CMSC 104 -- Problem Solving & Computer Programming | Section 0101, Instructor: John Y. Park   HOME|SYLLABUS|SCHEDULE|ASSIGNMENTS|RESOURCES|CONTACT ME

Objectives

Note: There is nothing that you must turn in associated with this exercise. If you do not finish the exercise during the lab session, it is to your benefit to finish it later on your own.

The Assignment

Follow the steps below in order. Notice that you are not always given the full command to use. As you move through the exercise, you are given fewer and fewer commands. It's time to think! Use your class notes as a reference.

Creating a Directory Hierarchy (Tree) To Use During the Semester

1. Log into your gl account.

2. Look at the name of your home directory.

   linux1[2]% pwd
   /afs/umbc.edu/users/p/a/park/home   
   linux1[3]%    
   
   

3. Look at the contents of your home directory. It might contain the following (and possibly more or less) files and subdirectories:

   linux1[4]% ls
   Mail  bin  www  mybio.txt
   linux1[5]%
   
   

4. Look at the "long" contents of your home directory. You should see the same subdirectories, but with more information about each.

   linux1[6]% ls -l
   total 6
   drwx------    2 park rpc  2048 Sep 15 09:04 Mail
   drwx------    2 park rpc  2048 Sep 15 09:04 bin
   -rwx------    1 park rpc  1024 Sep 15 09:04 mybio.txt
   lrwxr-xr-x    1 park rpc  2048 Sep 15 09:04 www -> ../pub/www
   linux1[7]%
   
   

   
   

5. Look at the "hidden files in your directory. If you can't remember how to do so, use the man pages (man ls). Look for the option that will show "all" files including those that are hidden (files starting with a period). To exit out of the man page, you should type 'q' for quit.

6. Create a subdirectory called cs104. Verify that it has been created by again looking at the contents of your home directory.

   linux1[8]% mkdir cs104
   linux1[9]% ls
   cs104  Mail  bin  www  mybio.txt
   linux1[10]% 
   
   

7. Move to the cs104 directory. Verify that your current directory is now indeed cs104 (Remember that linux is case sensitive...so cs104 is different from CS104.)

   linux1[11]% cd cs104
   linux1[12]% pwd
   /afs/umbc.edu/users/p/a/park/home/cs104
   linux1[13]%    
   
   

8. Create six new subdirectories, one for each of the assignments that you will be doing in this class. Call them hw1, hw3, proj1, proj2, proj3 and proj4. There is no directory for the second homework because you will turn it in on paper. Verify that each of the subdirectories has been created.

9. Move your mybio.txt file from your home directory into the hw1 directory. Check to see that it is no longer in your home directory. Then, check to see that it is in the hw1 directory. You should be in the cs104 directory when you issue these commands.

   linux1[14]% pwd
   /afs/umbc.edu/users/p/a/park/home/cs104   
   linux1[15]% mv ../mybio.txt hw1
   linux1[16]% ls ..
   cs104  Mail  bin  www
   linux1[17]% ls hw1
   mybio.txt
   linux1[18]%
   
   

10. Move back to your home directory. Is there more than one way to get there? If so, try using a way that you have never used before. Verify that your current directory is indeed your home directory (use pwd).
    
    

More Practice with Directory and File Commands

1. Move to your home directory. Make sure you are there (pwd).

2. Create a new directory named Personal. Verify that the directory exists.

3. Move to the Personal directory. Verify that you are there.

4. Use the xemacs editor to create a file called things2do.txt.

   linux1[32]% xemacs things2do.txt
   linux1[33]%
   
   

   Once you have opened the file, you should type the following:

   
   1. Finish today's lab exercise.
   2. Finish homework 1.
   3. Bring my pet tarantula to CMSC104 for Show'n'Tell
   
   

   Save the file and exit xemacs. In case you forgot how to save, it's ctrl-x ctrl-c and then press 'y' for yes.

5. Look at the contents of the current directory. It should contain just the things2do.txt file.

6. Display the contents of things2do.txt on the monitor (cat things2do.txt OR more things2do.txt OR less things2do.txt). To exit out of less, you should type 'q'.

7. Move back to your home directory. Verify that you are there.

8. List the contents of the Personal directory (ls Personal). It should contain only the file things2do.txt.

9. Make sure you are in your home directory! Create another subdirectory called PersonalBackup in your home directory. Verify that it exists. Both Personal and PersonalBackup should be in your home directory.

10. 
    

    linux1[34]% pwd
    /afs/umbc.edu/users/p/a/park/home/   
    linux1[35]% mkdir PersonalBackup
    linux1[36]% ls 
    cs104  Mail  bin  www  Personal  PersonalBackup
    linux1[37]%
    
    

    • Copy the file things2do.txt from Personal to PersonalBackup.

      linux1[38]% cp Personal/things2do.txt PersonalBackup
      linux1[39]%
      
      

    • Look at the contents of the PersonalBackup subdirectory. It should now contain the file things2do.txt.

11. Try to delete the Personal subdirectory. You will get a message that the directory is not empty. You must delete all files and subdirectories from a directory before deleting the directory itself. So,
    • Delete things2do.txt from Personal.
    • Look at the contents of Personal to make sure that it is empty.
    • Delete the Personal subdirectory.
    • Look at the contents of your current (home) directory to make sure that Personal has been deleted.

      linux1[40]% rmdir Personal/
      rmdir: `Personal/': Directory not empty
      linux1[41]% rm Personal/things2do.txt
      rm: remove regular file `Personal/things2do.txt'? y
      linux1[42]% ls Personal/
      linux1[43]% rmdir Personal
      linux1[44]% ls
      cs104  Mail  PersonalBackup  bin  www
      linux1[45]%
      
      

12. Move things2do.txt from the PersonalBackup directory to your current (home) directory.

    linux1[46]% mv PersonalBackup/things2do.txt .
    linux1[47]% ls
    cs104  Mail  PersonalBackup  bin  things2do.txt  www
    linux1[48]% 
    
    

    • Look at the contents of your home directory to be sure that things2do.txt is there.
    • Look at the contents of PersonalBackup to be sure that things2do.txt is no longer there.
    • Delete the PersonalBackup subdirectory.
    • Delete things2do.txt.

Be sure to logout completely when you have finished!