suit.

[.josh]

 

@kicken that first word boundary won't work, because " /issue.." has 2 non-word chars in a row (the space and then forward slash).

 

IOW it has to be [non-word char]\b[word char]

[.josh]

Basically you need to do this, which will match no matter what comes before it:

 

$str = preg_replace('~/issue/(\d+)\b~i', '<a href="/issue/$1">/issue/$1</a>', $str);

Or this, which uses a negative lookbehind as a workaround for what kicken posted. (it will only match if it's preceded by a non-word char):

 

$str = preg_replace('~(?<=\W)/issue/(\d+)\b~i', '<a href="/issue/$1">/issue/$1</a>', $str);

I also threw in a case-insensitive modifier so it will match if someone does /ISSUE/123

[bob_the_coder]

Thanks Josh, the first suggestion worked perfectly. Thank you both for your help. I really appreciate it. -Bob