Re: Capture only first match in regular expression

Zapanaz <http://joecosby.com/code/mail.pl> wrote:
>
>The answer to this is probably staring me in the face ...
>
>I am parsing/page scraping some HTML. I know the first anchor tag <a>
>contains information I want.
>
>So I do this:
>
> if($content =~ /.*(<a.*<\/a>).*/i){
> $anchorContent = $1;
>
>This basically works the way I want, it matches an anchor tag and
>captures the content of it.
>
>But there are multiple anchor tags in the HTML. What I want is the
>first one, but what I get is the last one.

Drop that .* at the beginning of your RE, it doesn't do you any good but
eats up everything as far as it can provided the following RE still
matches (in short: it is greedy).

Having said that unless your HTML is some fixed format you really
really should be using an HTML parser to parse HTML. HTML is not a
regular language and therefore cannot be parsed using pure regular
expressions.

>I think I should be using one of these
>
>* Match 0 or more times
>+ Match 1 or more times
>? Match 1 or 0 times
>{n} Match exactly n times
>{n,} Match at least n times
>{n,m} Match at least n but not more than m times

If at all you could use ? to turn the * into non-greedy as in .*?, but
that's just stupid because it would match the empty string anywhere.

jue

Jürgen Exner