For battery percentages of 08 and 09 percent, the `-le` would fail with
an error ("value too great for base"), since the numbers with leading
zeros are treated as octal numbers when using double brackets.
The solution is to force base 10 for the numbers. More details here:
http://stackoverflow.com/a/24777667/1228454
If the user is currently in a valid sudo session (sudo currently does
not require a password), then the username part of the right prompt will use
a different color (orange). This gives an indication to the user that
sudo commands will not require a password at the moment. One example for
this might be that the user is reminded to run a `sudo -k` to terminate
the current sudo session before stepping away from the screen.
Bez Hermoso
Nils Winkler
jitakirin
Ignasi Fosch
Eduardo Bellido Bellido
Travis Swicegood