Name:
Date:

Exercise Linux

Save this file in one of your directories. Using an editor (vi or emacs), open this file and 
type in your answers.  Please include the questions with your responses.  Email the completed 
exercise to larson@astro.washington.edu.

Deadline: 

1. (1 pt) Confirm that you have changed your password by initialing here ____ .  You used what 
command to accomplish the change in your password?

2. (1 pt) Go to your home directory if you are not already there.
If you type the command 	cd ..       what directory are you in
relatively speaking (that is, no matter where you were)?
What directory are you in absolutely speaking?

3. (1 pt) How did you find out?


*************************************
Now type      

cd           

in order to return to your home directory. Create a subdirectory called test.

4. (1 pt) What is the relative pathname to the test directory, from your home directory?

5. (1 pt) What is the absolute pathname to test?

6. (2 pts) Type

kill bill

What response do you get?  Why did you get it?

************************************
In the directory test, edit a file called bill and copy  the following lines exactly as shown:

	#### a way to kill bill ####
	ls -R /net/projects/ > out.txt


7,  (2 pts)  What are you asking the computer to do, exactly?  ("Kill Bill" is
not the answer!)

Make the file bill executable (able to run) by typing in chmod +x bill

8.  (1 pt)  What is done when you use chmod? How would you change this command
so that only the user could execute the file?

9.  (1 pt) You are going to run bill as a background job. 
How would you "kill bill"?  It is important to get this right since
the above command sets up a very bad loop!

*********************************
Now, type 

bill &
      
Hit return (enter) again (you should see something about suspended) then

10. (2 pts) Go ahead and

kill bill

then type:  

jobs   

and write down exactly what the computer responded with:

********************************
There is a file called foo.txt in my home directory. Copy this over to your own home directory.

11. (3 pts) On what date and time was this file created in *your* directory?  When was it 
created in my directory?  How large of a file is it? (You'll need to use ls -l. The entry just 
to the left of the date is the file size in bytes)

12.  (1 pt) What permissions do the owner, group, and others have?

13. (1 pt) Now figure out how you could generate a full listing of all the files in your home 
directory (even the subdirectories), and append it to the end of the file foo.txt.  Take a look 
at the file to make sure you've accomplished this successfully.  Make this happen, and write 
down the exact command you used (including any flags and re-direction) here:

14. (1 pt) How large is foo.txt now?

15.  (2 pts) What does a pipe let you do?  Write down an example that you might want to use.

16.  (1 pt) Let's say you have a few files that are ridiculously huge, but that you want to 
keep.  What command would you use to compress them?

17.  (3 pts) You should have already copied over a series of files into a directory called 
exercise1.  This directory is for IRAF use.  Change to that directory, and create a tarball of 
those files. What command and flags did you use?  Create another directory, move the tarball to 
that directory, and extract the files. What command did you use?