The purpose of this assignment is to familiarize you with the mechanics of preparing and submitting assignment solutions. This assignment carries no grade, but you must do the electronic submission. Follow these instructions if you want to use the LCC-Win32 system on your Windows PC. We provide different instructions if you prefer to use OS X on your Macintosh or Unix on the arizona workstations. Your goal this week is to learn to use LCC-Win32 system for editing and compiling programs.

If you have programmed before and are familiar with the Windows operating system, you may be able to finish this assignment quickly on your own. If you have not programmed before, or are hesitant about using Windows, we recommend that you bring your laptop and a network cable to the Friends center lab, and work on the assignment there. The lab will be staffed with knowledgeable TAs who can assist you. Don't be afraid to ask for help.

Your assignment is to create, compile, run and submit three short C programs. In addition, you will edit and submit a descriptive file called readme.txt with each of your assignments. (Instructions for the readme file are on the checklist for each assignment.)

PROGRAM 1 hello.c : Create, compile, run and submit the following extension of everybody's first C program.

#include <stdio.h>

int main(void) {
    int num;
    printf("Hello world! Give me an integer:\n");
    scanf("%d", &num);
    printf("Thanks! I've always been fond of %d.\n", num);
    return 0;
}

PROGRAM 2 hello-while.c : Create, compile, run and submit Hello World Exercise #5.

PROGRAM 3 hello-if.c : Create, compile, run and submit Hello World Exercise #6.

Completing this assignment involves a number of steps that are described below. The instructions refer to Program 1, but will be the same for Programs 2 and 3. These instructions were written for Windows 2000 users, but you should be able to adapt them if you are using a different version of Windows.

Setting Up and Logging In

• Install the LCC-win32 compiler system and other Windows software by following these Windows instructions.

• Open a DOS Command Prompt by selecting Start -> Programs -> Accessories -> Command Prompt.

• Create a subdirectory to store your C programs. In the window containing the DOS Command Prompt, type the bold commands below:

  C:\WINDOWS>cd C:\
  C:\>mkdir cos126
  C:\>cd cos126
  C:\cos126>mkdir hello
  C:\cos126>cd hello
  C:\cos126\hello>
  

  The mkdir command creates a new directory; the cd command changes the current working directory. After executing these commands, your working directory is the newly created C:\cos126\hello. All of your files for Assignment 0 will go here.

  Don't be scared by the DOS Command Prompt - you will only need to use a few basic commands. Keep this window open. You will use it in the Compiling and Executing sections of this assignment.

Now you are ready to write your first program.

• Launch LCC-win32 via Start -> Programs -> lcc-win32 -> lcc-win32 if it is not already open..

• In the LCC-Win32 window, select File -> New -> File. Type

  c:\cos126\hello\hello.c
  

  and click OK.

• Enter the C program exactly as it appears above. If you omit even a semicolon, the program won't work.

• When you're done, save the program using File -> Save.

Compiling the program

• It is now time to convert your C program into machine executable code. From the DOS Command Prompt, type

  C:\cos126\hello\>c:\lcc\bin\lcc126 hello.c

  If lcc complains in some way, you mistyped something, and you should check your program carefully. Ask for help if you can't see the mistake.
  

• If everything went well, you should see the following in the DOS Command Prompt:

  C:\cos126\hello\>c:\lcc\bin\lcc126 hello.c
  C:\cos126\hello>c:\lcc\bin\lc -A -ansic hello.c
  

Executing the program

• At the DOS Command Prompt, type

  C:\cos126\hello\>hello

  This command executes your program. You should get

  Hello world! Give me an integer:

  in the window. Then nothing will happen. You must type an integer (say, 5), and hit Enter, then you will get

  Thanks! I've always been fond of 5.

  and the program should terminate. You may need to repeat this edit-compile-execute cycle a few times before it all goes smoothly.

Submitting the program

• Once you have hello.c working, submit it via the Web. To do this, launch your favorite browser and go to the COS 126 web page:

  http://www.princeton.edu/~cs126

  choose the Assignment Submission menu option, and follow the instructions provided.

• You will receive an email confirmation of your submission.

Browsing the COS 126 home page

• The final part of the assignment is to browse the COS 126 Web pages. The address is:

  http://www.princeton.edu/~cs126

  Cruise around the COS 126 Web site; it is essential that you understand what's where and how to get to it. Be sure to fill out the online questionnaire. Also make sure you find the "Assignment 0 Checklist" page, and also be sure to read the COS 126 Collaboration Policy.