+#!/usr/bin/perl
+use warnings;
+use strict;
+
+use Getopt::Std;
+use File::Basename;
+use File::Copy;
+use MP3::Tag;
+use Ogg::Vorbis::Header;
+
+# documentation {{{
+=head1 NAME
+
+arename.pl - automatically rename audio files by tagging information
+
+=head1 SYNOPSIS
+
+arename.pl [OPTION(s)] FILE(s)...
+
+=head1 OPTIONS AND ARGUMENTS
+
+=over 8
+
+=item B<-d>
+
+Go into dryrun mode.
+
+=item B<-f>
+
+Overwrite files if needed.
+
+=item B<-h>
+
+Display a short help text.
+
+=item B<-V>
+
+Display version infomation.
+
+=item B<-v>
+
+Enable verbose output.
+
+=item B<-p> E<lt>prefixE<gt>
+
+Define a prefix for destination files.
+
+=item B<-T> E<lt>templateE<gt>
+
+Define a compilation template.
+
+=item B<-t> E<lt>templateE<gt>
+
+Define a generic template.
+
+=item I<FILE(s)...>
+
+Input files, that are subject for renaming.
+
+=back
+
+=head1 DESCRIPTION
+
+B<arename.pl> is a tool that is able to rename audio files by looking at
+a file's tagging information, from which it will assemble a consistent
+destination file name. The format of that filename is configurable for the
+user by the use of template strings.
+
+B<arename.pl> currently supports two widely used audio formats, namely
+MPEG Layer3 and ogg vorbis. The format, that B<arename.pl> will assume
+for each input file is determined by the file's filename-extension
+(I<.mp3> vs. I<.ogg>). The extension check is case-insensitive.
+
+By default, B<arename.pl> will refuse to overwrite destination files,
+if the file in question already exists. You can force overwriting by
+supplying the B<-f> option.
+
+=head1 FILES
+
+B<arename.pl> uses up to two configuration files. As for most programs,
+the script will try to read a configuration file, that is located in the
+user's I<home directory>. In addition to that, it will try to load I<local>
+configuration files, if it finds appropriately named files in the
+I<current directory>.
+
+=over 8
+
+=item B<~/.arenamerc>
+
+per-user global configuration file.
+
+=item B<./.arename.local>
+
+per-directory local configuration file.
+
+=back
+
+=head2 File format
+
+The format of the aforementioned files is pretty simple.
+It is parsed line by line. Empty lines, lines only containing whitespace
+and lines, whose first non whitespace character is a hash character (I<#>)
+are ignored.
+
+Each line consists of one or two parts. If there are two parts,
+they are separated by whitespace. The first part of the line will be used
+as the identifier of a setting (eg. I<verbose>). The second part (read: the
+rest of the line) is used as the value of the setting. (No quoting, or whatsoever
+is required.)
+
+If a line consists of only one part, that means the setting is switched on.
+
+=head2 Configuration file example
+
+ # switch on verbosity
+ verbose
+
+ # the author is crazy! use a sane template by default. :-)
+ template &artist - &album (&year) - &tracknumber. &tracktitle
+
+=head1 SETTINGS
+
+The following settings are supported in all configuration files:
+
+=over 8
+
+=item B<comp_template>
+
+Defines a template to use with files that provide a compilation tag
+(for 'various artist' CDs, for example). This setting can still be
+overwritten by the B<-T> command line option. (default value:
+I<va/&album/&tracknumber - &artist - &tracktitle>)
+
+=item B<default_year>
+
+Defines a default year, for files, that lack this information.
+(default value: I<undefined>)
+
+=item B<prefix>
+
+Defines a prefix for destination files. This setting can still be
+overwritten by the B<-p> command line option. (default value: I<.>)
+
+=item B<sepreplace>
+
+Tagging information strings may contain slashes, which is a pretty bad
+idea on most filesystems. Therefore, you can define a string, that replaces
+slashes with the value of this setting. (default value: I<_>)
+
+=item B<template>
+
+Defines a template to use with files that do not provide a compilation tag
+(or where the compilation tag and the artist tag are exactly the same).
+This setting can still be overwritten by the B<-T> command line option.
+(default value: I<&artist[1]/&artist/&album/&tracknumber - &tracktitle>)
+
+=item B<tnpad>
+
+This defines the width, to which the tracknumber field is padded with zeros
+on the left. (default value: I<2>)
+
+=item B<verbose>
+
+Switches on verbosity by default. (default value: I<off>)
+
+=back
+
+=head1 TEMPLATE FORMAT
+
+B<arename.pl>'s templates are quite simple, yet powerful.
+
+At simplest, a template is just a fixes character string. However, that would
+not be exactly useful. So, the script is able to expand certain expressions
+with information gathered from the file's tagging information.
+
+The expressions can have two slightly different forms:
+
+=over 8
+
+=item B<&>I<identifier>
+
+The simple form.
+
+=item B<&>I<identifier>B<[>I<length>B<]>
+
+The "complex" form. The I<length> argument in square brackets defines the
+maximum length, to which the expression should be expanded.
+
+=back
+
+=head2 Available expression identifiers
+
+The data, that is expanded is derived from tagging information in
+the audio files. For I<.ogg> files, the tag checking B<arename.pl> does
+is case insensitive and the first matching tag will be used.
+
+=over 8
+
+=item B<album>
+
+Guess.
+
+=item B<artist>
+
+Guess again.
+
+=item B<compilation>
+
+For I<.ogg> this is filled with information found in the 'albumartist' tag.
+For I<.mp3> this is filled with information from the id3v2 TPE2 frame.
+If the mp3 file only provides a id3v1 tag, this is not supported.
+
+=item B<tracknumber>
+
+The number of the position of the track on the disc. Obviously. However, this
+can be in the form of '12' or '12/23'. In the second form, only the part left
+of the slash is used. The tracknumber is a little special, as you can defined
+to what width it should be padded with zeros on the left (see I<tnpad> setting
+in L<arename(1)/SETTINGS>).
+
+=item B<tracktitle>
+
+Well...
+
+=item B<year>
+
+Year (id3v1), TYER (id3v2) or DATE tag (.ogg).
+
+=back
+
+=head1 SEE ALSO
+
+L<Ogg::Vorbis::Header(3)> and L<MP3::Tag(3)>.
+
+=head1 AUTHOR
+
+Frank Terbeck E<lt>ft@bewatermyfriend.orgE<gt>,
+
+Please report bugs.
+
+=head1 LICENSE
+
+ Copyright 2007
+ Frank Terbeck <ft@bewatermyfriend.org>, All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ 1. Redistributions of source code must retain the above
+ copyright notice, this list of conditions and the following
+ disclaimer.
+ 2. Redistributions in binary form must reproduce the above
+ copyright notice, this list of conditions and the following
+ disclaimer in the documentation and/or other materials
+ provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS OF THE
+ PROJECT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+=cut
+#}}}
+# variables {{{
+my (
+ %defaults, %methods, %opts,
+ $dryrun, $comp_template, $force, $prefix,
+ $sepreplace, $template, $tnpad, $verbose
+);
+my ($NAME, $VERSION) = ( 'arename.pl', 'v0.3' );
+#}}}
+sub apply_defaults { #{{{
+ my ($datref) = @_;
+
+ foreach my $key (keys %defaults) {
+ if (!defined $datref->{$key}) {
+ if ($verbose) {
+ print " -!- Setting ($key) to \"$defaults{$key}\".\n";
+ }
+ $datref->{$key} = $defaults{$key};
+ }
+ }
+}
+#}}}
+sub arename { #{{{
+ my ($file, $datref, $ext) = @_;
+ my ($t, $newname);
+
+ apply_defaults($datref);
+
+ if ($verbose) { #{{{
+ print " -!- Artist : \"" .
+ (defined $datref->{artist} ? $datref->{artist} : "-.-")
+ . "\"\n";
+ print " -!- Compilation: \"" .
+ (defined $datref->{compilation} ? $datref->{compilation} : "-.-")
+ . "\"\n";
+ print " -!- Album : \"" .
+ (defined $datref->{album} ? $datref->{album} : "-.-")
+ . "\"\n";
+ print " -!- Tracktitle : \"" .
+ (defined $datref->{tracktitle} ? $datref->{tracktitle} : "-.-")
+ . "\"\n";
+ print " -!- Tracknumber: \"" .
+ (defined $datref->{tracknumber} ? $datref->{tracknumber} : "-.-")
+ . "\"\n";
+ print " -!- Year : \"" .
+ (defined $datref->{year} ? $datref->{year} : "-.-")
+ . "\"\n";
+ } #}}}
+
+ if (defined $datref->{compilation}
+ && $datref->{compilation} ne $datref->{artist}) {
+
+ $t = $comp_template;
+ } else {
+ $t = $template;
+ }
+
+ $newname = expand_template($t, $datref);
+ if (!defined $newname) {
+ return;
+ }
+
+ $newname = $prefix . '/' . $newname . '.' . $ext;
+
+ if (file_eq($newname, $file)) {
+ print " -!- ($file)\n would stay the way it is, skipping.\n";
+ return;
+ }
+
+ if (-e $newname && !$force) {
+ print " -!- ($newname) exists.\n use '-f' to force overwriting.\n";
+ return;
+ }
+
+ ensure_dir(dirname($newname));
+
+ print " -!- mv '$file' \\\n" .
+ " '$newname'\n";
+
+ if (!$dryrun) {
+ xrename($file, $newname);
+ }
+}
+#}}}
+sub ensure_dir { #{{{
+ # think: mkdir -p /foo/bar/baz
+ my ($wantdir) = @_;
+ my (@parts, $sofar);
+
+ if (-d $wantdir) {
+ return;
+ }
+
+ if ($wantdir =~ '^/') {
+ $sofar = '/';
+ } else {
+ $sofar = '';
+ }
+
+ @parts = split(/\//, $wantdir);
+ foreach my $part (@parts) {
+ if ($part eq '') {
+ next;
+ }
+ $sofar = (
+ $sofar eq ''
+ ? $part
+ : (
+ $sofar eq '/'
+ ? '/' . $part
+ : $sofar . "/" . $part
+ )
+ );
+
+ if (!-d $sofar) {
+ if ($dryrun || $verbose) {
+ print " -!- mkdir \"$sofar\"\n";
+ }
+ if (!$dryrun) {
+ mkdir($sofar) or die " -!- Could not mkdir($sofar).\n" .
+ " -!- Reason: $!\n";
+ }
+ }
+ }
+}
+#}}}
+sub expand_template { #{{{
+ my ($template, $datref) = @_;
+ my @tags = (
+ 'album',
+ 'artist',
+ 'compilation',
+ 'tracknumber',
+ 'tracktitle',
+ 'year'
+ );
+
+ foreach my $tag (@tags) {
+ my ($len, $token);
+
+ while ($template =~ m/&$tag(\[(\d+)\]|)/) {
+ $len = 0;
+ if (defined $2) { $len = $2; }
+
+ if (!defined $datref->{$tag} || $datref->{$tag} eq '') {
+ warn " -!- $tag not defined, but required by template. Giving up.\n";
+ return undef;
+ }
+
+ if ($len > 0) {
+ $token = substr($datref->{$tag}, 0, $len);
+ } else {
+ if ($tag eq 'tracknumber') {
+ my $val;
+ if ($datref->{$tag} =~ m/^([^\/]*)\/.*$/) {
+ $val = $1;
+ } else {
+ $val = $datref->{$tag};
+ }
+ $token = sprintf "%0" . $tnpad . "d", $val;
+ } else {
+ $token = $datref->{$tag};
+ }
+ }
+ if ($token =~ m!/!) {
+ if ($verbose) {
+ print " -!- Found directory seperator in token.\n";
+ print " -!- Replacing with \"$sepreplace\".\n";
+ }
+ $token =~ s!/!$sepreplace!g;
+ }
+ $template =~ s/&$tag(\[(\d+)\]|)/$token/;
+ }
+ }
+
+ return $template;
+}
+#}}}
+sub file_eq { #{{{
+ my ($f0, $f1) = @_;
+ my (@stat0, @stat1);
+
+ if (!-e $f0 || !-e $f1) {
+ # one of the two doesn't even exist, can't be the same then.
+ return 0;
+ }
+
+ @stat0 = stat $f0 or die "Could not stat($f0): $!\n";
+ @stat1 = stat $f1 or die "Could not stat($f1): $!\n";
+
+ if ($stat0[0] == $stat1[0] && $stat0[1] == $stat1[1]) {
+ # device and inode are the same. same file.
+ return 1;
+ }
+
+ return 0;
+}
+#}}}
+sub process_mp3 { #{{{
+ my ($file) = @_;
+ my ($mp3, %data, $info);
+
+ $mp3 = MP3::Tag->new($file);
+
+ if (!defined $mp3) {
+ print " -!- Failed to open \"$file\".\n -!- Reason: $!\n";
+ return;
+ }
+
+ $mp3->get_tags;
+
+ if (!exists $mp3->{ID3v1} && !exists $mp3->{ID3v2}) {
+ print " -!- No tag found. Ignoring.\n";
+ $mp3->close();
+ return;
+ }
+
+ if (exists $mp3->{ID3v2}) {
+ ($data{artist}, $info) = $mp3->{ID3v2}->get_frame("TPE1");
+ ($data{compilation}, $info) = $mp3->{ID3v2}->get_frame("TPE2");
+ ($data{album}, $info) = $mp3->{ID3v2}->get_frame("TALB");
+ ($data{tracktitle}, $info) = $mp3->{ID3v2}->get_frame("TIT2");
+ ($data{tracknumber}, $info) = $mp3->{ID3v2}->get_frame("TRCK");
+ ($data{year}, $info) = $mp3->{ID3v2}->get_frame("TYER");
+ } elsif (exists $mp3->{ID3v1}) {
+ print " -!- Only found ID3v1 tag.\n";
+ $data{artist} = $mp3->{ID3v1}->artist;
+ $data{album} = $mp3->{ID3v1}->album;
+ $data{tracktitle} = $mp3->{ID3v1}->title;
+ $data{tracknumber} = $mp3->{ID3v1}->track;
+ $data{year} = $mp3->{ID3v1}->year;
+ }
+
+ $mp3->close();
+
+ arename($file, \%data, 'mp3');
+}
+#}}}
+sub process_ogg { #{{{
+ my ($file) = @_;
+ my ($ogg, %data, @tags);
+
+ $ogg = Ogg::Vorbis::Header->load($file);
+
+ if (!defined $ogg) {
+ print " -!- Failed to open \"$file\".\n -!- Reason: $!\n";
+ return;
+ }
+
+ @tags = $ogg->comment_tags;
+
+ foreach my $tag (@tags) {
+ my ($realtag, $value);
+ if (!(
+ $tag =~ m/^ALBUM$/i ||
+ $tag =~ m/^ARTIST$/i ||
+ $tag =~ m/^TITLE$/i ||
+ $tag =~ m/^TRACKNUMBER$/i ||
+ $tag =~ m/^DATE$/i ||
+ $tag =~ m/^ALBUMARTIST$/i
+ )) { next; }
+
+ $value = join(' ', $ogg->comment($tag));
+ if ($tag =~ m/^ALBUM$/i) {
+ $realtag = 'album';
+ } elsif ($tag =~ m/^ARTIST$/i) {
+ $realtag = 'artist';
+ } elsif ($tag =~ m/^TITLE$/i) {
+ $realtag = 'tracktitle';
+ } elsif ($tag =~ m/^TRACKNUMBER$/i) {
+ $realtag = 'tracknumber';
+ } elsif ($tag =~ m/^DATE$/i) {
+ $realtag = 'year';
+ } elsif ($tag =~ m/^ALBUMARTIST$/i) {
+ $realtag = 'compilation';
+ } else {
+ die "This should not happen. Report this BUG. ($tag, $value)";
+ }
+
+ if (!defined $data{$realtag}) {
+ $data{$realtag} = $value;
+ }
+ }
+
+ arename($file, \%data, 'ogg');
+}
+#}}}
+sub process_warn { #{{{
+ my ($file) = @_;
+
+ warn " -!- No method for handling \"$file\".\n";
+}
+#}}}
+sub rcload { #{{{
+ my ($file, $desc) = @_;
+ my ($fh, $retval);
+ my $count = 0;
+ my $lnum = 0;
+
+ if (!open($fh, "<$file")) {
+ warn "Failed to read $desc ($file).\n -!- Reason: $!\n";
+ return 1;
+ }
+
+ print "Reading \"$file\"...\n";
+
+ while (my $line = <$fh>) {
+ chomp($line);
+ $lnum++;
+
+ if ($line =~ m/^\s*#/ || $line =~ m/^\s*$/) {
+ next;
+ }
+
+ $line =~ s/^\s*//;
+ my ($key,$val) = split(/\s+/, $line, 2);
+
+ if ($key eq 'template') {
+ $template = $val;
+ } elsif ($key eq 'comp_template') {
+ $comp_template = $val;
+ } elsif ($key eq 'default_year') {
+ $defaults{year} = $val;
+ } elsif ($key eq 'sepreplace') {
+ $sepreplace = (defined $val ? $val : "");
+ } elsif ($key eq 'tnpad') {
+ $tnpad = $val;
+ } elsif ($key eq 'verbose') {
+ $verbose = 1;
+ } elsif ($key eq 'prefix') {
+ $prefix = $val;
+ } else {
+ warn "$file,$lnum: invalid line '$line'.\n";
+ return -1;
+ }
+
+ $count++;
+ }
+ close $fh;
+
+ print " -!- Read $desc.\n -!- $count valid items.\n";
+ return 0;
+}
+#}}}
+sub xrename { #{{{
+ # a rename() replacement, that implements renames across
+ # filesystems via File::copy() + unlink().
+ # This assumes, that source and destination directory are
+ # there, because it stat()s them, to check if it can use
+ # rename().
+ my ($src, $dest) = @_;
+ my (@stat0, @stat1, $d0, $d1, $cause);
+
+ $d0 = dirname($src);
+ $d1 = dirname($dest);
+ @stat0 = stat $d0 or die "Could not stat($d0): $!\n";
+ @stat1 = stat $d1 or die "Could not stat($d1): $!\n";
+
+ if ($stat0[0] == $stat1[0]) {
+ $cause = 'rename';
+ rename $src, $dest or goto err;
+ } else {
+ $cause = 'copy';
+ copy($src, $dest) or goto err;
+ $cause = 'unlink';
+ unlink $src or goto dir;
+ }
+
+ return 0;
+
+err:
+ die " -!- Could not rename($src, $dest);\n" .
+ " -!- Reason: $cause(): $!\n";
+}
+#}}}
+# handle options {{{
+
+if ($#ARGV == -1) {
+ $opts{h} = 1;
+} else {
+ if (!getopts('dfhVvp:T:t:', \%opts)) {
+ if (exists $opts{t} && !defined $opts{t}) {
+ die " -t *requires* a string argument!\n";
+ } elsif (exists $opts{T} && !defined $opts{T}) {
+ die " -T *requires* a string argument!\n";
+ } elsif (exists $opts{p} && !defined $opts{p}) {
+ die " -p *requires* a string argument!\n";
+ } else {
+ die " Try $NAME -h\n";
+ }
+ }
+}
+
+if (defined $opts{h}) {
+ print " Usage:\n $NAME [-d,-f,-h,-V,-v,-p <prefix>,-[Tt] <template>] FILE(s)...\n\n";
+ print " -d Go into dryrun mode.\n";
+ print " -f Overwrite files if needed.\n";
+ print " -h Display this help text.\n";
+ print " -V Display version infomation.\n";
+ print " -v Enable verbose output.\n";
+ print " -p <prefix> Define a prefix for destination files.\n";
+ print " -T <template> Define a compilation template.\n";
+ print " -t <template> Define a generic template.\n";
+ print "\n";
+ exit 0;
+}
+
+if (defined $opts{V}) {
+ print " $NAME $VERSION\n";
+ exit 0;
+}
+
+#}}}
+# set defaults {{{
+
+$dryrun = 0;
+$force = 0;
+$prefix = '.';
+$sepreplace = '_';
+$tnpad = 2;
+$verbose = 0;
+$comp_template = "va/&album/&tracknumber - &artist - &tracktitle";
+$template = "&artist[1]/&artist/&album/&tracknumber - &tracktitle";
+
+#}}}
+# reading config file(s) {{{
+
+my $rc = $ENV{HOME} . "/.arenamerc";
+my $retval = rcload($rc, "arename.pl configuration");
+if ($retval < 0) {
+ die "Error(s) in \"$rc\". Aborting.\n";
+} elsif ($retval > 0) {
+ warn "Error opening configuration; using defaults.\n";
+}
+
+if (-r "./.arename.local") {
+ $rc = "./.arename.local";
+ $retval = rcload($rc, "local configuration");
+ if ($retval < 0) {
+ die "Error(s) in \"$rc\". Aborting.\n";
+ } elsif ($retval > 0) {
+ warn "Error opening local configuration.\n";
+ }
+}
+
+print "\n";
+
+#}}}
+# let cmd line options overwrite {{{
+
+if ($#ARGV == -1) {
+ die "No input files. See: $NAME -h\n";
+}
+
+if (defined $opts{f}) {
+ $force = $opts{f};
+}
+
+if (defined $opts{p}) {
+ $prefix = $opts{p};
+}
+
+if (defined $opts{t}) {
+ $template = $opts{t};
+}
+
+if (defined $opts{T}) {
+ $comp_template = $opts{T};
+}
+
+if (defined $opts{d}) {
+ $dryrun = $opts{d};
+}
+
+if (defined $opts{v}) {
+ $verbose = $opts{v};
+}
+
+undef %opts;
+
+#}}}
+# process what's left on the commandline aka. main() {{{
+%methods = (
+ '.mp3$' => \&process_mp3,
+ '.ogg$' => \&process_ogg
+);
+
+if ($dryrun) {
+ print "+++ We are on a dry run!\n";
+}
+
+if ($verbose) {
+ print "+++ Running verbose.\n";
+}
+
+if ($dryrun || $verbose) {
+ print "\n";
+}
+
+foreach my $file (@ARGV) {
+ my $done = 0;
+ print "Processing: $file\n";
+ if (-l $file) {
+ warn " -!- Refusing to handle symbolic links ($file).\n";
+ next;
+ }
+ if (! -r $file) {
+ warn " -!- Can't read \"$file\": $!\n";
+ next;
+ }
+
+ foreach my $method (sort keys %methods) {
+ if ($file =~ m!$method!i) {
+ $methods{$method}->($file);
+ $done = 1;
+ }
+ }
+
+ if (!$done) {
+ process_warn($file);
+ }
+}
+#}}}