Hello world !

• Open a terminal
• Create your file by writing the following command

vim ex1.c

• Enter insertion mode by pressing Insert
• Write the lines below

#include <stdio.h>
 
int main(){
 
	printf("Hello world !\n");
 
	return 0 ;
}

• Then press Esc key
• Write :wq
• Compile your code with the following line

gcc -Wall ex1.c -o ex1

• Then run your programm by typing “./ex1” in the terminal

• Open a terminal
• Copy the content of the first exercice to the second by writing the following command

cp ex1.c ex2.c

• Open ex2.c with vim

vim ex2.c

• Edit your file so it looks like this :

#include <stdio.h>
 
int main(){
#ifdef DEBUG
	printf("Hello world !\n");
#endif
 
	return 0 ;
}

• Compile your code with gcc

gcc -Wall ex2.c -o ex2

• Run it with “./ex2”
• Nothing should happen, it's normal because you didn't tell the compiler to use preprocessor parts. Which are defined by the #ifdef #endif quotes
• now recompile your program with the following line

gcc -Wall -DDEBUG ex2.c -o ex2

• Run it again
• Hello world !

• Open a terminal
• Create your file by writing the following command

vim ex3.c

• Enter insertion mode by pressing Insert
• Write the lines below

#include<stdio.h>
 
int main(int argc, char** argv)
{
    char nom[14];
    printf("Salut\nComment t'appelles-tu ?\n");
    scanf("%s", nom);
    printf("Salut %s\n", nom);
 
    return 0;
}

• Then press Esc key
• Write :wq
• Compile your code with the following line

gcc -Wall ex3.c -o ex3

• Then run your programm by typing “./ex3” in the terminal

• Open a terminal
• Create your file by writing the following command

vim ex4.c

• Enter insertion mode by pressing Insert
• Write the lines below

#include<stdio.h>
 
int main(int argc, char** argv)
{
    int nbrMax;
    int i = 1;
    printf("Salut\nEntre un nombre\n");
    scanf("%d", &nbrMax);
    printf("Affichage de nombres de 1 à %d\n", nbrMax);
    for(i=1;i<=nbrMax;i++)
    {
        printf("%d\n", i);
    }
 
    return 0;
}

• Then press Esc key
• Write :wq
• Compile your code with the following line

gcc -Wall ex4.c -o ex4

• Then run your programm by typing “./ex4” in the terminal

• Open a terminal
• Create your file by writing the following command

vim ex5.c

• Enter insertion mode by pressing Insert
• Write the lines below

#include<stdio.h>
 
int main(int argc, char** argv)
{
    int i = 1;
    int j = 1;
    int nbrMax = 10;
    for(i=1;i<=nbrMax;i++)
    {
        for(j=1;j<=nbrMax;j++)
        {
            printf("%d\t", i*j);
        }
        printf("\n");
    }
 
    return 0;
}

• Then press Esc key
• Write :wq
• Compile your code with the following line

gcc -Wall ex5.c -o ex5

• Then run your programm by typing “./ex5” in the terminal