Script to kill an Android emulator which requires authentication

kill-emulator.exp

#!/usr/bin/expect

##############################################################
#
# KILL-EMULATOR
#
# Kills an Android emulator which requires authentication.
# It works by opening a telnet session and authenticates, before issuing the
# kill command.
#
# Usage: `expect -f kill-emulator.exp <port>`
# where <port> is optional (defaults to 5554)
#
# Since SDK Tools 25.1.6, the Android emulator has required authentication
# before any commands can be run on it. This breaks commands such as
# `adb emu kill`.
#
# References:
# - https://developer.android.com/studio/run/emulator-commandline.html#console-session
# - https://code.google.com/p/android/issues/detail?id=21021#
#
##############################################################

set timeout 10

# Parse params.
# Port is optional, and defaults to 5554
proc parseArgv {{port "5554"}} {
    variable ::PORT $port
}
parseArgv {*}$argv

# Read auth token from file
set TOKEN [read [open "$::env(HOME)/.emulator_console_auth_token" r]]

send_user "Killing emulator on port $PORT with auth token $TOKEN\n"

# Start telnet session, and issue the commands.
spawn telnet localhost $PORT
expect "OK"
send "auth $TOKEN\r"
send "kill\r"

Thank you very very much! I had to insert additional
expect "OK"
like this:

# Start telnet session, and issue the commands.
spawn telnet localhost $PORT
expect "OK"
send "auth $TOKEN\r"
expect "OK"
send "kill\r"
expect "OK"

to get it working.

great work! this fixed my CI... saved me the time having to fix it myself, cheers!

It can also be done with a bash function:

function stopAvd() {
    nc localhost 5554 << _EOF > /dev/null 2>&1
auth `cat  ~/.emulator_console_auth_token`
kill
_EOF
}

If you don't need the auth token, like in a CI runner, then you can do it very simply without auth:

cp /dev/null ~/.emulator_console_auth_token
echo kill | nc -w 120 localhost 5554
rm -f ~/.emulator_console_auth_token