Switching audio bluetooth profiles with a script

I wanted to be able to switch between “listening to music” and “using the headphone’s microphone” easily. i3blocks allows me to write scripts emit a status line, and can accept “clicks” in the form of environment variables to respond. I wrote one that, using the pulseaudio CLI:

1. Checks how many audio bluetooth devices are connected
2. If there are none / more than one, prints that and exits
3. If there was a mouse left click, choose the “other profile” and apply it
4. Print the current profile

It’s pretty short and sweet, so I thought I’d share it

The Script

#!/bin/bash
set -Eeuo pipefail

INDEXES="$(pacmd list-cards | (grep 'name: <bluez_card.' -B2 || true) | perl -ne 'print $1,$/ if /index: (\d+)/')"
INDEX_COUNT="$(echo "$INDEXES" | wc -l)"
if [[ "$INDEX_COUNT" > 1 ]]; then
  echo "MULTIPLE"
  exit
elif [[ "$INDEX_COUNT" < 1 || "$INDEXES" == "" ]]; then
  echo "NONE"
  exit
fi

# Only one
INDEX="$INDEXES"

get_profile() {
  pacmd list-cards | grep "index: ${INDEX}" -A22 | perl -ne 'print $1,$/ if /active profile: <(.+)>/'
}

# left click
if [[ "${BLOCK_BUTTON:-0}" == 1 ]]; then
  if [[ "$(get_profile)" == "a2dp_sink" ]]; then
    NEXT_PROFILE="handsfree_head_unit"
  else
    NEXT_PROFILE="a2dp_sink"
  fi
  pacmd set-card-profile "$INDEX" "$NEXT_PROFILE"
fi

get_profile