Script to generate a Podcasts/Overcast-compatible RSS feed for audio files on your own web server

make-audio-feed.sh

#!/usr/bin/env bash

# Generates an RSS feed for a list of audio files, for consumption by Overcast
# and other podcast players.
#
# Usage:   make-audio-feed TITLE BASE_URL FILE...
# Example: (cd directory && make-audio-feed 'My Audio Files' 'https://your.server/directory/' * > .feed.rss)

set -eu -o pipefail

# https://gist.github.com/cdown/1163649#gistcomment-2157284
urlencode() {
    local LANG=C i c e=''
    for ((i=0;i<${#1};i++)); do
        c=${1:$i:1}
        [[ "$c" =~ [a-zA-Z0-9\.\~\_\-] ]] || printf -v c '%%%02X' "'$c"
        e+="$c"
    done
    echo "$e"
}

entity-escape() {
    sed 's/&/\&amp;/g; s/</\&lt;/g; s/>/\&gt;/g; s/"/\&quot;/g; s/'"'"'/\&#39;/g'
}

title=$1
shift

echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
<rss xmlns:itunes=\"http://www.itunes.com/dtds/podcast-1.0.dtd\" version=\"2.0\">
    <channel>
        <title>$title</title>
        <description>$title</description>
        <link></link>
"

base_url=$1
shift

for f in "$@"; do
    # Use the file's mtime for the pubDate
    pubTimeEpoch=$(stat -c %Y -- "$f")
    pubDate=$(date --date="@$pubTimeEpoch" '+%a, %d %b %Y %H:%M:%S %z')
    echo "\
        <item>
            <title>$(echo -n $f | entity-escape)</title>
            <guid>$(echo -n $f | entity-escape)</guid>
            <enclosure url=\"${base_url}$(urlencode "$f" | entity-escape)\" type=\"audio/mp3\" />
            <pubDate>$pubDate</pubDate>
        </item>"
done

echo "\
    </channel>
</rss>
"