When listening to my MP3 collection I like some variety so I have winamp/mpg123 set onto random play.
Sometimes I would like the music to complement my mood so I set about writing a quick program to create a playlist for each genre:

#! /usr/bin/perl
# mp3genre.pl - Program to generate playlist files by genre
use File::Find;
use MP3::Info;
use MP3::Info qw(:genres);
use strict;
use_winamp_genres();

my %songsdb;
my $searchdir=$ARGV[0] or die "Enter the starting directory as a param
+eter";
print "Scanning $searchdir and subdirectories for mp3s\n";
find (\&readtag,$searchdir);
mkdir "genres" if !-e "genres";

foreach my $genre (keys %songsdb){
    my $genreclean=$genre;
    $genreclean =~ s#(/|\\)#-#g;
    print "writing $genreclean.m3u\n";
    open OUTFILE,">genres/$genreclean.m3u" or die " can't open $genre.
+m3u for output";
    print OUTFILE join("\n",@{$songsdb{$genre}});
    close OUTFILE;
}

print "\nAll done, give me a cookie.\n";

sub readtag{
    my $file=$File::Find::name;
    if ($file =~ m/\.mp3$/){
        my $tag = get_mp3tag($file);
        push @{$songsdb{$tag->{GENRE}||"none"}},$file;
    }
};
[download]

Usage is
mp3genre.pl directory
The program will search the given directory (and all subdirectories), create a "genres" folder and save a playlist for each genre in it with the filename "genre.m3u".

Any comments/criticism on the coding are welcome - thanks.