git.sur5r.net Git - cc65/blob - libsrc/cbm/cbm_dir.c

   1 /* This is a very simplified version of the POSIX opendir(),  */
   2 /* readdir(), and closedir() -- for Commodore computers.      */
   3 /* Created by Josef Soucek, 2003.  E-mail: josef.soucek@ct.cz */
   4
   5 /* 2003-01-21 -- Version 0.1 */
   6 /* 2009-10-10 -- Version 0.3 */
   7 /* 2011-04-07 -- Version 0.4, groepaz */
   8 /* 2011-04-14 -- Version 0.5, Greg King */
   9
  10 /* Tested with floppy-drive and IDE64 devices.        */
  11 /* Not tested with messed (buggy) directory listings. */
  12 /* Limits filenames to 16 chars. (VICE supports more  */
  13 /* in directory listings).                            */
  14
  15
  16 #include <cbm.h>
  17 #include <errno.h>
  18
  19
  20
  21 /* Opens directory listing.
  22 ** Returns 0 if openning directory was successful;
  23 ** otherwise, an error-code corresponding to cbm_open().
  24 */
  25 unsigned char __fastcall__ cbm_opendir (unsigned char lfn, unsigned char device)
  26 {
  27     if (cbm_open (lfn, device, CBM_READ, "$") == 0) {
  28         if ((_oserror = cbm_k_chkin (lfn)) == 0) {
  29             /* Ignore start address */
  30             cbm_k_basin();
  31             cbm_k_basin();
  32             cbm_k_clrch();
  33             if (cbm_k_readst()) {
  34                 cbm_close(lfn);
  35                 _oserror = 4;           /* directory cannot be read */
  36             }
  37         }
  38     }
  39     return _oserror;
  40 }
  41
  42
  43
  44 /* Reads one directory line into cbm_dirent structure.
  45 ** Returns 0 if reading directory-line was successful.
  46 ** Returns non-zero if reading directory failed, or no more file-names to read.
  47 ** Returns 2 on last line.  Then, l_dirent->size = the number of "blocks free."
  48 */
  49 unsigned char __fastcall__ cbm_readdir (unsigned char lfn, register struct cbm_dirent* l_dirent)
  50 {
  51     unsigned char byte, i = 0;
  52     unsigned char is_header = 0;
  53     unsigned char rv = 1;
  54     static const unsigned char types[] = {
  55         CBM_T_CBM,   CBM_T_DEL,   CBM_T_OTHER, CBM_T_OTHER, /* c d e f */
  56         CBM_T_OTHER, CBM_T_OTHER, CBM_T_OTHER, CBM_T_OTHER, /* g h i j */
  57         CBM_T_OTHER, CBM_T_LNK,   CBM_T_OTHER, CBM_T_OTHER, /* k l m n */
  58         CBM_T_OTHER, CBM_T_PRG,   CBM_T_OTHER, CBM_T_REL,   /* o p q r */
  59         CBM_T_SEQ,   CBM_T_OTHER, CBM_T_USR,   CBM_T_VRP    /* s t u v */
  60     };
  61
  62     if (!cbm_k_chkin(lfn)) {
  63         if (!cbm_k_readst()) {
  64             /* skip 2 bytes, next-BASIC-line pointer */
  65             cbm_k_basin();
  66             cbm_k_basin();
  67
  68             /* File-size or drive/partition number */
  69             l_dirent->size = cbm_k_basin() | (cbm_k_basin() << 8);
  70
  71             byte = cbm_k_basin();
  72             switch (byte) {
  73
  74                 /* "B" BLOCKS FREE. */
  75               case 'b':
  76                 /* Read until end; careless callers might call us again. */
  77                 while (!cbm_k_readst()) {
  78                     cbm_k_basin();
  79                 }
  80                 rv = 2; /* EOF */
  81                 goto ret_val;
  82
  83                 /* Reverse-text shows when this is the directory header. */
  84               case 0x12:  /* RVS_ON */
  85                 is_header = 1;
  86             }
  87
  88             while (byte != '\"') {
  89                 /* prevent endless loop */
  90                 if (cbm_k_readst()) {
  91                     rv = 3;
  92                     goto ret_val;
  93                 }
  94                 byte = cbm_k_basin();
  95             }
  96
  97             while ((byte = cbm_k_basin()) != '\"') {
  98                 /* prevent endless loop */
  99                 if (cbm_k_readst()) {
 100                     rv = 4;
 101                     goto ret_val;
 102                 }
 103
 104                 if (i < sizeof (l_dirent->name) - 1) {
 105                     l_dirent->name[i] = byte;
 106                     ++i;
 107                 }
 108             }
 109             l_dirent->name[i] = '\0';
 110
 111             if (is_header) {
 112                 l_dirent->type = CBM_T_HEADER;
 113
 114                 /* Get the disk-format code. */
 115                 i = 6;
 116                 do {
 117                     l_dirent->access = byte = cbm_k_basin();
 118                 } while (--i != 0);
 119
 120             } else {
 121                 /* Go to the file-type column. */
 122                 while ((byte = cbm_k_basin()) == ' ') {
 123                     /* prevent endless loop */
 124                     if (cbm_k_readst()) {
 125                         rv = 5;
 126                         goto ret_val;
 127                     }
 128                 }
 129
 130                 l_dirent->access = CBM_A_RW;
 131
 132                 /* "Splat" files shouldn't be read. */
 133                 if (byte == '*') {
 134                     l_dirent->access = CBM_A_WO;
 135                     byte = cbm_k_basin();
 136                 }
 137
 138                 if (byte >= 'c' && byte < 'c' + sizeof types) {
 139                     l_dirent->type = types[byte - 'c'];
 140                 } else {
 141                     l_dirent->type = CBM_T_OTHER;
 142                 }
 143
 144                 /* Notice whether it's a directory or a deleted file. */
 145                 if (cbm_k_basin() == 'i' && byte == 'd') {
 146                     l_dirent->type = CBM_T_DIR;
 147                 }
 148                 cbm_k_basin();
 149
 150                 /* Locked files shouldn't be written. */
 151                 if ((byte = cbm_k_basin()) == '<') {
 152                     l_dirent->access = (l_dirent->access == CBM_A_WO)
 153                         ? 0 : CBM_A_RO;
 154                 }
 155             }
 156
 157             /* Read to the end of the line. */
 158             while (byte != 0) {
 159                 /* prevent endless loop */
 160                 if (cbm_k_readst()) {
 161                     rv = 6;
 162                     goto ret_val;
 163                 }
 164                 byte = cbm_k_basin();
 165             }
 166
 167             rv = 0;
 168             goto ret_val;
 169         }
 170     }
 171
 172 ret_val:
 173     cbm_k_clrch();
 174     return rv;
 175 }
 176
 177
 178
 179 void __fastcall__ cbm_closedir (unsigned char lfn)
 180 {
 181     cbm_close(lfn);
 182 }
 183
 184