INFORMATION D'UN LECTEUR

#include <stdio.h>
#include <dos.h>
#include <ctype.h>
#include <conio.h>
#include <stdlib.h>

void main()
{
 struct diskfree_t free;
 char drive;
 unsigned int drive_number;
 long int freespace,totspace;
 float perspace;

 printf("\nEntrer une lettre de lecteur : ");
 scanf("%c",&drive);
 switch (tolower(drive))
 {
  case 'a' : drive_number=1;
				 goto end;
  case 'b' : drive_number=2;
				 goto end;
  case 'c' : drive_number=3;
				 goto end;
  case 'd' : drive_number=4;
				 goto end;
  case 'e' : drive_number=5;
				 goto end;
  case 'f' : drive_number=6;
				 goto end;
  case 'g' : drive_number=7;
				 goto end;
  case 'h' : drive_number=8;
				 goto end;
  default  : drive_number=0;
 }
 end:

 if((_dos_getdiskfree(drive_number,&free))!=0)
 {
  clrscr();
  printf("\nImpossible de lire le lecteur\n");
  exit(1);
 }

 freespace = (long)free.avail_clusters
			  * (long)free.sectors_per_cluster
			  * (long)free.bytes_per_sector;
 totspace = (long)free.total_clusters
			 * (long)free.sectors_per_cluster
			 * (long)free.bytes_per_sector;
 perspace = (float)freespace/(float)totspace*100;

 printf("\n****************************************");
 printf("\nINFORMATION CLUSTER \n");
 printf("\nNombre total de clusters disponible   : %ld",(long)free.total_clusters);
 printf("\nNombre de clusters libre  : %ld",(long)free.avail_clusters);
 printf("\n****************************************");
 printf("\nINFORMATION DU LECTEUR\n");
 printf("\nSecteurs Par Cluster       : %ld",(long)free.sectors_per_cluster);
 printf("\nOctets Par Secteur          : %ld",(long)free.bytes_per_sector);
 printf("\n****************************************");
 printf("\nESPACE LIBRE\n");
 printf("\nESPACE LIBRE(Octets) : %ld",freespace);
 printf("\nCAPACITE DU LECTEUR(Bytes): %ld\n",totspace);
 printf("\nESPACE LIBRE(Pourcentage)     : %4.3f %",perspace);

}

int GetDiskID(char Drive)
{
}