IT 116: Introduction to Scripting

IT 116: Introduction to Scripting
Class 2 Exercise

The Class Exercises are designed to give you hands on experience
All work for this course will be done on the Unix machine users3
In this exercise you will learn to do four things ...
which you need to know for this course
- Connecting to a Unix machine
- Running Python in interactive mode
- Creating directories for your class work
- Creating a Python script
I have created a video which demonstrates the last two topics

Install putty.exe if you have a Windows machine
Download it from https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html.
For more information go to https://www.cs.umb.edu/~ghoffman/linux/remote_access_windows.html
Run the Terminal program if you have a Mac
You will find this program in the Utilities directory inside the Applications directory.
For more information go to https://www.cs.umb.edu/~ghoffman/linux/remote_access_mac.html
Run an SSH client
Run putty.exe if you have a PC or Terminal if you have a Mac.
Enter appropriate information
You want to connect to users3.cs.umb.edu.
If you need a port number use 22.
The account name is the name you used when you ran the apply program.
Enter your password

Enter Python interactive mode
```
python3
```
Be sure you type "python3", not "python".

Typing "python" will run the wrong version of the Python interpreter.
Use the help() function
```
>>> help("topics")
```
Use this function to learn more about assignment in Python
```
>>> help("ASSIGNMENT")
```
Advance through this help entry

Keep hitting Space until you get to the end.
Quit this help entry

Type q to quit.
Create some variables
```
>>> a = 5
>>> b = 6
>>> c = 10
```
Check the values you have just entered
```
>>> a
>>> b
>>> c
```

Perform some arithmetic

>>> a + b + c
>>> a * b + c
>>> a * b * c
>>> a * b / c

Print some phrases

>>> print("Hello world!")
>>> print("Go Red Sox!")

For help with the work below, see this video.

Go to your home directory
```
cd
```
Go to your it116 directory
```
cd  it116
```
If you do not have an it116 directory, DO NOT CREATE AN IT116 DIRECTORY
Come to me instead
Create the ex directory
```
mkdir  ex
```
Check that the directory was created
```
ls
```
Create the hw directory
```
mkdir  hw
```
Check that the directory was created
```
ls
```
Go to your ex directory
```
cd ex
```
Make sure you are in your ex directory
```
pwd
```
If you are not in /home/UNIX_ID/it116/ex, see me.
Create a directory for this exercise
```
mkdir  ex2
```
Check that the directory was created
```
ls
```
Go to this new directory
```
cd ex2
```

Create the script ex2.py using the nano text editor
```
nano  ex2.py
```
You must run this command while you are in your ex2 directory inside you ex directory.
Enter the text for this script
```
print("Hello world!")
```
Save your changes
```
Control O
```
The name of the file will appear in black toward the bottom of the screen.

Hit Enter or Return to make this go away and save the file.
Quit nano
```
Control X
```
Run this script
```
python3  ex2.py
```
You should see
```
Hello world!
```
Let me check your work

Come to me so I can check your script.

If you want to run my text script on your Class Exercise script do the following
Run ex02.sh on your script
```
~ghoffman/it116_test/ex03.sh
```
The script will prompt you for your Unix username.