Regular expressions help...

gazchap

Hi all.

I'm a complete newbie when it comes to regular expressions, and I'm finding them a tad confusing.

I'm trying to do two things, both with a snippet of text that has this format (replace curly brackets with square brackets)

{URL=http://www.blah.com}Link Text Here{/URL}

The first thing I'm trying to do, and have done (although how well I don't know) is to strip the URL tags, just leaving the Link Text Here. The reg.exp I've used for this is

/\[(.|\s)*?\]/

The second thing i'm trying to do is to get the URL out of it, i.e. [url]http://www.blah.com,[/url] stripping everything else. This I'm stuck on.

Can anyone enlighten me? 🙂 And at the same time, perhaps point me in the direction of some half-decent RE tutorials? 🙂

Muchos gracias.

BSTRhino

Um, I'd like to comment on your expression, I don't understand why you would match any character, or a space character, because the \s is already a subset of the '.' character, isn't it?

gazchap

I don't know to be honest, like I said, complete newbie 🙂

I think I read somewhere that including \s would stop newlines from breaking the expression?

tbach2

don't outsmart yourself-- what must always be checked for?

[ URL =
]
[ /URL ]

therefore I would start with something like this

$pattern = "/\[URL=(.*)\](.*)\[\/URL\]/";

of course, the problem of greediness comes in, so I tried this logic:

Match [ URL=
match all not ] characters
match ]
match all not [ characters
match [ /URL]
[/list=1]This is what I came up with:
```
"/\[URL=([^\]]*)\]([^\[]*)\[\/URL\]/"
```
note that this is case sensitive; you'll need to do a bit more research to make it smoother.

BSTRhino

I learnt regular expressions from Perl, so I might be a bit wrong in cases.

I believe \s means match any whitespace, like a space, tab or newline.