font measurement

[preahkumpii]

I am working with manipulating text files in Perl, not with Web. I need to be able to take a given string of text, and given a font name and size (ideal other options as well), to output the length of the string in pixels (or whatever unit) as it would appear in the font. I have looked the Tk module and on the web extensively. I cannot find a clear description of its use at all. Here is my sample code:

#!/usr/bin/perl
use warnings;
use strict;

use Tk;

my $happy = "This is my example sentence";

# I want the measurement of the above string in pixels given a font fa
+ce and font size

Thanks for the help. Adam