CMSC104 Spring 2010 Unix Lab Exercise

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/d/b/dblock/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 as you saw with ls, but with more information about each. Note that it is -l (the letter l, not the number 1).

   
   

   linux1[6]% ls -l
   total 6
   drwx------    2 dblock   rpc          2048 Sep 19 09:04 Mail
   drwx------    2 dblock   rpc          2048 Sep 19 09:04 bin
   lrwx------    2 dblock   rpc          2048 Sep 19 09:04 www -> ../pub/www
   -rw-------    2 dblock   rpc          1024 Sep 19 09:04 mybio.txt
   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. Now, in the next few steps, you are going to create directories for your projects. There is no directory for hw2 because you will turn that in on paper. The directories will be created in your www directory, where your JavaScript projects must be stored in order to be seen on the Web. You must create these directories with the exact names I give you, including spelling and upper or lowercase. You need to go up to the parent directory of your home directory.

linux1[19]% pwd
/afs/umbc.edu/users/d/b/dblock/home/
linux1[20]% cd ..
linux1[21]% ls
Mail  backup  home  pub
linux1[22]%

7. Now, change into the pub directory. Look at the contents of the directory.

linux1[23]% pwd
/afs/umbc.edu/users/d/b/dblock/
linux1[24]% ls
Mail  backup  home  pub
linux1[25]% cd pub
linux1[26]% ls
www
linux1[27]%

8. Change into the www directory. Then, create a subdirectory called cs104. Verify that is exists.

linux1[28]% cd www
linux1[29]% mkdir cs104
linux1[30]% ls
cs104
linux1[31]%

9. Change into the cs104 directory. (Make sure you are there!) Create subdirectories called hw3, proj1, proj2, proj3 and proj4. (Shortcut: Remember the up arrow will repeat the last command. This might be helpful when creating the subdirectories.) When you have finished verify that the subdirectories exist.

More Practice with Directory and File Commands

1. Move to your home directory. Make sure you are there. Check for your directory by using the command: pwd. What command should you use if you are not in your home directory? Ask if you are not sure!

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. Eat dinner.


   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/d/b/dblock/home/
    linux1[35]% mkdir PersonalBackup
    linux1[36]% ls
    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
      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
    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.

13. Please have your instructor inspect your work before you logoff. If you do not complete the lab today and would like to finish later, you can continue to work on it from home. In that case, make sure your instructor inspects your work at the start of the next lab session.

Be sure to logout completely when you have finished!