SPUG: To sum it up... counting the number of occurences...

[Scott Blachowicz]

On Mon, Dec 18, 2000 at 02:52:36PM -0800, Jonathan Gardner wrote:
> To count the number of occurences of a rgex match in a string, I got the
> following suggestions:
> 
> $count = $string =~ tr/a//; # From several of you...
> 
> This works only if you are looking for individual characters. That isn't
> what I intended, but it was a very good solution to the example I posed. It
> is very fast, too. Trouble is that I never even think of using tr even when
> I should. It sits in the corner of my mind called "Perl Trivia" along with
> all the other stuff you can do but won't remember until someone else points
> out you should've.
> 
> $count =0;
> $string =~ s/a/ ++$count , 'a' /eg; # Thanks to Jason Lampert

What about extending that one...

	gator:~% cat ~/bin/charcount.pl
	#! /usr/bin/perl
	while (@ARGV) {
	  my $string = shift @ARGV;
	  %counts = ();
	  $string =~ s/([a-z])/++$counts{$1}, $1 /eg;
	  print "=== '$string' ===\n";
	  print map {"\t$_=$counts{$_}\n"} sort keys %counts;
	}
	gator:~% charcount.pl aldkfjasldfjasfjasldkjasdfjapirouerpowjfksdjfiaurpqej
	=== 'aldkfjasldfjasfjasldkjasdfjapirouerpowjfksdjfiaurpqej' ===
		a=7
		d=5
		e=2
		f=6
		i=2
		j=8
		k=3
		l=3
		o=2
		p=3
		q=1
		r=3
		s=5
		u=2
		w=1

Is that closer to the sort of thing you were looking for?

No idea how slow/fast it is...

-- 
Scott Blachowicz

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