This is buggy as far as scoring, but the idea is here.

#!/usr/bin/perl -w
use strict;

my $text = qq|If you have a question on how to do something in Perl, o
+r you need a Perl solution to
an actual real-life problem, or you're unsure why something you've tri
+ed just isn't 
working... then this is the place to ask.
However, you might consider asking in the chatterbox first (if you're 
+a registered user).
The response time tends to be quicker, and if it turns out that the pr
+oblem/solutions are
too much for the cb to handle, the kind monks will be sure to direct y
+ou here.|;



# build lines hash
my %lines;
my $k=1;
for (split(/\n/,$text)){
    $lines{$k}=$_;
    $k++;
}



# score hash
# put your words here, and the value for each
my %score_guide = (
    'for'=>1,
    'the'=>1,
    'if'=>2,
    'you'=>3,
    'moguai'=>40
);


# this will hold key= line num, val= score
my %score_results =();


# score each line
for (keys %lines){
    $score_results{$_} = score_line($lines{$_});
}


# feedback
for (keys %score_results){
    print "line $_ score $score_results{$_}\n";
}







sub score_line {
    my ($string)=$_[0]; # 
    
    my $score=0;
    
    
    for (sort keys %score_guide){
        
        while ($string=~s/\b\Q$_\E\b//i){ # corrected by ikegami
            $score+=$score_guide{$_};
        }
    }
    
    return $score;
}
[download]

output:

[leo@mescaline ~]$ perl scorelines.pl
line 1 score 8
line 2 score 6
line 3 score 1
line 4 score 9
line 5 score 4
line 6 score 6
[download]