On Mon, 17 Jan 2005, Alexander Blüm wrote:
> this is also possible _without_ any modules, except maybe "strict".
>
> # this will replace the contents of each match in @get
> foreach(@array){
> my @get = $_ =~ /<a href="(.*?)">/g;
> }
What happens if the url has a doublequote followed by an angle bracket?
It's not likely, but it can happen, and it can work.
And if such a URL is discovered, this regex would break.
What happens if the url isn't wrapped in quotes at all?
This is much more likely, and again will work fine in browsers.
But again, this regex won't find it at all.
This kind of problem is why HTML (and XML) is really best processed
using pre-written parser modules, such as HTML::SimpleLinkExtor. A
parser has a much better shot at getting a proper view of the document
than a simple regex pattern match.
Yes, you can approach such problems using simple regular expressions,
such as what we have here, and in many cases they'll work, and maybe
even work faster than the parser version would. On the other hand, this
approach is much less generally robust: minor changes that don't break
the HTML may break the regex, so you end up having to constantly adjust
it to handle all the special cases that come up over time.
If you just parse it at the outset, such as with HTML::SimpleLinkExtor,
then the code should be simple, robust, and useful for a long time.
--
Chris Devers
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