The Dumpsys command displays information about all applications in your phone and also gives you the status of your phone.
Direct execution adb shell dumpsys KEY Displays all of the following information.
Optional name of key Surfaceflinger, accessibility, account, activity, Alarm, appwidget, audio, backup, battery, Batteryinfo, Bluetooth, BLUETOOTH_A2DP, clipboard, connectivity, content, Cpuinfo, Device_policy, Devicestoragemonitor, Diskstats, Dropbox, entropy, hardware, hdmi, Input_method, Iphonesubinfo, isms, location, Media.audio_flinger, Media.audio_policy, Media.camera, Media.player, Meminfo, Mount, netstat, network_management, notification, package, permission, phone, power , search, sensor, Simphonebook, StatusBar, Telephony.registry, throttle, Uimode, usagestats, vibrator, wallpaper, WiFi, WI Ndow
Reference Links:
http://androiddeveloper.diandian.com/post/2014-01-28/40060888379
Android shell Command Dumpsys