Asterisk voicemail notifications with MP3

#!/bin/bash
 
# mp3mail accepts a mail message via STDIN and converts an attached WAV file to MP3
# Based on a script by Nicolas Bernaerts (http://bernaerts.dyndns.org/linux/179-asterisk-voicemail-mp3)
# Rewritten to remove dependencies, reduce number of commands, and general cleanup by Michael Newton (mnewton@poptalk.ca)
 
# location of the lame binary
LAME=/usr/bin/lame
 
# Information for mp3 tags
MP3PUBLISHER=""
IMAGEPATH=/var/lib/asterisk/images/logo.png
 
# create a temporary directory and cd to it
TMPDIR=$(mktemp -d)
cd "$TMPDIR" || exit
 
# dump the stream to a temporary file
cat >> stream.org
 
# if we don't have lame, abort and send it normally
if [[ -z "$LAME" ]] || [[ ! -x "$LAME" ]]; then
	sendmail -t < stream.org
	rm -Rf "$TMPDIR"
	return 1
fi
 
# get the boundary
BOUNDARY=$(grep -Pom 1 '(?<=boundary=").+(?=")' stream.org)
 
# cut the file into parts
# stream.part - header before the boundary
# stream.part1 - header including the boundary and following lines
# stream.part2 - body of the message
# stream.part3 - attachment in base64 (WAV file)
# stream.part4 - footer of the message
awk "/$BOUNDARY/{i++}{print > \"stream.part\"i}" stream.org
 
# cut the attachment into parts at the first empty line
# stream.part3.head - header of attachment
# stream.part3.wav.base64 - wav file of attachment (encoded base64)
sed '/^$/,$d' stream.part3 > stream.part3.wav.head
echo >> stream.part3.wav.head
sed '1,/^$/d' stream.part3 > stream.part3.wav.base64
 
# convert the base64 file to a wav file
base64 -di stream.part3.wav.base64 > stream.part3.wav
 
# Get information for the ID3 tags from the email body and headers
# The grep patterns depend on the content of your emails; the below patterns assume the default message
# Use like so: (?<=THE STUFF BEFORE)THE MATCH(?=THE STUFF AFTER)
MP3TEXT=$(cat stream.part2 stream.part1 stream.part)
# message number
MP3NUM=$(echo "$MP3TEXT" |  grep -Pom 1 '(?<=message \(number )\d+(?= \))')
# CID name; expects '"The name" <1234567890>' but won't match 'an unknown caller'
MP3CIDNAME=$(echo "$MP3TEXT" |  grep -Pom 1 '(?<=from ").+(?=")')
# CID number
MP3CIDNUM=$(echo "$MP3TEXT" |  grep -Pom 1 '(?<=\<)\d+(?=\>)')
 
# add an image if specified above
if [[ -z "$IMAGEPATH" ]]; then MP3IMAGE=""; else MP3IMAGE="--ti $IMAGEPATH"; fi
 
# convert wav file to mp3 file and add tags
$LAME --preset standard \
	--tt "Message $MP3NUM" \
	--tn "$MP3NUM" \
	--ta "$MP3CIDNAME" \
	--tl "$MP3CIDNUM" \
	--tg Speech \
	"$MP3IMAGE" \
	--tv TPUB="$MP3PUBLISHER" \
	--id3v2-only \
	stream.part3.wav stream.part3.mp3
 
# generate the new mp3 attachment header
# change Type: audio/x-wav to Type: audio/mpeg
# change name="msg----.wav" to name="msg----.mp3"
sed -e 's/x-wav/mpeg/g' -e 's/\.wav/.mp3/g' stream.part3.wav.head > stream.part3.mp3.head
 
# convert mp3 to base64
base64 stream.part3.mp3 > stream.part3.mp3.base64
 
# put it together to make the email
cat stream.part \
	stream.part1 \
	stream.part2 \
	stream.part3.mp3.head \
	stream.part3.mp3.base64 \
	stream.part4 \
	> stream.new
 
# ensure line endings are CRLF (per RFC) and feed to sendmail
sed 's/\r*$/\r/' stream.new | sendmail -t
 
# remove all temporary files and temporary directory
rm -Rf "$TMPDIR"