IT 244: Introduction to Linux/Unix - Class 4 Exercise, Tuesday, February 9th

IT 244: Introduction to Linux/Unix
Class 4 Exercise, Tuesday, February 9th

When finished: Remember to check with instructor to make sure you are recorded as having completed the class exercise!

Today we are going to practice using the Unix utilities covered in class.

If you have any difficulty with any part of this assignment, please talk to me immediately.

Log in to pe15

Run the ssh client
Use the values in the table below to connect to pe15.

ssh configuration parameter	value
protocol	ssh
ssh version	2
ssh port	22
host	pe15.cs.umb.edu
user name	your unix username
Authentication method	password

Enter your password
A dialog box will appear on the screen into which you must type the password for your Unix account.
Make sure you are in your home directory
```
    cd
```
Go to your it244 directory
```
    cd  it244
```
Go to your ex directory
```
    cd  ex
```
Create an ex04 directory
```
    mkdir  ex04
```
Go to your ex04 directory
```
    cd  ex04
```

Experiment with Special Characters

Try using & in a directory name
```
    mkdir  abc&def
```
You should get an error message
Look at the results
```
    ls
```
mkdir created an abc directory and then tried to execute the non-existent command def
Remove the abc directory
```
    rmdir abc
```
Check that the abc directory is gone
```
    ls
```
Use the backslash, \ , to continue a command onto the next line
```
    echo foo \[Enter]
    bar [Enter]
```
There should be no space between the \ and the newline created by the Enter key.

The shell did not process what you entered on the first line after you pressed the Enter key for the first time, it just gave you a new line.

The backslash, \ , turned off the special meaning of the newline character.

Create a typescript File

Make sure you are in your ex04 directory
```
    pwd
```
If the result of running this command is not
```
    ~YOUR_UNIX_USERNAME/it244/ex/ex04
```
where YOUR_UNIX_USERNAME is the name you created for your Unix account, see me.
Run the script command
```
    script --flush
```
This will create a typescript file in your ex04 directory.

You must perform the remaining steps in this exercise while script is still running.

If you make a mistake, simply try again.

Do not exit the script session until you have finished all the steps in this exercise.

Working with ls

Move to your home directory
```
    cd
```
Make sure you are in your home directory
```
    pwd
```
Run ls without options or arguments
```
    ls
```
You see only the visible files in your home directory
Look at the contents of your it244 directory
```
    ls  it244
```
Look at all the files in your home directory
```
    ls  -a
```
Get a long listing of all the files in your home directory
```
    ls  -al
```
Notice that you can use more than one option at a time.

cat

Run cat on your .bash_history file
```
    cat  .bash_history
```
Now run cat showing line numbers
```
    cat  -n  .bash_history
```

mkdir

Go to your ex04 directory
```
    cd  it244/ex/ex04
    pwd
```
Create a test directory
```
    mkdir  test
```
Make sure the directory was created
```
    ls
```
Create a test2 directory
```
    mkdir test2
```
Look at the contents of your current directory
```
    ls
```
You should see the a new test2 directory

Experiment with rm

Move to your test2 directory
```
    cd  test2
```
Create some files in this directory
```
    touch  foo  bar  bletch  gobble
```
touch will create a file if it doesn't already exist.

That is not its primary purpose, but we'll only be using it in this way for this class.
Perform a long listing of the contents of the test2 directory
```
    ls  -l
```
The first entry after -rw-r--r-- for each file is a 1. This means the files are one byte long, essentially empty.

touch creates empty files.
Remove the file foo
```
    rm foo
```
Look at the directory contents
```
    ls
```
Remove bar and bletch
```
    rm  bar  bletch
```
List the contents of your current directory
```
    ls
```
All the three files you removed should be gone.
Remove a file using the -i option
```
    rm  -i  gobble
```
Enter y when prompted
Create some more empty files
```
    touch  baloney  ham  cheese  turkey
```
Look at the directory contents
```
    ls
```
You should see the files you just created.
Remove all files from your current directory
```
    rm  *
```
Look at the directory contents
```
    ls
```
The directory should be empty

rmdir

Make sure you are in your test2 directory
```
    pwd
```
If not, go there.
Create some files
```
    touch  red  blue  green  orange
```
Move back up to the ex04 directory
```
    cd  ..
```
Examine the contents of the test2 directory
```
    ls test2
```
Try to remove the test2 directory using rmdir
```
    rmdir test2
```
You should get an error message because the directory is not empty
Look at the contents of your ex04 directory
```
    ls
```
The test2 directory is still there.
Remove the files in test2
```
    rm  test2/*
```
Remove the test2 directory
```
    rmdir  test2
```
Examine the contents of your ex04 directory
```
    ls
```
The test2 directory should be gone

Run cp to Copy Files and Directories

Create a file
```
    touch  foo
```
Copy a file
```
    cp  foo  footoyou
```
Look at the contents of the directory
```
    ls
```
Go to the test directory
```
    cd test
```
Create some files in this directory
```
    touch  foo  bar  bletch
```
Go back to the ex04 directory
```
    cd ..
```
Copy a directory
```
    cp  -r  test  test3
```
Look at the contents of the ex04 directory
```
    ls
```
You should see a new test3 directory
Look at the contents of test3
```
    ls  test3
```
It should be the same as test

mv

Go into the test3 directory
```
    cd  test3
```
Change the name of footoyou
```
    mv  foo  foo_to_you
```
Examine the changes
```
    ls
```
Move a file to another directory
```
    mv foo_to_you ../test
```
Look at the contents of the current directory
```
    ls
```
foo_to_you is no longer in your current directory
Look at the contents of your test directory
```
    ls ../test
```
foo_to_you has been moved to the test directory

End your script Session

Exit from your script session
```
    exit
```
You need to do this or the typescript file will never be created
Look at the contents of the typescript file
```
    cat  typescript
```

When finished:

Remember to check with instructor to make sure you are recorded as having completed the class exercise.
When you are ready, be prepared to show me:
- Your command line interaction -- in other words, scrolling up in the terminal windows, not just running the history command!
- Any other deliverables specified in the instructions, such as scripts or other files.

IT 244: Introduction to Linux/Unix Class 4 Exercise, Tuesday, February 9th