Sync Podcasts in Linux


I enjoy a good podcast when I'm completing my daily administration tasks. I also have a 4GB MuVo2 (see Figure 1) that I reserve space on for podcasts when I travel. But I downloaded shows manually, and I added and removed shows by hand as well. As a Linux user, this was unacceptable. I needed a way to automatically download and sync podcasts with my player. Nothing fancy - I didn't even need a GUI. And I certainly didn't want to use a closed-source solution. So I chose to create my own solution with Linux and Open Source software.


Figure 1: Creative 4GB MuVo2

I started out with a list of podcast feeds and put them in a text file, /etc/feeds. I noted that I wanted the ability to comment out any shows that I didn't have the time or space to listen to.

# /etc/feeds
# Hacker Public Radio http://www.hackerpublicradio.org/hpr_rss.php
# The Linux Link Tech Show #http://www.thelinuxlink.net/tllts/tllts.rss
# Mac Break Weekly http://leoville.tv/podcasts/mbw.xml
# The Metpod http://metropolis.co.jp/podcast/rss/
#Newsreal http://files.becomethemedia.net/rss/rantmedia/newsreal/24k/
# Off the Hook/Wall http://www.2600.com/rss.xml
# Security Now! #http://leoville.tv/podcasts/sn.xml
# TWiT http://leoville.tv/podcasts/twit.xml
Next, I wrote a Perl script that would iterate through that list, grab the RSS XML with LWP, parse it with a regex for the enclosure tag, and then download each MP3 with wget. It downloaded the latest podcast from each feed, and I added the capability to download every MP3 from a feed by adding the 'all' tag after the URL. I used no clobber with wget to avoid extraneous bandwidth use.

#!/usr/bin/perl -w
# podgrab.pl -

use strict; use LWP::UserAgent;

# Get the podcast addresses from a file open my $feeds, '<', "/etc/feeds" or die ">>> Can't open feeds: $!";

# Read the podcast URLs and pass # them to the download function while (<$feeds>) { download($_) unless /^#|^\s+$/; }

# Begin download function sub download {

# Check for and set the all flag my $all; chomp(my $url = $_[0]); if ($url =~ s/\s+all$//) { $all = 1; } else { $all = 0; }

# Grab the content and check status my $browser = LWP::UserAgent->new(); my $cast = $browser->get($url); my $stat = $cast->status_line; print "$stat\n\n" unless $cast->is_success;

# Read in cast content my $content = $cast->content;

# Grab the latest or every enclosure, # if it doesn't/they don't exist while ($content =~ /<enclosure.+url="(.+\.mp3)/g) { system("wget -nc $1"); last unless $all == 1; }

# End download }
That was a good start, but I still had to automate syncing. So, I wrote a bash script that called podgrab and rsync to add new podcasts to the MuVo, and remove podcasts that I deleted from my computer. I used xmessage to signal success or failure (see Figure 2).

#!/bin/bash
# podload.sh -
# Local workstation LOCAL="$HOME/media/podcasts"
# Portable media player PRTBL="/media/MUVO^2"
if [ -d $PRTBL ]; then cd $LOCAL ./podgrab sleep 1 (rsync -av --delete $LOCAL/ $PRTBL/podcasts && \ xmessage -center "Podcasts synced!" &> /dev/null) || \ xmessage -center "Sync failed!" &> /dev/null else xmessage -center "$PRTBL not mounted!" &> /dev/null fi

Figure 2: xmessage

I could change the local and portable directories as needed, and remove xmessage altogether if I worked without a GUI. My problems were solved. No more surfing around to multiple sites for my audio fix, and no more dealing with two sets of shows. All thanks to Linux and Open Source.


Other Resources
Meizu M6 Mini Player
TWiT Netcast Network