#!/usr/bin/env perl

use v5.10;
use warnings;

open my $fh, "-|", "git ls-tree -r HEAD"
  or die $!;

my %fs_sha1_path;

while ( my $line= <$fh> ) {
    chomp $line;

    if ( $line =~ m{ \A \d+ \s+ \w+ \s+ (\w+) \s+ (.*) \z }x ) {
        my ( $sha1, $path )= ($1, $2 );
        if ( -f $path and !-l $path ) {
            my $fs= -s $path;
            $fs and push @{ $fs_sha1_path{ $fs }{ $sha1 } }, $path;
        };
    }
}

for my $fs ( sort { $a <=> $b } keys %fs_sha1_path ) {
    for my $sha1 ( sort keys %{ $fs_sha1_path{ $fs } } ) {
       if ( @{ $fs_sha1_path{ $fs }{ $sha1 } } > 1 ) {
           for my $path ( sort @{ $fs_sha1_path{ $fs }{ $sha1 } } ) {
               say sprintf "%10d %s..%s %s",
                 $fs, substr($sha1,0,7), substr($sha1,-3), $path;
            }
            say '-', ' -' x 39;
        }
    }
}

exit;

__END__