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

my %data;
my $last = 0;
while ( <DATA> ) {
    chomp;
    my @names = split;
    $last = @names if @names > $last;
    $_ = ucfirst lc $_ for @names;
    $data{ "@names" } = \@names;
}

for my $index ( 0 .. $last ) {
    for my $person ( keys %data ) {
        next if ! $data{$person}[$index];
        my $old_name = $data{$person}[$index];
        for my $length ( 1 .. length $old_name ) {
            $data{$person}[$index] = substr( $old_name, 0, $length );
            my $match = 0;
            for ( keys %data ) {
                next if $_ eq $person || @{$data{$_}} != @{$data{$pers
+on}};
                my $test_name = $data{$_}[$index];
                $data{$_}[$index] = substr( $test_name, 0, $length );
                my ($s_name , $s_test) = ("@{$data{$person}}", "@{$dat
+a{$_}}");
                $data{$_}[$index] = $test_name;
                if ( $s_name eq $s_test ) {
                    $match = 1;
                    last;
                }
            }
            last if ! $match;
        }
    }
}
print "@{ $data{$_} } =>\n" for keys %data;
[download]

__DATA__
Victor Mcduffie
Viola Mcnamee

# Yours
Vic Mcd
Vio Mcn

# Mine
V Mcn
V Mcd
[download]

Cheers - L~R

Bingo, yours is now better than mine. :)

++

EdwardG,
Here is the longer, but more elegant code I mentioned.

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

my %data = map { chomp; $_ => [ split ] } <DATA>;
my $last = 0;
for ( keys %data ) {
    $last = @{$data{$_}} if @{$data{$_}} > $last;
    $_ = ucfirst lc $_ for @{$data{$_}};
}

for my $index ( 0 .. $last ) {
    for my $name ( map { $data{$_} } keys %data ) {
        next if ! $name->[$index];
        for my $length ( 1 .. length $name->[$index] ) {
            if ( ! Match( $name, $index, $length ) ) {
                $name->[$index] = substr( $name->[$index], 0, $length 
+) ;
                last;
            }
        }
    }
}

sub Short {
    my ( $name, $index, $length ) = @_;
    return join " ",
        @{$name}[ grep $_ < $index, 0 .. $#$name ],
        substr( $name->[$index], 0, $length ),
        @{$name}[ grep $_ > $index, 0 .. $#$name];
}

sub Match {
    my ( $name, $index, $length ) = @_;
    my $s_name = Short( $name, $index, $length );
    for my $t_name ( map { $data{$_} } keys %data ) {
        next if @$name != @$t_name || $name eq $t_name;
        my $s_test = Short( $t_name, $index, $length );
        return 1 if $s_name eq $s_test;
    }
    return 0;
}
print "@{ $data{$_} } => $_\n" for sort keys %data;
[download]

If you want it to be even faster, add the following test as the second || condition on line 36.

index($t_name->[$index], substr($name->[$index], 0, 1))
[download]

Cheers - L~R