patogglesh

#!/bin/bash
# paswitch 2011-02-02 by Ng Oon-Ee <ngoonee.talk@gmail.com>

# array of sound cards
cards=($(pacmd list-sinks | sed 's|*||' | awk '$1 == "index:" {print $2}'))

totalsc=${#cards[@]}
if [ $totalsc -le 1 ]; then # Check whether there are actually multiple cards available
  notify-send -u critical -t 5000 "Nothing to switch, system only has one sound card."
  exit
fi

# $scindex: The Pulseaudio index of the current default sound card
scindex=$(pacmd list-sinks | awk '$1 == "*" && $2 == "index:" {print $3}')
PICKNEXTCARD=1 # Is true when the previous card is default
while [ ${#cards[@]} -gt 0 ]
do
	for i in ${!cards[@]}; do
	  CARD=${cards[$i]}
	  if [ $PICKNEXTCARD = 1 ]; then
	# $nextsc: The pulseaudio index of the next sound card (to be switched to)
	    nextsc=$CARD
	    PICKNEXTCARD=0
	  fi
	  if [ $CARD = $scindex ]; then # Choose the next card as default
	    PICKNEXTCARD=1
	  fi
	done

	pacmd set-default-sink $nextsc # switch default sound card to next

	# ensure that switch was successful, and try again if not
	currsc=$(pacmd list-sinks | awk '$1 == "*" && $2 == "index:" {print $3}')
	if [ $currsc = $scindex ]; then
		unset cards[$i]
	else
		break
	fi
done

# $inputs: A list of currently playing inputs
inputs=$(pacmd list-sink-inputs | awk '$1 == "index:" {print $2}')
for INPUT in $inputs; do # Move all current inputs to the new default sound card
  pacmd move-sink-input $INPUT $nextsc
done

# $nextscdec: The device.description of the new default sound card
# NOTE: This is the most likely thing to break in future, the awk lines may need playing around with
#nextscdesc=$(pacmd list-sinks | awk '$1 == "device.description" {print substr($0,5+length($1 $2))}' \
#                         | sed 's|"||g' | awk -F"," 'NR==v1{print$0}' v1=$((nextind+1)))

#notify-send "Default sound-card changed to $nextscdesc"
#dbus-send --session --type=method_call --reply-timeout=10000 \
#  --dest=org.freedesktop.Notifications /org/freedesktop/Notifications \
#  org.freedesktop.Notifications.Notify  string:"paswitch"  uint32:1 \
#  string:$icon_name  string:"Default sound card is now"  string:"$nextscdesc" \
#  array:string:"" dict:string:string:"",""  int32:3000

# Below text was from original author and remains unaltered
# CC BY - creative commons
# Thanks God for help :) and guys lhunath, geirha, Tramp and others from irc #bash on freenode.net