CMSC 104, Fall 2006

Homework 3

Your First C Program

Out:Thursday, October 12th
Due:Thursday, October 19th, before 11:59 p.m.

Note: No late projects will be accepted.

The Objective

To learn to use the gcc compiler
To become familiar with syntax error messages generated by the gcc compiler

The Task

For the first part of the assignment, you must complete the program attached to this sheet (to be distributed in class) by filling in the blanks where pieces of code are missing. After filling in the blanks, you are ready to move on to the second part of the assignment. For the second part, use a text editor to type in the C program. Type it in EXACTLY AS SHOWN, including all spacing. (Three exceptions in the header comment: 1) insert YOUR name as the author and 2) insert YOUR e-mail address. 3) insert YOUR section.) Make sure to save the program with the file name hw3.c.
Compile the program using the command
```
          gcc -ansi -Wall hw3.c
```
Correct any compilation errors (if any) that you receive and recompile until you receive no errors.
Look at your directory to make sure that the file a.out is there. This is your executable program.

Run the program a few times using different sets of numbers to be sure that it works. To run your program, type a.out at the prompt. You can assume the user will only input positive integers. Here is a sample run of the program:

linux3[54]% ls
hw3.c  
linux3[55]% gcc -ansi -Wall hw3.c
linux3[56]% ls
a.out  hw3.c  
linux3[57]% a.out
Please enter an integer: 7
Please enter another integer: 9
9 is larger than 7.
The average of 7 and 9 is 8.000000.
linux3[58]% a.out
Please enter an integer: 9
Please enter another integer: 7
9 is larger than 7.
The average of 9 and 7 is 8.000000.
linux3[59]% a.out
Please enter an integer: 7
Please enter another integer: 7
7 and 7 are equal.
The average of 7 and 7 is 7.000000.
linux3[60]% a.out
Please enter an integer: 5
Please enter another integer: 9
9 is larger than 5.
The average of 5 and 9 is 7.000000.
linux3[61]% a.out
Please enter an integer: 5
Please enter another integer: 8
8 is larger than 5.
The average of 5 and 8 is 6.500000.
linux3[62]%

Submitting the Program

You do not have to turn in the sheet you used to fill in the blanks. However, you do have to submit your source code. Your C source code file MUST be called hw3.c. To submit your project, type the following at the Unix prompt. Note that the project name starts with uppercase 'H'.

submit cs104_0101 Hw3 hw3.c

-OR-

submit cs104_0501 Hw3 hw3.c

To verify that your project was submitted, you can execute the following command at the Unix prompt. It will show the file that you submitted in a format similar to the Unix 'ls' command.

submitls cs104_0101 Hw3

-OR-

submitls cs104_0501 Hw3