/* move the cursor of offset positions. */
void
seek_ifile(file_desc_t *fd, int offset)
{
unsigned int old_pos = fd->fds_pos;
unsigned int fbloc, vbloc;
/* update the position */
fd->fds_pos += offset;
/* does the seek imply a jump in another bloc? */
if (bloc_of_pos(fd->fds_pos) != bloc_of_pos(old_pos)) {
/* flush */
flush_ifile(fd);
/* the bloc index of the new buffer */
fbloc = bloc_of_pos(fd->fds_pos);
vbloc = vbloc_of_fbloc(fd->fds_inumber, fbloc, FALSE);
if (! vbloc)
/* the bloc #0 is full of zeros */
memset(fd->fds_buf, 0, BLOC_SIZE);
else
/* load the bloc */
read_bloc(current_volume, vbloc, fd->fds_buf);
}
}
int main(int argc, char**argv){
unsigned int i;
unsigned int inumber = 0;
file_desc_t fd;
/* gestion des arguments */
if(argc!=3){
usage();
exit(EXIT_SUCCESS);
}
inumber = atoi(argv[1]);
if(inumber==0){
usage();
exit(EXIT_FAILURE);
}
/* init hardware */
if(!init_hardware(HW_CONFIG)) {
fprintf(stderr, "Initialization error\n");
exit(EXIT_FAILURE);
}
/* Interreupt handlers */
for(i=0; i<NB_EMPTY_FUNCTION; i++)
IRQVECTOR[i] = empty_it;
/* Allows all IT */
_mask(1);
/* chargement du mbr */
if(!load_mbr()){
fprintf(stderr, "Erreur lors du chargement du Master Boot Record.\n");
exit(EXIT_FAILURE);
}
/* initialise le super du premier volume */
init_super(CURRENT_VOLUME);
/* charge le super du premier volume dans la variable globale */
load_super(CURRENT_VOLUME);
/* manipulation du fichier */
if(open_ifile(&fd, inumber) == RETURN_FAILURE){
fprintf(stderr, "Erreur lors de l'ouverture du fichier\n");
exit(EXIT_FAILURE);
}
if(write_ifile(&fd, argv[2], strlen(argv[2])+1) == RETURN_FAILURE){
fprintf(stderr, "Erreur lors de l'ecriture dans le fichier\n");
exit(EXIT_FAILURE);
}
flush_ifile(&fd);
close_ifile(&fd);
exit(EXIT_SUCCESS);
}
void
close_ifile(file_desc_t *fd)
{
struct inode_s inode;
/* if the buffer is dirty, flush the file */
flush_ifile(fd);
/* update the inode information (size) */
read_inode(fd->fds_inumber, &inode);
inode.ind_size = fd->fds_size;
write_inode(fd->fds_inumber, &inode);
}