1. Check if a file exists.  Print a message saying whether a given file exists.
    Example: ./maybe /etc/passwd
    Output: /etc/passwd exists

2. Print "On the net" or "Disconnected" depending if you can ping 8.8.8.8
   Example:  ./netstatus
   Output:  On the net


3. For both the Apache web log, and the Apache error log, 
   print every occurence of the argument
   Example:  ./checklogs pig.jpg
   Output:  (A bunch of lines from the log files)

4.  Print your current public IP address.
    Usage:  ./myip
    Output: 203.0.113.47


5. Simple countdown timer.  Count down from a given number of seconds and alert when done.
   Example: ./countdown 5
   Output:
      5
      4 
      3
      2
      1
      Done

6. Check disk usage on /. If it is over 80% full, print a warning. Otherwise print "Disk OK".
    Usage:  ./diskwarn
    Output: WARNING: disk is 87% full
    or:  Disk OK

7. Rename all .txt files to .bak Batch rename every .txt file in the current directory.
   Example:  ./bakups
   Output:  (none.  It just does the job)