IT 244: Introduction to Linux/Unix - Class 20 Exercise, Thursday, May 6th

IT 244: Introduction to Linux/Unix
Class 20 Exercise, Thursday, May 6th

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.

Execute the script command, using the --flush option

    script --flush

Run history
```
    history
```
The list you see here is every one of your last 500 command lines.
Display your last 10 command lines
```
    history 10
```
When you give history a numeric argument, it lists only that number of commands.
Execute again some previous command using the event number
```
    !EVENT_NUMBER
```
where EVENT_NUMBER is a number you obtained from the history command.

Notice that the old command line appears first, and then the output that the command line produced.
Execute again some previous command using the first letter of that command line
```
    !h
```

Display HISTFILE
```
    echo $HISTFILE
```
This is the file that contains your history record.
Examine the most recent contents of your history file
```
    tail $HISTFILE
```
Display HISTFILESIZE
```
    echo $HISTFILESIZE
```
This is the maximum number of command lines the history mechanism will record in ~/.bash_file when you quit
Count the number of lines in your history file
```
    wc -l $HISTFILE 
```
The wc (word count) command with the -l option counts the number of lines in the file given to it as an argument.

The number this command returns should be less than our equal to the value of HISTFILE.
Display HISTFILESIZE
```
    echo $HISTSIZE
```
The value of this variable sets the maximum number of command lines saved by the history mechanism between individual terminal sessions.

Use the exit command

    exit

You should see a confirmation message confirming that the script is finished, resulting in a file called typescript

Go to my home directory and execute pwd on the same line
```
    cd ~ckelly ; pwd
```
Run fc
```
    fc
```
The command line you just entered appears in an editing window.
Edit the command line

Make it read like this:
```
    cd ~; pwd
```
Save changes and quit

Save these changes (Control O) and quit (control X), using the key combinations you see at the bottom of the editing window.

The command line you just edited should appear first, followed by the output of the edited command.

The edited command line has taken you to your home directory.
Look at your last 16 command lines
```
    fc -l
```
Edit some command line using its event number
```
    fc EVENT_NUMBER
```
Make some changes save and quit.
Edit the last call to history
```
    fc h
```
Change the command to read
```
    history 5
```
Save these changes and quit
The edited command will now run.

Tell the instructor you have finished making changes to .bash_profile

There is no Bash script for this Class Exercise.

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 20 Exercise, Thursday, May 6th