Exploring ADB Shell Commands#

Muhammed Abdullah

June 01, 2025

1 min read

Tried out ADB commands to explore and interact with my old Android device. Part of an ongoing deep-dive—looking into how apps behave, triggering intents, and inspecting packages.

I’m exploring lower-level Android internals with an eye toward writing applications in C and possibly doing AArch64 cross-compilation in the future.

I’ve previously written a few Android applications in Java during my college days—those notes can be found here.

ABD Basic Commands#

List the devices#

$ adb devices

Hang the system#

$ adb shell
RMX1807:/ $ am hang

Activity manager (`am`)#

See ADB IntentSpec for options.

Option	Description
`-a`	Action (e.g., `android.intent.action.VIEW`)
`-d`	Data URI (e.g., `-d http://example.com`)
`-t`	MIME type (e.g., `-t text/plain`)
`-c`	Category (e.g., `android.intent.category.LAUNCHER`)
`-n`	Component name (pkg/.Activity)
`-e`	Add string extra (`-e key value`)
`--ez`	Add boolean extra (`--ez key true`)
`--esn`	Add null extra
`--activity-clear-top`	Clears existing activity on top
`--activity-single-top`	Reuses existing instance if already on top

1. Open an Intent#

$ adb shell
RMX1807:/ $ am start -n com.intsig.camscanner/.CaptureActivity

RMX1807:/ $ am start -a android.intent.action.VIEW

2. Open Camera#

$ adb shell
RMX1807:/ $ am start -a android.media.action.IMAGE_CAPTURE

3. Open the app color reflexer #

RMX1807:/ $ am start -n com.colorreflexer/.MainActivity

4. Starting any other app like Cam Scanner#

Scan the activities:

RMX1807:/ $ dumpsys package com.intsig.camscanner | grep -i activity

Result#

Activity Resolver Table:
        ...
        99d05e7 com.intsig.camscanner/.MainMenuActivity filter 5e46134
        ...
        89d36d7 com.intsig.camscanner/.openapi.OCROpenApiActivity filter 70cc191
        9442cce com.intsig.camscanner/.Scan2PDFActivity filter 4fc7f64
        82f0d01 com.intsig.camscanner/.DocumentActivity filter 6005ca0
        529f832 com.intsig.camscanner/.ImageScannerActivity filter efa541e
        ...

Open camera scanning:

RMX1807:/ $ am start -n com.intsig.camscanner/.CaptureActivity

Open main menu:

RMX1807:/ $ am start -n com.intsig.camscanner/.MainMenuActivity

Result#

Starting: Intent { cmp=com.intsig.camscanner/.MainMenuActivity }

5. Starting Chrome#

RMX1807:/ $ am start -n com.android.chrome/com.google.android.apps.chrome.Main

Starting chrome with a URL:

RMX1807:/ $ am start -a android.intent.action.VIEW -d "http://example.com" -n com.android.chrome/com.google.android.apps.chrome.Main

Taking a screenshot#

RMX1807:/ $ screencap /sdcard/screen.png

And the screenshot is located in Phone/screen.png.

Open a Camera and click a picture#

RMX1807:/ $ am start -a android.media.action.IMAGE_CAPTURE

This opens the camera, but doesn’t trigger the capture. To simulate a tap:

RMX1807:/ $ wm size
Physical size: 1080x2340
RMX1807:/ $ input tap 540 512