g.mapset changes the current working MAPSET, LOCATION, or GISDBASE.
This is a fairly radical maneuver to run mid-session, take care when running
the GUI at the same time.
NOTES
The shell continues to use the history for the old mapset. To change this
you can switch the history to the new settings by commands:
history -w
history -r /"$GISDBASE/$LOCATION/$MAPSET"/.bash_history
HISTFILE=/"$GISDBASE/$LOCATION/$MAPSET"/.bash_history