LAB 1 INTRODUCTION TO LINUX ENVIRONMENT AND C COMPILER

Transcription

1 LAB 1 INTRODUCTION TO LINUX ENVIRONMENT AND C COMPILER School of Computer and Communication Engineering Universiti Malaysia Perlis 1

2 1. GETTING STARTED: 1.1 Steps to Create New Folder: Click Places icon > Home Folder > Go to File menu > Create Folder Rename the New Folder as your Matrix No. 1.2 Steps to Start the Text Editor: Click Applications icon > Accessories > Text Editor (you are now in gedit editor) Once the gedit text editor started, automatically it will view an untitled program. 1.3 Steps to Create New Program in gedit: Type the following program: // Program Example 1 // This program displays message "Welcome to UniMAP #include <stdio.h> int main() { printf("\nwelcome to UniMAP\n"); return 0; } Once finished, save the program file or also known as the source file. 1.4 Steps to Save the Source File: Go to File menu, select Save as option Save the file as welcome.c. Type welcome.c in the box besides the Name location. OR if you want to save in a specified folder, select the folder in the save as dialog box. (e.g. /home/student/foldername), double click the folder icon and then type welcome.c in the box besides the Name location. Click Save button. Notes : The filename must be in one word with extension.c, for example Program.c or pgm_1.c. 1.5 Steps to Compile a Program: Click Applications icon > Accessories > Terminal Use the following commands to check the source file location: pwd - command to check the current directory ls - to list down the files in the current directory. cd directory - to change directory If you have found your file, use the command gcc to compile the program welcome.c gcc welcome.c 2

3 Note: after compiling using the above command, if there is no error a default binary file, a.out is created. This is an executable file You can also compile the program and specify the output file (the executable file) name together with the compile command. This is to specify or named your binary file related to your program. gcc -o welcome.out welcome.c OR gcc welcome.c -o welcome.out Note: use the o parameter to specify the output file, followed the filename that you want to specify. 1.6 Steps to Execute or Run the Program In the Terminal window, at the command prompt, run the binary file To run the default output (or binary) file, type:./a.out Note: the./ to specify the binary file is in the current directory. OR To run the specific output (or binary) file, type:./welcome.out When you run the file, the output should be: Welcome to UniMAP CONGRATULATIONS!!!! You are now able to write and run your first program successfully. 3

4 2. TASKS Now you have learned to compile a simple C program, try to answer the following questions: 2.1 True or False: a. In general, C statement is case sensitive Ans: b. The name of the primary function of a C program must be main Ans: c. main ( ) { } is a complete and correct C program. Ans: 2.2 Find error(s), if any, in each statement: a. void main (void); b. printf ( Do we need parentheses here? ); c. Printf( Is there any wrong here? ); d. printf( Where do we need a blank space ) 2.3 Type, compile and run this program, correct any error(s) you may find and rewrite the program. main( ) {printf ( There is no class tomorrow ); } 2.4 Determine and correct any error(s) you may find in the following command. ma in() PRINTF *, ( What is wrong? ); 4

5 2.5 Type the following program. #include <stdio.h> void main (void) { int da; float fb; da = 2; fb = 3.0; printf( Learning Basic Structure of C Language ); printf( da + fb = %f, da+fb); } a. Compile the above program and write down the comment given on the screen after compiling. b. Compile the above program to specify the output (binary) to a filename basic.out and then run the output file. Write the command that you use to complete the above instruction c. Write down the output of the program. d. Format the floating number into 8 numbers and 2 floating point. Write down the formatting format you use. e. Correct the program so that the output looks presentable. Describe the changes you have done and the output of the program. i. Write down the changes done to the program: 5

6 ii. What is the output of the program? f. Change the first void to int, then compile the program. Write down any message after compiling. g. Explain the program in your own word and describe the command from top until end of the program. 6