use strict;
use warnings;
use 5.12.00;

die "usage: $0 [filename]\n" if (@ARGV > 1);

# Set required fields and determine fixed widths
my @fields = qw/Part Shape Color Size/;
my $re;
$re .= qr/(?<$_>$_\s*)/ for @fields;

my $header = <>;
die "Header must match " . join(' ', @fields) unless ($header =~ /^$re$/);
my $expected_len = length($header);

my $tmpl = join(' ', map { "A[".length($+{$_})."]" } @fields);

my %inv; # Inventory; $inv{key(%rec)}

while (<>) {
    if (length != $expected_len) {
        die sprintf("Got length of %d, expecting %d", length, $expected_len);
    }
    my @rec = map { /(.+?)\s*$/ } unpack $tmpl; # Get (trimmed) records
    my %rec = map { $_ => shift @rec } @fields;

    # Add the part to our inventory
    push @{$inv{key(%rec)}}, $rec{Part};
}

# Now print out the inventory in the desired format
for (sort keys %inv) {
    say join(' ',@{$inv{$_}}) . " - $_ - " . scalar @{$inv{$_}}; 
}

# Our custom hashing function for inventory items. Expects %rec argument
sub key { my %rec = @_; $rec{Shape} . $rec{Color} . $rec{Size}; }