Code:
#include <stdio.h>#include <stdlib.h>
#include <string.h>
void crypter();
void decrypter();
int main()
{
int choix;
do
{
printf("Bienvenue\n");
printf("Appuyez sur 1 pour crypter un fichier\n");
printf("Appuyez sur 2 pour decrypter un fichier\n");
scanf("%d", &choix);
switch(choix)
{
case 1: crypter();
break;
case 2: decrypter();
break;
default: printf("Erreur le programme va s'arreter");
break;
}
} while(choix != 3);
return 0;
}
void crypter()
{
char alphabet[26] = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
char alphabetcap[26] = {'A','B','C','D','E','F','G','H','I','G','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
int cle,i = 0, j;
char temp1;
char temp,newTexte[1000];
char texte[1000];
FILE *fp;
memset(newTexte,0,strlen(newTexte));
printf("Inserez un nombre: ");
scanf("%d", &cle);
printf("Inserez un texte: ");
scanf("%c",&temp);
fgets(texte,1000,stdin);
for (i; i < 1000 ; i++)
{
for (j = 0; j < 26; j++)
{
if (texte[i] == alphabet[j])
{
temp1 = texte[i] + j;
newTexte[i] = temp1;
}
}
texte[i] = newTexte[i];
}
fp = fopen("test.txt", "w");
fwrite(&texte, sizeof(texte), 1, fp);
fclose(fp);
}
void decrypter()
{
char alphabet[26] = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
char alphabetcap[26] = {'A','B','C','D','E','F','G','H','I','G','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
int i, j, cle;
char texte[1000],ch, temp;
char newTexte[1000];
FILE *fp;
fp = fopen("test.txt", "r");
printf("Inserez un nombre: ");
scanf("%d", &cle);
while (fgets(texte, sizeof(texte), fp)!=NULL)
{
for (i = 0; i < 1000 ; i++)
{
ch = texte[i];
for(j = 0; j < 26; j++)
{
if (ch == alphabet[j])
{
temp = (j - cle);
texte[i] = temp;
}
}
}
printf("%c", texte);
}
}