/* decale.c */

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <errno.h>
#include "decale.h"
#include "code.h"

FILE *source, *dest;
int para;

void decalecar (char lettre)
{
  if (isalpha(lettre)) 
    {
      if ((islower(lettre) && lettre <= 'z' - para) ||
	  (isupper(lettre) && lettre <= 'Z' - para)) 
	{
	  fputc ( lettre + para , dest);
	}
      else /* cas particulier pour les (para) 1ers car */
	{ 
	  fputc ( lettre + para - 26 , dest);
	}
    }
  else 
    {
      fputc (lettre, dest);
    }
}

void decalefich(void)
{
  int carcour;
  carcour = fgetc(source);
  while (carcour != EOF)
    {
      decalecar (carcour);
      carcour = fgetc(source);
    }
}

int main (int argc, char **argv)
{
  gestion_parametres (argc, argv);
  decalefich ();
  fclose (source);
  fclose (dest);
  return 0;
}