The_Name_Game

#!/usr/local/bin/perl
#u# http://rosettacode.org/wiki/The_Name_Game
#c# 2019-03-21 <RC, 2019-03-21 >RC
#p# OK
#n# didn't change the logic, just made it more idiomatic Perl

use strict;
use warnings;
use feature 'say';
my $result;

sub printVerse {
    my $x  = ucfirst lc shift;
    my $x0 = substr $x, 0, 1;
    my $y  = $x0 =~ /[AEIOU]/ ? lc $x : substr $x, 1;
    my $b  = $x0 eq 'B' ? $y : 'b' . $y;
    my $f  = $x0 eq 'F' ? $y : 'f' . $y;
    my $m  = $x0 eq 'M' ? $y : 'm' . $y;
    $result .= "$x, $x, bo-$b\n" . "Banana-fana fo-$f\n" . "Fee-fi-mo-$m\n" . "$x!\n\n";
}

printVerse($_) for <Gary Earl Billy Felix Mary Steve>;
say $result; 

my $ref = <<'EOD';
Gary, Gary, bo-bary
Banana-fana fo-fary
Fee-fi-mo-mary
Gary!

Earl, Earl, bo-bearl
Banana-fana fo-fearl
Fee-fi-mo-mearl
Earl!

Billy, Billy, bo-illy
Banana-fana fo-filly
Fee-fi-mo-milly
Billy!

Felix, Felix, bo-belix
Banana-fana fo-elix
Fee-fi-mo-melix
Felix!

Mary, Mary, bo-bary
Banana-fana fo-fary
Fee-fi-mo-ary
Mary!

Steve, Steve, bo-bteve
Banana-fana fo-fteve
Fee-fi-mo-mteve
Steve!

EOD

use Test::More;
is ($result, $ref);
done_testing;