COMP151: Lab 02

Objective:

To practice using separate compilation and makefiles

Download :

Date_all.cpp: contains the class definition and implementation of class Date, and main function

Lab work:

What's class declaration, definition and implementation?

	C++ code	Explanation
class declaration	`class Date;`	Introduce a class called "Date" to the complier, but without any detail information.
class definition	`class Date { Date(); //... };`	Define the class Date's member variables & member functions.
class implementation	`Date::Date() { //... }; //...`	Generate the code of class Date.

Why use separate compilation?

Separate the interface and the actual implementation

Clean & concise header files (*.h)
Separate the compilation process to prevent re-compilation of unecessary components when program is changed

What's makefile?

"Auto" compile many files at once! and more!

Code in makefile Explanation

#
#Comp151, Lab02
#Basic Makefile under Unix Everything after the character "#" is a comment.

date.o: date.h date.cpp
g++ -c date.cpp

If ((date.o does not exist) or (date.h or date.cpp is modified)), then run "g++ -c date.cpp".

Attention: it is a tab before "g++", NOT spaces!

Assessment tasks:

To make use the idea of separate compilation. You should first download the file Date_all.cpp which contains the Date classes' declarations, implemntation and a short main program. You should then separate the Date class declaration and implementation into separate files and also put the program into a separate file.

Put the class Date's declaration into Date.h
Put the class Date's implementation into Date.cpp
Put the main function into main.cpp

Change the main program to an interactive one that asks the day, month and year and then prints it.

Write a makefile that compiles the programas as follows:

First compile date.cpp to generate object code date.o
Then compile main.cpp to generate object code main.o
Finaly, link the object codes and generate an executable code with filename"lab02"

Compile the program by typing

"gmake" to compile the program into executable code

Submission:

Put your files (date.h date.cpp date.o main.o main.cpp Makefile lab02) into ~/comp151/lab02
The system will collect your files on Thursday 15 February at 12.00 o'clock midnight.
Note that due to the deadline of the add/drop period (Wednesday 14) the collection day for this week's labs (1A,1B and 1C) is Thursday midnight. Starting from next week the lab collection deadline will be at midnight of lab day, i.e., Tuesday midnight for lab 1A and Thursday midnight for labs 2B and 2C.

Redirection in Unix

After you finished the program, try the following commands to see what they do:

"lab02 < input.txt" to read input from file
"lab02 < input.txt > output.txt" to read input from file and output to file