1. Capture screenshot through shell command.
# screencap -p /sdcard/screen.png
2. am [Activity Manager]
==> Active default browser and go to "google" directly.
# am start -a android.intent.action.VIEW -d http://www.google.com
==> Active Gallery3d to play movie file.
# am start -n com.android.gallery3d/.app.MovieActivity -d file:////sdcard/Movies//movie.ts
==> Open a JPEG file.
# am start -a android.intent.action.VIEW -d file:////data/worktmp//taiwan.jpg -t image/jpeg
==> Play a MP3 file.
# am start -a android.intent.action.VIEW -d file:///data/worktmp/1kTone.mp3 -t audio/mp3
3. Shutdown
# reboot -p
-p: power off
# busybox poweroff
# am start -a android.intent.action.ACTION_REQUEST_SHUTDOWN --ez KEY_CONFIRM true --activity-clear-task
4. Reset to factory default.
# am broadcast -a android.intent.action.MASTER_CLEAR
