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programming:c:hello_world

Hello world !

Exercice 1 : printf

  • 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

Exercice 2

  • 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 !

Exercice 3 : scanf

  • 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

Exercice 4 : for

  • 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

Exercice 5 : for in for

  • 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
programming/c/hello_world.txt · Last modified: 2014/12/11 16:22 by czuber