use Perl

Here's one of the tasks I came across with: a bunch of files in a directory (almost 200), of which I know some of them are the same; I just don't know which ones.

Here's samefile, the script I created to find those files:

#!/usr/bin/perl
use strict;
use warnings;
use File::Compare;
use Getopt::Std;

our %opts = get_options();

show_help()             if $opts{h};
show_version()          if $opts{V};

get_sizes();
find_copies();

# subroutines

sub find_copies {
  our %sizes;
  for (values %sizes) {
    my @files = @{$_};

    while (my $f = shift @files) {
      @files || next;
      my @copies = grep {! compare($f, $_)} @files or next;
      print "\"$f\"", (map {" \"$_\""} @copies), "\n";
      for my $s (@copies) {@files = grep {$_ ne $s} @files}
      }
  }
}

sub get_sizes {
  our %sizes;
  for (@ARGV) {
    if (-f) {
      push @{$sizes{(stat)[7]}}, $_;
    }
    elsif ($opts{r} && -d) {
      push @ARGV, <"$_/*">;
      }
  }
}

sub get_options {
  my %opts;
  getopts('rhV', \%opts );

  for my $key ( keys %opts ) {
    $opts{$key} = 1 unless defined $opts{$key}
  }

  %opts;
}

sub show_help {
  die "Usage: samefile file1 file2
 or:   samefile -r *
samefile: identifies equal files

Options:
  -h         displays this messages and exit
  -r         recursive mode
  -v         show version and exit
"
}

sub show_version {
  die "samefile version 0.01\n";
}

It currently prints something like this:

$ samefile *
"file1" "file3" "file6"
"file4" "file5"

Meaning that file1, file3 and file6 are all alike and likewise for file4 and file5.

Comments on the output or anything else are welcome...