DISCOVERY EXERCISES
1. Use the whatis command to determine the purpose of the ls command. whatis ls ls (1) ­ list directory contents 2. Use the man program to find out what the ­R option does when used with the date command. ­R, ­­rfc­2822 output date and time in RFC 2822 format. Example: Mon, 07 Aug 2006
12:34:56­0600

3. Use the man program to determine what other commands you should also see in relation to the clear command.
SEE ALSO tput(1), terminfo(5) 4. Use the cal command to determine on what day of the week you were born. user:~$ cal 8 1989 August 1989
Su Mo Tu We Th Fr Sa 1 2 3 5
4

6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30 31

5. Use the cal command to determine which years between 2006 and 2015 are leap years. user:~$ cal 2 2008 February 2008
Su Mo Tu We Th Fr Sa 1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 6. Clear the screen, and view the online manual to determine how to display today’s date in UTC. ­u, ­­utc, ­­universal print or set Coordinated Universal Time 7. Display the current UTC. user:~$ date ­­utc
Tue Jan 19 11:01:14 UTC 2016

8. Create a file called month containing the current month. user:~$ cat > month user:~$ cal 1 2016 >> month 9. View the contents of the month file you created in Exercise 8. user:~$ less month
January 2016
Su Mo Tu We Th Fr Sa 1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31
month (END)

10. Use the who command to determine the idle time for users currently logged in, but output that information to a file called users_info. Next, view the file you created. user:~$ who ­u >user_info