Add get_binary_from_pid function

Also add documentation for installing as daemon

README.md

@@ -10,8 +10,22 @@ I am open to supporting other window systems if there is sufficient interest.
 
 Download the script (via `curl` or `wget`) and `chmod +x pa-xtouch-control` to make it executable. Then run it with `./pa-xtouch-control` and test your Behringer X-Touch Mini to make sure everything is working.
 
-# Installation as a daemon
- TODO
+# Installation as a daemon (`systemd`)
+1. Download the `pa_xtouch_control.sh` and `pa_xtouch_control.service` files. 
+2. Make the `pa_xtouch_control.sh` script executable with `chmod +x pa_xtouch_control.sh`.
+3. Place `pa_xtouch_control.sh` into `/usr/bin/` with `mv pa_xtouch_control.sh /usr/bin/`.
+4. Place `pa_xtouch_control.service` into `~/.config/systemd/user/` (just 'user', not your username) with `mv pa_xtouch_control.service ~/.config/systemd/user/`
+5. Create this directory if it does not already exist `mkdir -p ~/.config/systemd/user/`.
+6. Reload systemd with `systemctl --user daemon-reload`.
+7. Enable autostart of the systemd service with `systemctl --user enable pa_xtouch_control.service`.
+8. Start the service with `systemctl --user start pa_xtouch_control.service`.
+
+You can do all of these steps with:
+
+```bash
+
+```
+
  
 # Modifying the script
 

pa_xtouch_control.service

@@ -0,0 +1,8 @@
+[Unit]
+Description=PulseAudio X-Touch control daemon
+
+[Service]
+ExecStart=/usr/bin/pa_xtouch_control.sh
+
+[Install]
+WantedBy=default.target

pa_xtouch_control.sh

@@ -197,9 +197,17 @@ get_stream_index_from_pid(){
 	done
 }
 
-get_pid_from_binary(){
-	# todo
-	echo "Not yet implemented"
+get_binary_from_pid(){
+	output="$(paste -d"\t" \
+		<(printf '%s' "$output" | grep 'application.process.id' | cut -d'"' -f 2) \
+		<(printf '%s' "$output" | grep 'application.process.binary' | cut -d'"' -f 2))"
+
+	echo "$output" | while read line ; do
+		pid=$(echo "$line" | cut -f1)
+		if [[ "$pid" == "$1" ]]; then
+			echo "$line" | cut -f2
+		fi
+	done
 }
 
 bind_application() {