http://paperlined.org/dev/src/pl/git_characterize_files/file_survey.pl

#!/usr/bin/perl

# use the program 'file' to try to classify files in ./target/

    use strict;
    use warnings;

    use Data::Dumper;
    #use Devel::Comments;           # uncomment this during development to enable the ### debugging statements


chdir "target";

my %filetypes;


open my $pin, '-|', 'find', '.', '-type', 'f'          or die $!;
while (<$pin>) {
    chomp;
    next if (grep {$_ eq '.git'} split '/');
    my $filetype = readpipe_args('file', '-b', $_);
    chomp $filetype;
    push(@{$filetypes{$filetype}}, $_);
}
#print Dumper \%filetypes;

my %counts = map {$_ => scalar(@{$filetypes{$_}})} keys %filetypes;
#print Dumper \%counts;

foreach my $filetype (sort {$counts{$b} <=> $counts{$a}} keys %counts) {
    print "================ $filetype ================\n";
    print join("\n", sort @{$filetypes{$filetype}}), "\n\n";
}

print "\n";
print "================ file type count ================\n";
my @sort = sort {
            $counts{$b} <=> $counts{$a}
            || $a cmp $b
        } keys %counts;
my $total = 0;
foreach my $filetype (@sort) {
    printf "%-5d  %s\n", $counts{$filetype}, $filetype;
    $total += $counts{$filetype};
}
printf "%-5d  total\n", $total;




# like qx// or readpipe(), BUT it allows you to give explicitely delimited args, so you don't have to worry about escaping quotes
sub readpipe_args {my$p=open(my$f,'-|',@_)or die$!;my@o=<$f>;close$f;waitpid($p,0);wantarray?@o:join("",@o)}