#!/usr/bin/perl
use File::Find;

use strict;
use warnings;

finddepth (\&recursive, "./");

sub recursive
    {
        push @path, "$File::Find::dir/";
        push @files, $_;
    }

@files = File::Spec->no_upwards( @files );
my @newname;
foreach my $file (@files)
    {
        my (@parts, @name);
        push @name, split(/\./,$file);

        foreach my $piece (@name)
            {
                unless ( ($piece =~ /[[:alpha:]]/ && $piece =~ /[[:digit:]]/) ){
                    $piece = substr $piece, 0, 1;
                }
                push @parts, $piece;
            }
        push @newname, join('.',@parts);
    }

my %h = ();
@newname = map { s/(\d*)$/$1 + 1/e while $h{$_}; $h{$_}++; $_ } @newname;

pop @path;

my @from = @path;
for my $i (0..$#path) { $from[$i] .= $files[$i] } \@from;

my @to = @path;
for my $i (0..$#path) { $to[$i] .= $newname[$i] } \@to;


sub first_char { substr( shift, 0, 1) }
sub assemble ( join '.', @_ }