Introduction

The Android Debugger (ADB) offers surprisingly extensive access to the innards of an Android phone.

The adb command makes it easy to, for instance, fetch all of your recent photographs and movie recordings off the phone, and copy podcasts onto the phone.

To jump inside an Android phone and access the command line interface, you will need:

• An Android phone that you have put in Developer Mode.
• A USB cable.
• A computer.

Once you have run your OS's terminal program, there are two ways to ssh into the phone:

If the phone is running a consumer grade (production) version of Android:

 adb shell

If it is running a development build of the OS, you can ssh as root:

 adb root

Phone characteristics

Get make and model

 getprop ro.product.brand
 getprop ro.product.model

System-on-Chip (SoC) characteristics

Get processor family

 cat /sys/devices/soc0/family

Get CPU chip name

 getprop ro.hardware.chipname
 getprop ro.hardware

Get CPU manufacturer

 cat /sys/devices/soc0/vendor

For example, Qualcomm.

Get CPU family

 cat /sys/devices/soc0/family

For example, Snapdragon.

Determine GPU name

 dumpsys | grep GLES:

Get the maximum core frequencies of the CPU

 cd /sys/devices/system/cpu
 cat cpu*/cpufreq/cpuinfo_max_freq

Get current core frequencies of the CPU

 cd /sys/devices/system/cpu
 cat cpu*/cpufreq/scaling_cur_freq

Memory and storage

Get RAM available to apps

 free -h
 grep MemTotal /proc/meminfo

Get flash storage information

 df -h

Display

Show display characteristics

Size:

 wm size

Frames per second (fps) and dots per inch (DPI):

 dumpsys display | grep DeviceInfo

Font size

This is a useful feature if you have trouble reading tiny text.

 settings put system font_scale 1.25

Screenshot

 screencap /sdcard/screenshot.png
 -or
 input keyevent 120

Screen recording

 screenrecord /sdcard/capture.mp4

Options:

• --time-limit (seconds)
• --rotate
• --bit-rate (Mb/sec)

Note! You may find on some devices that screenrecord is broken. If that is the case with your device, you can still record the screen by swiping down twice from the top of the display, from where you can run Android's built-in recorder GUI.

Screen mirroring to your computer

This is possible with screenrecord and mplayer.

adb exec-out screenrecord --bit-rate=16m --output-format=h264 - | mplayer -framedrop -cache 512 -demuxer h264es -fps 6000 -

Networks

Determine phone carrier

 getprop gsm.operator.alpha
 getprop gsm.sim.operator.alpha

Display current network connections 1

 netstat -e | grep -e tcp -e udp

Display current network connections 2

 ss -p -t -4 -6 -u

Turn cellular data on/off

 svc data enable
 svc data disable

Send an SMS

am start -a android.intent.action.SENDTO -d sms:+15551212 --es sms_body Test --ez exit_on_sent false

Turn the Wifi on/off

 svc wifi enable
 svc wifi disable

Show Wifi IP address

 ifconfig wlan0

List Wifi networks that phone has connected to

 dumpsys | grep hasEverConnected=1 | grep ssid=

Show Wifi hotspot name

 dumpsys | grep SemSoftApConfiguration

Get the Bluetooth MAC address

 settings get secure bluetooth_address

Turn the Bluetooth on/off

 svc bluetooth enable
 svc bluetooth disable

Get/set the phone's Wifi name

 settings get global device_name
 settings put global device_name PinePhone2

Turn NFC data on/off

 svc nfc enable
 svc nfc disable

Camera

The sensors' names are typically in the dumpsys output and are encoded as decimal ASCII values.

1. Adb shell to the phone and type cd /sdcard; dumpsys media.camera > myfile.txt
2. Copy that file back to your computer (adb pull /sdcard/myfile.txt) and open it.
3. Search in that file for samsung.android.sensor.info.sensorName and find one entry per sensor, plus maybe an extra one.

Because the sensor name is represented as ASCII decimal values, which you will need to convert it to ASCII e.g. with my converter utility.

Once converted, you may notice a sensor name that begins with IMX. That is a Sony sensor (and hopefully not a knock-off).

A sensor name that begins with S5K is a Samsung sensor.

Here are my phone's sensors:

• 83 53 75 71 87 49 80 = Samsung 64MP S5KGW1P
• 73 77 88 54 49 54 = Sony 32MP IMX616
• 83 53 75 51 76 54 = Samsung 13MP S5K3L6
• 71 67 53 48 51 53 = 5MP GC5035
• 71 67 53 48 51 53 95 77 65 67 82 79 = 5MP GC5035_MACRO

Apps

List all apps

 pm list packages

List third-party apps

 pm list packages -3

List running apps

 ps -fA | grep u0_ | sed 's/^.*:[0-9][0-9] //' | sort

Determine which core an app is running on

 ps -o pid,psr,time,comm -p $(pgrep -x programName)

Delete an app

Remove an app easily (in this case Webex) with this command:

 pm uninstall com.cisco.webex.meetings

If you see an error, you may need to add --user 0 after uninstall. Like so:

 pm uninstall --user 0 com.sec.android.app.safetyassurance
 pm uninstall --user 0 com.google.android.safetycenter.resources
 pm uninstall --user 0 com.samsung.safetyinformation

Clear an app's data

Clear out the data associated with an app (in this case Audible's book data) thus:

 pm clear com.audible.application

Remove Samsung's game bloatware

 pm uninstall --user 0 com.samsung.android.game.gos
 pm uninstall --user 0 com.samsung.android.game.gamehome
 pm uninstall --user 0 com.samsung.android.game.gametools

Disable Samsung Cloud

 pm uninstall --user 0 com.samsung.android.scloud

Remove other Samsung bloat

 pm uninstall --user 0 com.samsung.android.kidsinstaller
 pm uninstall --user 0 com.android.providers.partnerbookmarks
 pm uninstall --user 0 com.samsung.android.smartswitchassistant
 pm uninstall --user 0 android.autoinstalls.config.samsung

Remove Youtube Music

 pm uninstall --user 0 com.google.android.apps.youtube.music

Remove Google One

 pm uninstall --user 0 com.google.android.apps.subscriptions.red

Remove built-in Facebook apps

Some phone carriers stealthily include Facebook apps on low-end phones. These may run automatically in the background but not appear in the Apps drawer. This is a security concern.

 pm uninstall --user 0 com.facebook.services
 pm uninstall --user 0 com.facebook.system
 pm uninstall --user 0 com.facebook.appmanager
 pm uninstall --user 0 com.facebook.katana

Even after all Facebook apps are remove, you may still observe (by using the ss command) periodic connections to Facebook servers such as 2a03:2880:f034:112:face:b00c:0:2.

Disable built-in Microsoft apps

 pm suspend com.microsoft.appmanager
 pm suspend com.microsoft.skydrive

Set up a Linux-like command-line environment

While you can log in via ADB, you can't use a compiler, Python, or other useful packages.

To set up a proper command-line environment with a compiler and editor, install Termux.

If you want to use it properly, you should connect a keyboard via the USB-C port.

Home screen

Prevent swipe-right from Home into nauseating news screen

In Android 11, swiping right from the first home screen takes you to a clickbait news page.

This was briefly disableable via ADB but now doing so requires using Android's menus.

To disable it, swipe into the news screen, tap the menu button, tap Settings and disable personalized news from there.

Samsung Bixby

Remove Bixby

 pm uninstall --user 0 com.samsung.android.app.spage
 pm uninstall --user 0 com.samsung.android.bixby.service

On-screen keyboards

Remove Samsung keyboard

 pm uninstall -k --user -0 com.sec.android.inputmethod

Mounting the file system from Linux

Using Media Transfer Protocol (MTP)

This is a very useful feature for directly accessing media files. It might be finnicky about other types of files. If you have large videos or large numbers of photos on your Android device, this will let you skip the process of transferring those to your Linux computer just to find out some were not worth keeping.

Install the software:

 sudo apt update
 sudo apt install mtp-tools jmtpfs gvfs-backends gvfs-fuse

Mount /sdcard:

 mkdir ~/Android
 jmtpfs ~/Android

Unmount it:

 fusermount -u ~/Android

To detect MTP file systems, use this:

 mtp-detect

Using ADBFS

My distro (Debian) doesn't have this program, but it is written in Go and can be found on Github.

 sudo apt install adbfs
 mkdir ~/Android
 adbfs ~/Android

Vibrator

Vibrate for a specified number of milliseconds. This works with Android 9. It may not work in Android 11 and later.

 cmd vibrator vibrate 100

To find out what the vibrator can do:

 cmd vibrator capabilities

On newer Android versions, this will list vibrator devices:

 cmd vibrator_manager list

Simulating input events

Power

 * Press power key = input keyevent 26
 * Make device sleep = input keyevent KEYCODE_POWER
 * Make device wake up = input keyevent KEYCODE_WAKEUP

Go to Home screen

 input keyevent 3

Go back

 input keyevent 4

Camera app

 * Launch the app: input keyevent 27
 * Take a photo: input keyevent 108 (this is the Start button)
 * Switch to single-take mode: input keyevent 105
 * Switch to video capture mode: input keyevent 104

Go to app switcher

 input keyevent 187

Launch contacts app

 input keyevent 207

Launch calendar app

 input keyevent 208

Launch music app

 input keyevent 209

Launch phone app

 input keyevent 5 (launch phone app)
 input keyevent 6 (hang up)
 input keyevent 79 (''headset hook'' = hang up call, stop media playback)
 input keyevent 164 (mute output)
 input keyevent 91 (mute microphone)

Launch web browser

 input keyevent 64

Launch mail application

 input keyevent 65

Brightness

 * Increase = input keyevent 221
 * Decrease = input keyevent 220

Sound volume

 * Increase = input keyevent 24
 * Decrease = input keyevent 25
 * Mute = input keyevent 164

Clipboard

 * Cut = input keyevent 277
 * Copy = input keyevent 278
 * Paste = input keyevent 279

Google search

 input keyevent 84

Menus

 input keyevent 101 (show or hide menu)

Tabs

• Close current tab = input keyevent 97
• Next tab = input keyevent 103
• Previous tab = input keyevent 102

Cursor

 input keyevent 19 (move cursor up)
 input keyevent 20 (move cursor down)

Scrolling

 input keyevent 92 (page up)
 input keyevent 93 (page down)
 input keyevent 122 (home)
 input keyevent 123 (end)

Media players

To start playing the current song or audio book:

 media dispatch play
 -or-
 input keyevent 126

To stop playing the current song or audio book:

 media dispatch stop
 -or-
 input keyevent 127

To launch the media player and play a video:

 am start -a android.intent.action.VIEW -d file:///sdcard/video.mkv -t video/mkv

To launch the media player and play a sound:

 am start -a android.intent.action.VIEW -d file:///sdcard/sound.ogg -t audio/ogg

Power

Reboot

 reboot
 svc power reboot

Power down

 svc power shutdown

Backup and restore

The backup mechanism will NOT save your contacts. If possible store those on your SIM card.

 adb backup -all -apk -nosystem -f mybackup.ab

Restore (I have not verified that this works):

 adb restore mybackup.ab

Factory restore

Do this at your own risk!

Don't forgot to:

• Write down your PIN and Google account details.
• Perform a backup.

The PIN will be needed to set up Android.

1. Turn off the device.
2. Press Volume Up and Power at the same time and hold them.
3. When the company logo appears, release only the power button.
4. When the Android logo appears, release the volume button.
5. This should give you a menu that will let you wipe data and factory reset or similar.

From the command line:

 adb reboot recovery

Access service mode

 *#0011#

Scam block

 #662# to enable Scam Block
 #664# to enable Scam ID
 #632# to disable both.

Links

• T-Mobile short codes