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Subject: Re: Count number of times matched
Date: Thu, 1 Dec 2005 15:39:41 +0100
To: beginners perl <beginn...@perl.org>
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From: f...@hashref.com (Xavier Noria)

On Dec 1, 2005, at 15:13, SG Edwards wrote:

> Hi folks,
>
> If I want to count the number of times that a match occurs in a  
> line is there a way of doing this, if there is I have not found it!
>
> e.g.
> $line="This is a sentence about matching sentences.\n";
>
> $line=~/sentence/ig;

If you just want to count occurrences you can use a counter:

     my $c = 0;
     ++$c while $line =~ /sentence/g;

There's a shorter idiom that takes advantage of the way list  
assignments work in scalar context that involves something known as  
the "goatse operator" (that's jargon it's not a real operator):

     my $c =()= $line =~ /sentence/g;

but you have to choose which one is more easy to understand for you.

> Is there a way to automatically capture each individual match (e.g.  
> using a special array character?)

I don't know whether this is what you ask for, but m//g in list  
context returns the captures in one shot:

     my @tags = $html =~ /<(\w+)/g;

That is documented in perlop.

-- fxn