android

name	android
description	Use when working with Android devices via ADB - connecting devices, running shell commands, installing apps, debugging, taking screenshots, UI automation, viewing logs, analyzing crashes, or exploring system internals. Triggers on "adb", "logcat", "install apk", "debug android", "android device", "shell command", "screenshot", "dumpsys", "crash", "ANR".

Android Device Mastery

This skill covers everything about interacting with Android devices via ADB and shell commands.

Device Connection

Check Connected Devices

adb devices -l

Output shows serial, status, and device info. Common statuses:

• device - Connected and authorized
• unauthorized - Accept USB debugging prompt on device
• offline - Connection issues, try adb kill-server && adb start-server

Wireless Debugging

Android 11+ (Recommended):

1. Enable Wireless debugging in Developer Options
2. Tap "Pair device with pairing code"
3. Run: adb pair <ip>:<pairing_port> and enter the code
4. Then: adb connect <ip>:<connection_port>

Legacy (requires USB first):

adb tcpip 5555
adb connect <device_ip>:5555

Multiple Devices

Always specify device with -s:

adb -s <serial> shell
adb -s emulator-5554 install app.apk

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Shell Commands

Interactive Shell

adb shell                    # Enter shell
adb shell <command>          # Run single command
adb shell "cmd1 && cmd2"     # Chain commands

Essential Commands

# Device info
getprop ro.product.model              # Device model
getprop ro.build.version.release      # Android version
getprop ro.build.version.sdk          # SDK level

# File operations
ls -la /sdcard/
cat /path/to/file
cp /source /dest
rm /path/to/file

# Process info
ps -A | grep <name>
pidof <package_name>
top -n 1 -m 10

Safe Output Limiting

For commands with potentially large output:

adb shell "logcat -d | head -500"
adb shell "dumpsys activity | head -200"

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App Management

Install/Uninstall

adb install app.apk                   # Basic install
adb install -r app.apk                # Replace existing
adb install -g app.apk                # Grant all permissions
adb install -r -g app.apk             # Both

adb uninstall com.example.app         # Full uninstall
adb uninstall -k com.example.app      # Keep data

Start/Stop Apps

# Start main activity
adb shell monkey -p com.example.app -c android.intent.category.LAUNCHER 1

# Start specific activity
adb shell am start -n com.example.app/.MainActivity

# Start with intent extras
adb shell am start -n com.example.app/.Activity \
    -a android.intent.action.VIEW \
    -d "myapp://page/123" \
    --es "key" "value"

# Force stop
adb shell am force-stop com.example.app

# Clear app data
adb shell pm clear com.example.app

List Packages

adb shell pm list packages              # All packages
adb shell pm list packages -3           # Third-party only
adb shell pm list packages | grep term  # Filter

adb shell pm path com.example.app       # APK location
adb shell dumpsys package com.example.app  # Full package info

Permissions

adb shell pm grant com.example.app android.permission.CAMERA
adb shell pm revoke com.example.app android.permission.CAMERA
adb shell dumpsys package com.example.app | grep permission

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File Operations

Push/Pull Files

adb push local_file.txt /sdcard/
adb pull /sdcard/remote_file.txt ./

# Recursive
adb push local_dir/ /sdcard/target/
adb pull /sdcard/dir/ ./local/

Access App Data (Debuggable Apps)

adb shell run-as com.example.app ls files/
adb shell run-as com.example.app cat shared_prefs/prefs.xml
adb shell run-as com.example.app sqlite3 databases/app.db ".tables"

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UI Automation

Input Commands

# Tap at coordinates
adb shell input tap 500 800

# Swipe (x1 y1 x2 y2 [duration_ms])
adb shell input swipe 500 1500 500 500 300

# Text input (needs focused field)
adb shell input text "hello"

# Key events
adb shell input keyevent KEYCODE_HOME      # Home
adb shell input keyevent KEYCODE_BACK      # Back
adb shell input keyevent KEYCODE_ENTER     # Enter
adb shell input keyevent KEYCODE_POWER     # Power
adb shell input keyevent KEYCODE_VOLUME_UP # Volume up

Common Keycodes

Code	Key	Code	Key
3	HOME	4	BACK
24	VOL_UP	25	VOL_DOWN
26	POWER	66	ENTER
67	DEL	82	MENU

Screenshots & Recording

# Screenshot
adb shell screencap -p /sdcard/screen.png
adb pull /sdcard/screen.png

# One-liner (binary-safe)
adb exec-out screencap -p > screen.png

# Screen recording (max 3 min)
adb shell screenrecord /sdcard/video.mp4
adb shell screenrecord --time-limit 10 /sdcard/video.mp4

UI Hierarchy

adb shell uiautomator dump /sdcard/ui.xml
adb pull /sdcard/ui.xml

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Debugging & Logs

Logcat Essentials

# Dump and exit
adb logcat -d

# Last N lines
adb logcat -t 100

# Filter by tag:priority
adb logcat ActivityManager:I *:S

# Filter by package (get PID first)
adb logcat --pid=$(adb shell pidof -s com.example.app)

# Crash buffer
adb logcat -b crash

Priority levels: V(erbose), D(ebug), I(nfo), W(arn), E(rror), F(atal), S(ilent)

Common Debug Patterns

# Find crashes
adb logcat *:E | grep -E "(Exception|Error|FATAL)"

# Activity lifecycle
adb logcat ActivityManager:I ActivityTaskManager:I *:S

# Memory issues
adb logcat art:D dalvikvm:D *:S | grep -i "gc"

Memory Analysis

adb shell dumpsys meminfo com.example.app

Key metrics:

• PSS: Proportional memory use (compare apps with this)
• Private Dirty: Memory exclusive to process
• Heap: Java/Native heap usage

Crash Analysis

# ANR traces
adb shell cat /data/anr/traces.txt

# Tombstones (native crashes, needs root)
adb shell ls /data/tombstones/

# Recent crashes via logcat
adb logcat -b crash -d

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System Inspection

dumpsys Services

adb shell dumpsys -l                    # List all services

# Common services
adb shell dumpsys activity              # Activities, processes
adb shell dumpsys package <pkg>         # Package details
adb shell dumpsys battery               # Battery status
adb shell dumpsys meminfo               # System memory
adb shell dumpsys cpuinfo               # CPU usage
adb shell dumpsys window displays       # Display info
adb shell dumpsys connectivity          # Network state

System Properties

adb shell getprop                       # All properties
adb shell getprop | grep <filter>       # Filter properties

# Useful properties
getprop ro.product.model                # Model
getprop ro.build.fingerprint            # Build fingerprint
getprop ro.serialno                     # Serial number
getprop sys.boot_completed              # Boot status (1 = done)

Settings

# Namespaces: system, secure, global
adb shell settings get global airplane_mode_on
adb shell settings put system screen_brightness 128
adb shell settings list global

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Reboot Commands

adb reboot                   # Normal reboot
adb reboot recovery          # Recovery mode
adb reboot bootloader        # Fastboot mode
adb reboot sideload          # Sideload mode
adb reboot-bootloader        # Alias for bootloader

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Troubleshooting

Device not found:

adb kill-server && adb start-server

Unauthorized:

• Check USB debugging is enabled
• Revoke USB debugging authorizations in Developer Options, reconnect

Multiple devices error:

• Use -s <serial> to specify device

Command not found (on device):

• Some commands require root or are version-specific
• Try /system/bin/<cmd> or check if command exists

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Quick Reference

Task	Command
List devices	adb devices -l
Install app	adb install -r -g app.apk
Start app	adb shell monkey -p pkg -c android.intent.category.LAUNCHER 1
Stop app	adb shell am force-stop pkg
Screenshot	adb exec-out screencap -p > screen.png
Logs	adb logcat -d -t 100
Shell	adb shell
Push file	adb push local /sdcard/
Pull file	adb pull /sdcard/file ./
Tap	adb shell input tap X Y
Back	adb shell input keyevent 4
Home	adb shell input keyevent 3

For deep dives into specific topics, see references/deep-dive.md.