android

What this skill does

# Android Device Mastery

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

## Device Connection

### Check Connected Devices

```bash
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):**

```bash
adb tcpip 5555
adb connect <device_ip>:5555
```

### Multiple Devices

Always specify device with `-s`:

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

---

## Shell Commands

### Interactive Shell

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

### Essential Commands

```bash
# 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:

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

---

## App Management

### Install/Uninstall

```bash
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

```bash
# 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

```bash
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

```bash
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
```

---

## File Operations

### Push/Pull Files

```bash
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)

```bash
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"
```

---

## UI Automation

### Input Commands

```bash
# 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

```bash
# 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

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

---

## Debugging & Logs

### Logcat Essentials

```bash
# 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

```bash
# 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

```bash
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

```bash
# 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
```

---

## System Inspection

### dumpsys Services

```bash
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

```bash
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

```bash
# 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
```

---

## Reboot Commands

```bash
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
```

---

## Troubleshooting

**Device not found:**

```bash
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

---

## 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` |
|