COMPUTER PROGRAMmING

Part 4: Scripting and Virtualization (due Week 7)

Objectives

1. To learn scripting on Windows and Linux

2. To add virtualization with a Linux distribution

Steps

Part 1—Windows Scripting

Basic Script: Scripting is useful for small programming projects or quick tasks. Often, these programs are short and meant for small problems. Unlike compiled programming languages, scripting languages are generally interpreted. Batch files or scripts are created to automate tasks and may contain several commands in one file. Scripts can be created in Notepad. These are short files that run each command in sequence at file execution. The windows command-line interface can be used to run scripts.

Below are some commands.

Echo = Displays a message in the batch file

Echo. displays a blank line

@command turns off the display of the current command

@echo off = does not echo back text

cls = clears your screen

:: = Adds comments to your code; this line will not be displayed

Start = used to start a windows application

Creating a Basic Script

cls

@echo off

::Your Name

echo "Creating a data dump file"

ipconfig /all > C:\Scripts\config_info.txt

echo end of script

Open Notepad by going to Start-> All Programs -> Accessories-> Notepad.

Type the above script into Notepad.

Create a directory named Scripts on the C:\ drive. Save this file in the C:\Scripts folder as myscript.cmd.

Do not close your Notepad file. To run, open a command prompt by typing cmd in the Search Programs and Files box when you click the Start button or search for cmd.

Change directory to the C:\Scripts folder by typing the following.

cd c:\Scripts

Then type in the following.

myscript.cmd

The script should run and will create a file.

Use the dir command to see what files are created.

Keep both the Notepad file and the command prompt open for the next step.

You can also shut down a computer from a script. This is helpful for remote shutdown in a networking situation. Add the following commands to your script and save it in Notepad. (Note: The ping command, though normally used for networking, here waits 4 seconds.)

shutdown /s /t 60 /c "Local shutdown in 1 minute!"

ping -w 1000 0.0.0.0 > nul

shutdown /a

echo "Shutdown has been aborted"

Click back to the command prompt.

Type in myscript.cmd to run the script.

You should see the script attempt to shut down, then abort the shutdown.

Keep both your Notepad and command prompt open.

Environment variables are built-in system variables available for all Windows processes describing users, paths, and so on.

Some common environment variables are as follows.

%PATH% = contains a list of directories with executable files, separated by semicolons. To add a path:

SET PATH = %PATH%;C:\Windows\Eclipse

%DATE% and %TIME% = current date and time

%RANDOM% = returns a random number between 0 and 32767

%WINDIR% = points to the windows directory C:\Windows

%PATHEXT% = displays executable file extensions ie .com, .exe, .bat, .cmd, .vbs, .vbe, .js, .wsf, .wsh

%USERNAME% = the current user

Add the following commands to your script.

echo "The date is "

echo %DATE%

echo "The path is "

echo %PATH%

Run your script in the command prompt.

Now modify the script to display all the files in the directory (dir command) before the shutdown command and display two more environment variables.

Take a screenshot of your script after running it and paste it in the lab report. Also paste your final script.

The next script will be creating a backup script. In order to do this you will need to determine what files you want to back up, and the destination. You may want to back up school files, pictures, important documents, and so on. The files you will backup will need to be in a specific folder (i.e., C:\Users\Susie\Documents\Files). Then you will need a separate place to back up your data. It could be a separate folder on your C: drive, or it could be an external drive or USB drive.

You will also give your backup folder a custom name with the date. However, to do this you will need to strip out the / signs in the date. If you keep the / signs in the date, then when you create your backup folder there will be several subfolders. For example, see the date below:

If we were to make a folder with the name backup_%date% it would have a confusing set of spaces and slashes:

So we need to strip out the month, day, and year. We do this by extracting a position and number of characters. So this command: %date:~4,2% will start at the fourth character and extract two characters with the result of 07. To pull out the month, day, and year, use the following command. %date:~4,2%%date:~7,2%%date:~10,4%

We will use this to create our backup folder name.

Next, we will use the xcopy command to copy all files and subdirectories. The xcopy command works like this: xcopy source destination

So if you want to copy files from your C:\users\gina\Documents\work\ to your E:\backup (E: is the USB drive in this case) you would use this command: xcopy C:\users\gina\Documents\work\* E:\backup\* /S /Y /I

Note that switch S will copy all files and folders including subfolders, Y will overwrite files and not ask for confirmation, I will automatically create subfolders.

Below is an example backup script. Replace Sheldon Cooper with your own name and replace the pathnames of the source and destination.

Take a screenshot of your script and paste it in the lab report. Also paste a screenshot showing your folder created for your backup.

Part 2 Linux Virtualization and Scripting

For this part of the lab, we will be using the Linux operating system. If you do not have a Linux environment, you can set one up using VMWare using the steps below: