Re: [bug-gawk] Use gawk and regex to stip comments from html files regex problem

[Manuel Collado]

El 29/10/2014 22:54, frank ernest escribió:
> Hello, I'm trying to use the lazy star to strip comments from html files but 
> it's not working:
> gawk '{ gsub(/<!--.*?-->/, "", $0); print $0}'
> I have to use a non greedy method so that this:
> <!-- comment one --> Important text <!-- comment2 -->
> does not be come this:
>
> See? But, despite the fact that several docs on extended regexes
> mention the fact that the lazy star works it does not work in gawk. I
> know that I might use some other tool like lynx, but I wanted to do it
> with gawk and I don't see why a perfectly fine programming language
> should fail for so simple a task.

The repeated inner subexpression should match only text fragments 
different than the closing comment mark. So you can use:

{
   gsub(/<!--([^-]|-[^-]|--[^>])*?-->/, "", $0)
   print
}

A bit cumbersome, but required by the eager policy of awk regexps.

And please take into account that comments can start in one line and end 
in a different line. But this is another story.

> Thanks

Regards.

--
Manuel Collado - http://lml.ls.fi.upm.es/~mcollado