[SOLVED] Control bluetoothctl with scripting?

Jason_25 · 10-09-2017, 02:10 PM

I am trying to interact with bluetoothctl through scripting. Such as shown in these threads:
https://stackoverflow.com/questions/...alent-commands
https://stackoverflow.com/questions/...er-interaction

Code:

bluetoothctl << EOF \n pair 54:46:6B:01:6C:CC \n EOF

result: > is displayed and nothing happens

Code:

echo -e 'pair 54:46:6B:01:6C:CC' | bluetoothctl

result: command is entered and bluetoothctl immediately quits without waiting for the pin prompt so it can be captured

Code:

bluetoothctl <<< 'pair 54:46:6B:01:6C:CC'

result: command is entered and bluetoothctl immediately quits without waiting for the pin prompt so it can be captured

What is the solution here?

edit: Fixed.

I tried to use:

Code:

hcitool cc <bdaddr>; hcitool auth <bdaddr>

This always failed.

I then tried to use screen which was similar to the second two problems above in that the bluetoothctl just quits immediately. I also spent some time needlessly trying to manipulate the file handlers for the process in /proc but ultimately that just writes to the screen not the program itself. Finally the answer was to use Tmux as so:

Code:

tmux new-session -d -s ServerFault 'sudo bluetoothctl -a |& tee /run/shm/BLUETOOTH_OUTPUT'

To send commands:

Code:

tmux send-keys -t ServerFault -l 'pair BT_MAC_OF_SLAVE_GOES_HERE'
tmux send-keys -t ServerFault Enter

To debug you can tmux attach-session -t ServerFault or cat /run/shm/BLUETOOTH_OUTPUT.

Notes: I had to remove all the tr and a through z stuff. Just by accident I stumbled upon the |& tee stuff. That is required because a normal redirect to file does not work and is blank. I chose /run/shm because at least on the Raspberry Pi that is where RAM files are stored. The word ServerFault can be anything you like. I think the newest version of Bluez may have a different, possibly better utility for doing this. As far as bluetoothctl itself goes it takes more to actually do anything than the examples here. It also takes way more to actually write a script that can handle Bluetooth connections through bluetoothctl but hopefully this gets you started on one or allows you to work up a simple solution.

References:
https://serverfault.com/questions/17...a-screen-sessi
https://www.reddit.com/r/tmux/commen...zh&sh=48426000

firstfire · 10-16-2017, 11:11 PM

Hi.

In bash you can use e.g. coproc to start and communicate with another process:

Code:

#!/bin/bash

coproc bluetoothctl
echo -e 'info 54:46:6B:01:6C:CC\nexit' >&${COPROC[1]}
output=$(cat <&${COPROC[0]})
echo $output

Here COPROC is a two-element array containing output/input file descriptors respectively. See the Coprocesses section of man bash for details.

pantiri · 05-03-2018, 06:44 AM

Hi,
seems that your answer cannot be working in a script, but only via command line
i faild to launch a script that executes coproc command

firstfire · 05-04-2018, 05:35 AM

Hi.

Welcome to LQ!

It works for me (in the sense that it is possible to interact with background process; it's up to you what exactly you'll do with bluetoothctl) so make sure that

1. You made the script executable (chmod +x script.sh)
2. Your version of bash supports coproc (help coproc; Coprocesses section in man bash)
3. bluetoothctl is actually installed and working.
4. bluetoothctl adds color codes and other control characters to output which may lead to strange results (e.g. it may appear that there are no output at all -- pipe to less or hd to see that it's there). To alleviate this one may use sed, for instance

Code:

$ /tmp/test.sh | sed 's/\x1B\[[0-9;]*[JKmsu]//g; s/\r/\n/g'
Waiting to connect to bluetoothd...
[bluetooth]#
[NEW] Controller C4:85:08:A0:67:51 alar [default] [bluetooth]#
[NEW] Device 1C:52:16:9A:DC:D5 QCY-QY19 [bluetooth]#
[NEW] Device 9C:DF:03:0E:C7:EC harman BT [bluetooth]#
[NEW] Device 00:0D:18:A1:50:2F MMC12 [bluetooth]# info 54:46:6B:01:6C:CC Device 54:46:6B:01:6C:CC not available [bluetooth]# exit [bluetooth]#
[DEL] Controller C4:85:08:A0:67:51 alar [default] [bluetooth]#

Waiting to connect to bluetoothd...

pantiri · 05-04-2018, 06:19 AM

Hello
Many thanks for your answer and help
actually it's working in command line, so i think coproc is supported and bluetoothctl is installed and working
When I launch it in command line, line by line it works
Then I create a simple script, I make it executable with others simple commands like echo.. I can see echo results
But when I check the process I see that coproc bluetoothctl has not been launched
and so I have help coproc showing this
i@pi3_portail:~/script_py$ help coproc
coproc: coproc [NAME] command [redirections]
Create a coprocess named NAME.

Execute COMMAND asynchronously, with the standard output and standard
input of the command connected via a pipe to file descriptors assigned
to indices 0 and 1 of an array variable NAME in the executing shell.
The default NAME is "COPROC".

Exit Status:
The coproc command returns an exit status of 0.

pantiri · 05-04-2018, 06:21 AM

So i thing, from your answer, the point 1, 2, 3 are OK
For the point 4.. not very clear for me sorry

mgerber · 07-28-2018, 06:03 AM

Hi.

I tried your script @firstfire.
It always tells me the agent is not registered.

Code:

~$ connect-bluetooth-speaker.sh 
Restarting bluetooth service.
[NEW] Device CC:D2:AC:A8:78:B7 MX Anywhere 2S [bluetooth]# connect AE:2D:22:00:35:A2 Attempting to connect to AE:2D:22:0[DEL] Controller 60:F6:77:45:DA:4D BlueZ 5.48 [default] No agent is registered

But if I launch bluetoothctl manually, the agent registers, and I can connect the device.
I tried adding "agent on\n" to the connect line, but to no avail.

Code:

echo -e 'connect AE:2D:22:00:35:A2\nexit' >&${COPROC[1]}

The output is then like this:

Code:

~$ connect-bluetooth-speaker.sh 
Restarting bluetooth service.
[NEW] Device AE:2D:22:00:35:A2 MS-10DMKII [bluetooth]# agent on Failed to register agent object [bluetooth]# connect AE:[DEL] Device 50:1A:A5:76:ED:F8 Jabra MOVE v2.5.0 [DEL] Device DD:B3:5F:80:79:3F HP Tilt Pen [DEL] Device C5:1B:74:09:FC:45 fenix 3 HR [DEL] Device CC:D2:AC:A8:78:B7 MX Anywhere 2S No agent is registered [DEL] Controller 60:F6:77:45:DA:4D BlueZ 5.48 [default]

My script looks like this.
I restart the bluetooth service because otherwise, after waking up from sleep, audio sink bluetooth connection fail.

Code:

echo Restarting bluetooth service.
sudo service bluetooth restart

coproc bluetoothctl
echo -e 'agent on\nconnect AE:2D:22:00:35:A2\nexit' >&${COPROC[1]}
output=$(cat <&${COPROC[0]})
echo $output

mgerber · 07-28-2018, 06:05 AM

Launching bluetoothctl manually has the following effect.

Code:

~$ bluetoothctl 
[NEW] Controller 60:F6:77:45:DA:4D spectre [default]
...
...
...
[NEW] Device AE:2D:22:00:35:A2 MS-10DMKII
Agent registered
[MX Anywhere 2S]# connect AE:2D:22:00:35:A2
Attempting to connect to AE:2D:22:00:35:A2
[CHG] Device AE:2D:22:00:35:A2 Connected: yes
Connection successful
[CHG] Device AE:2D:22:00:35:A2 ServicesResolved: yes
[MS-10DMKII]#

mgerber · 07-28-2018, 06:12 AM

Additionally, like pantiri, when I launch your commands manually (not in bash script), it works fine.

mgerber · 07-28-2018, 06:24 AM

And with your sed command, I get following output.

Code:

~$ connect-bluetooth-speaker.sh  | sed 's/\x1B\[[0-9;]*[JKmsu]//g; s/\r/\n/g'
Restarting bluetooth service.

Waiting to connect to bluetoothd...
[bluetooth]# 
[NEW] Controller 60:F6:77:45:DA:4D BlueZ 5.48 [default] [bluetooth]# 
[NEW] Device AE:2D:22:00:35:A2 MS-10DMKII [bluetooth]# 
...
[NEW] Device CC:D2:AC:A8:78:B7 MX Anywhere 2S [bluetooth]# agent on Failed to register agent object [bluetooth]# connect AE:2D:22:00:35:A2 Attempting to connect to AE:2D:22:00:35:A2 [bluetooth]# exit [bluetooth]# 
[DEL] Controller 60:F6:77:45:DA:4D BlueZ 5.48 [default] No agent is registered

mgerber · 07-30-2018, 12:43 AM

Solved it by using the following automation script:
https://gist.github.com/RamonGilaber...b302b4d9fb0055

Code:

set prompt "#"
set address AE:2D:22:00:35:A2
# set address [lindex $argv 0]

send_user "\nRestarting bluetooth service.\r"
spawn sudo service bluetooth restart

send_user "\nConnecting to MS-10DMKII.\r"
spawn bluetoothctl
expect -re $prompt
expect "Agent registered"
send "connect $address\r"
expect "Connection successful"
send "quit\r"
expect eof

nvergontbij · 01-08-2020, 06:28 AM

Code:

#!/usr/bin/zsh

coproc bluetoothctl
echo -e 'agent on\nconnect F0:13:C3:4B:84:E9\nexit' >&p
output=$(cat <&p)
echo $output

just my 2 cents.