isoread.c

minix软件源代码

  char tmp_path[MAX_PATH_LENGTH];
  int i,j, path_length;
  long block;
  int nr_of_blocks;
  int offset = 0; 

  
  /* Save block number and nr of blocks of current dir entry because 
   * list_dir changes dir_ptr 
   */
  block = iso_733(dir_ptr->first_block) + iso_711(dir_ptr->ext_attr_length);
  nr_of_blocks = (int) (iso_733(dir_ptr->size) >> BLOCK_SHIFT);

  /* Add a trailing / to path if necessary */
  path_length = strlen(path);
  if (path[path_length-1] != '/')
  {
    path[path_length++] = '/';
    path[path_length] = '\0';
  }

  /* Print current path of directory, and list contents of directory */
  fprintf(STDOUT,"directory %s:\n\n", path);
  list_dir(dir_ptr);
  fprintf(STDOUT,"\n\n");
  
  for (j=0; j < nr_of_blocks; j++) 
  {
    read_device(block*BLOCK_SIZE, BLOCK_SIZE, Buffer);
    block++;

    /* Save buffer, because the next recursive call destroys 
     * the global Buffer 
     */
    for (i=0; i < BLOCK_SIZE; i++) tmp_buffer[i] = Buffer[i];

    dir_ptr = (struct dir_entry *) tmp_buffer;

    /* Search this dir entry for directories */
    offset = 0;
    while (iso_711(dir_ptr->length) != 0 && offset < BLOCK_SIZE)
    {
      /* Is current file a directory and not the . or .. entries */
      if (IS_DIR(dir_ptr)  && !IS_DOT(dir_ptr) && !IS_DOT_DOT(dir_ptr))
      {
        /* setup path for next recursive call */
        for (i=0; i<path_length; i++) tmp_path[i] = path[i]; 
        for (i=0;i<iso_711(dir_ptr->name_length) && dir_ptr->name[i] != ';';i++)
          tmp_path[i+path_length] = LOWER_CASE(dir_ptr->name[i]);
        tmp_path[i+path_length] = '/';
        tmp_path[i+1+path_length] = '\0';
  
        /* Read block of directory we found */
        block = iso_733(dir_ptr->first_block);
        read_device(block*BLOCK_SIZE, BLOCK_SIZE, Buffer);
  
        /* And start all over again with this entry */
        recurse_dir(tmp_path, (struct dir_entry *) Buffer);
      }

      /* Go to the next file in this directory */
      offset += iso_711(dir_ptr->length);
      dir_ptr = (struct dir_entry *) (tmp_buffer + offset);
    }
  }
}
    

void list_dir(dir_ptr)
struct dir_entry *dir_ptr;
{
  /* List all entries in a directory */

  long block;
  int nr_of_blocks;
  int i,j;
  int offset = 0;
  char name[NR_OF_CHARS+NR_OF_BLANKS+1];
  int name_len;
  int column = 0;
  int skip = 0;

  /* Get first block of directory */
  block = iso_733(dir_ptr->first_block) + iso_711(dir_ptr->ext_attr_length);
  nr_of_blocks = (int) (iso_733(dir_ptr->size) >> BLOCK_SHIFT);

  /* Read all directory blocks and display their contents */
  for (j=0; j < nr_of_blocks; j++) 
  {
    read_device(block*BLOCK_SIZE, BLOCK_SIZE, Buffer);
    block++;

    dir_ptr = (struct dir_entry *) (Buffer);
    offset = 0;
    while (iso_711(dir_ptr->length) != 0 && offset < BLOCK_SIZE)
    {
      name_len = 0;
      if (IS_DOT(dir_ptr))
      {
        name[name_len++] =  '.';
        if (!Verbose) skip = 1;
      }
      else
      {
        if (IS_DOT_DOT(dir_ptr))
        { 
          name[name_len++] =  '.';
          name[name_len++] =  '.';
          if (!Verbose) skip = 1;
        }
        else
        {
          for (i=0; i<iso_711(dir_ptr->name_length) &&
                    i<NR_OF_CHARS; i++) 
          {
            if (dir_ptr->name[i] == ';') break;
            name[name_len++] = LOWER_CASE(dir_ptr->name[i]);
          }
          if (IS_DIR(dir_ptr)) name[name_len++] = '/';
        }
      }
      if (!skip)
      {
        if (Verbose)
        {
          fprintf (STDOUT, "%8ld ",  iso_733(dir_ptr->size));
          print_dir_date(dir_ptr->date);
          fprintf (STDOUT, " ");
        }
        for(i=name_len; i<(NR_OF_CHARS+NR_OF_BLANKS); i++) name[i] = ' ';
        name[NR_OF_CHARS+NR_OF_BLANKS] = '\0';
        fprintf(STDOUT, "%s", name);
        if (!Verbose)
        {
          column++;
          if (column >= NR_OF_COLS) 
          {
            column = 0;
            fprintf(STDOUT,"\n");
          }
        }
        else fprintf(STDOUT,"\n");
      }
      skip = 0;
      offset += iso_711(dir_ptr->length);
      dir_ptr = (struct dir_entry *) (Buffer+offset);
    }
  }
  if (!Verbose && column) fprintf(STDOUT,"\n");
}


void print_dir_date(date)
char *date;
{
  /* Print date in a directory entry */

  int i,m;

  m = iso_711(&date[1]) - 1;
  for (i = 0;i<3;i++) fprintf(STDOUT,"%c",months[m*3+i]);

  fprintf (STDOUT, " %02d 19%02d %02d:%02d:%02d",
           date[2],
           date[0],
           date[3],
           date[4],
           date[5]);
}


void list_file(dir_ptr)
struct dir_entry *dir_ptr;
{
  /* List contents of a file */

  int i;
  long block;
  long size;

  block = iso_733(dir_ptr->first_block);
  size = iso_733(dir_ptr->size);

  while (size > 0)
  {
    read_device(block*BLOCK_SIZE, BLOCK_SIZE, Buffer);
    for (i=0; ((i < size) && (i < BLOCK_SIZE)); i++)
      fprintf(STDOUT, "%c", Buffer[i]);
    size-= BLOCK_SIZE;
    block++;
  }
}


void print_date(date)
char *date;
{
  /* Print the date in a volume descriptor */

  fprintf (STDOUT, "%c%c-%c%c-%c%c%c%c %c%c:%c%c:%c%c",
           date[4],
           date[5],
           date[6],
           date[7],
           date[0],
           date[1],
           date[2],
           date[3],
           date[8],
           date[9],
           date[10],
           date[11],
           date[12],
           date[13]);
}

void iso_info(vol_desc)
struct iso9660_descriptor *vol_desc;
{
  int i;

  fprintf (STDOUT, "Format: ISO9660 \n");
  fprintf (STDOUT, "System id: ");
  for (i=0; i< sizeof(vol_desc->system_id); i++) 
    fprintf(STDOUT, "%c", vol_desc->system_id[i]);
  fprintf (STDOUT, "\n");
  fprintf (STDOUT, "Volume id: ");
  for (i=0; i< sizeof(vol_desc->volume_id); i++) 
    fprintf(STDOUT, "%c", vol_desc->volume_id[i]);
  fprintf (STDOUT, "\n");
  fprintf (STDOUT, "Volume size: %ld Kb\n", iso_733(vol_desc->volume_size)*2);
  fprintf (STDOUT, "Block size: %d bytes \n", iso_723(vol_desc->block_size));
  fprintf (STDOUT, "Creation date: ");
  print_date(vol_desc->creation_date); 
  fprintf(STDOUT, "\n");
  fprintf (STDOUT, "Modification date: ");
  print_date(vol_desc->mod_date); 
  fprintf (STDOUT, "\n");
  fprintf (STDOUT, "Expiration date: ");
  print_date(vol_desc->exp_date); 
  fprintf (STDOUT, "\n");
  fprintf (STDOUT, "Effective date: ");
  print_date(vol_desc->eff_date); 
  fprintf (STDOUT, "\n");
}


void hs_info(vol_desc)
struct high_sierra_descriptor *vol_desc;
{
  int i;

  fprintf (STDOUT, "Format: HIGH SIERRA \n");
  fprintf (STDOUT, "System id: ");
  for (i=0; i< sizeof(vol_desc->system_id); i++) 
    fprintf(STDOUT, "%c", vol_desc->system_id[i]);
  fprintf (STDOUT, "\n");
  fprintf (STDOUT, "Volume id: ");
  for (i=0; i< sizeof(vol_desc->volume_id); i++) 
    fprintf(STDOUT, "%c", vol_desc->volume_id[i]);
  fprintf (STDOUT, "\n");
  fprintf (STDOUT, "Volume size: %ld Kb\n", (iso_733(vol_desc->volume_size)*2));
  fprintf (STDOUT, "Block size: %d bytes \n", iso_723(vol_desc->block_size));
}
  

int valid_fs()               
{

  int i;

  /* search for a volume descriptor */
  for (i=16; i<100; i++)
  {
  
    read_device((long)(i)*BLOCK_SIZE, BLOCK_SIZE, Buffer);

    Iso_Vol_Desc = (struct iso9660_descriptor *) Buffer; 
    Hs_Vol_Desc = (struct high_sierra_descriptor *) Buffer; 
    
    if (strncmp(Iso_Vol_Desc->id, ISO9660_ID, sizeof Iso_Vol_Desc->id) == 0)
    {
      /* iso_info(Iso_Vol_Desc); */
      Iso9660 = 1;
      break;  
    }

    if (strncmp(Hs_Vol_Desc->id, HIGH_SIERRA_ID, sizeof Hs_Vol_Desc->id) == 0)
    {
      /* hs_info(Hs_Vol_Desc); */
      High_Sierra = 1; 
      break;  
    }
  }

  if (i >= 100) return 0;
  return 1;
}


void read_device(offset, nr_of_bytes, buffer)
long offset;
int nr_of_bytes;
char *buffer;
{
  int bytes_read;

  if (lseek(Device, offset, SEEK_SET) < 0L) 
  {
	fflush (stdout);
	fprintf (STDERR, "seek error\n");
	exit(1);
  }

  bytes_read = read(Device, buffer, nr_of_bytes);
  if (bytes_read != nr_of_bytes) 
  {
  	fprintf (STDERR, "read error\n");
  	exit (1);
  }
}


/* The ISO9660 functions */

int iso_711 (c)
char *c;
{
  return (*c & 0xff);
}


int iso_712 (c)
char *c;
{
  int n;
	
  n = *c;
  if (n & 0x80) n |= 0xffffff00;
  return n;
}

int iso_721 (c)
char *c;
{
  return ((c[0] & 0xff) | ((c[1] & 0xff) << 8));
}

int iso_722 (c)
char *c;
{
  return (((c[0] & 0xff) << 8) | (c[1] & 0xff));
}

int iso_723 (c)
char *c;
{
  if (c[0] != c[3] || c[1] != c[2]) 
  {
    fprintf (STDERR, "Invalid ISO 7.2.3 number\n");
    exit (1);
  }
  return (iso_721 (c));
}

long iso_731 (c)
char *c;
{
  return ((long)(c[0] & 0xff)
       | ((long)(c[1] & 0xff) << 8)
       | ((long)(c[2] & 0xff) << 16)
       | ((long)(c[3] & 0xff) << 24));
}


long iso_732 (c)
char *c;
{
  return (((long)(c[0] & 0xff) << 24)
        | (((long)c[1] & 0xff) << 16)
        | (((long)c[2] & 0xff) << 8)
        | ((long)c[3] & 0xff));
}

long iso_733 (c)
char *c;
{
int i;

  for (i = 0; i < 4; i++) 
  {
    if (c[i] != c[7-i]) 
    {
      fprintf (STDERR, "Invalid ISO 7.3.3 number\n");
      exit (1);
    }
  }
  return (iso_731(c));
}