You can dump system data to the screen by the command
shell dumpsys. The output shows lots of information, so you might redirect STDOUT to a text file.
% adb shell dumpsys > dump.txt
% less dump.txt
Currently running services:
The first section tells about Currently running services. If a service name is specified after
dumpsys, then the other sections are filtered out.
# Show only "battery"
% adb shell dumpsys battery
Current Battery Service state:
AC powered: true
USB powered: false
Wireless powered: false
Look up the
Activitiy Resolver Table section in the output of the command
shell dumpsys package.
% adb shell dumpsys package > package.txt
% less package.txt
Activity Resolver Table:
Full MIME Types:
41adb878 com.android.music/.MediaPlaybackActivity filter 41adb9e0