1) Does any file in /usr/bin/ have a filename that starts with an 'a'?

2) Does any file in /usr/bin/ have a filename that starts with an 'a' and there is a 'b' somewhere later?

3) How many filenames in /usr/bin have exactly four letters?

4) How many filenames in /usr/bin start with a capital letter?

5) How many users on on the system?
Hint:  count the lines of /etc/passwd

6) Print a sorted list of user names.
Hint:  there is a sort command

7) How many users have /bin/bash as a shell?
Hint:  grep searches, wc counts, use a pipe.

8) Which of these files are world readable:  /etc/passwd, /etc/group, /etc/shadow, /etc/gshadow?

9) Does any user have any jpg files?

10) Write me a command that makes me a text file with every human user's name in it.

11) Write me a command that makes me a sorted text file with every human user's name in it.

12) Write me a command that prints every line in /etc/passwd with a ":0:"?

13) Why do I care about such lines?

14) Does the system have any user who's name starts with an 'a'?

15) Run the 'df' command.  What does it do?

16) Run the 'du' command.  What does it do?  How about 'du -s *'