aplfw/volume/fat/fatvol_open.c

   1
   2 #include <string.h>
   3 #include "fatvol_local.h"
   4
   5
   6 HANDLE FatVol_Open(C_FATVOL *self, const char *pszPath, int iMode)
   7 {
   8         unsigned char ubBuf[32];
   9         FATVOL_UINT   uiCluster;
  10         HANDLE hDir;
  11         HANDLE hFile;
  12         char   szEntryName[8+3+1];
  13         int    iEntryNameLen;
  14         char   szName[8+3+1];
  15         int    iNameLen;
  16         int    iDirEntry;
  17         int    i, j;
  18
  19         /* ルートを基点にする */
  20         if ( *pszPath == '/' )
  21         {
  22                 pszPath++;
  23         }
  24
  25         /* ルートディレクトリを開く */
  26         hDir = FatVol_CreateFile(self, self->uiRootDirCluster, 0, 0, FILE_MODE_READ | FILE_MODE_WRITE);
  27
  28         for ( ; ; )
  29         {
  30                 /* 名前の部分を検索 */
  31                 for ( iNameLen = 0; pszPath[iNameLen] != '\0'; iNameLen++ )
  32                 {
  33                         if ( pszPath[iNameLen] == '/' )
  34                         {
  35                                 szName[iNameLen] = '\0';
  36                                 break;
  37                         }
  38
  39                         /* 大文字に変換 */
  40                         if ( pszPath[iNameLen] >= 'a' && pszPath[iNameLen] <= 'z' )
  41                         {
  42                                 szName[iNameLen] = pszPath[iNameLen] - ('a' - 'A');
  43                         }
  44                         else
  45                         {
  46                                 szName[iNameLen] = pszPath[iNameLen];
  47                         }
  48                 }
  49
  50                 /* ディレクトリエントリを検索 */
  51                 iDirEntry = -1;
  52                 for ( i = 0; File_Read(hDir, ubBuf, 32, 0) == 32; i++ )
  53                 {
  54                         /* 0なら打ち切り */
  55                         if ( ubBuf[0] == 0x00 )
  56                         {
  57                                 break;
  58                         }
  59
  60                         /* 名前部分取り出し */
  61                         iEntryNameLen = 0;
  62                         for ( j = 0; j < 8; j++ )
  63                         {
  64                                 if ( ubBuf[0+j] == ' ' || ubBuf[0+j] == '\0' )
  65                                 {
  66                                         break;
  67                                 }
  68                                 szEntryName[iEntryNameLen++] = (char)ubBuf[0+j];
  69                         }
  70                         szEntryName[iEntryNameLen++] = '.';
  71                         for ( j = 0; j < 3; j++ )
  72                         {
  73                                 if ( ubBuf[8+j] == ' ' || ubBuf[8+j] == '\0' )
  74                                 {
  75                                         break;
  76                                 }
  77                                 szEntryName[iEntryNameLen++] = (char)ubBuf[8+j];
  78                         }
  79                         szEntryName[iEntryNameLen++] = '\0';
  80                         if ( iEntryNameLen > 2 && szEntryName[iEntryNameLen-1] == '.' )
  81                         {
  82                                 szEntryName[--iEntryNameLen] = '\0';
  83                         }
  84
  85                         if ( strcmp(szEntryName, szName) == 0 )
  86                         {
  87                                 iDirEntry = i;
  88                                 break;
  89                         }
  90                 }
  91
  92                 /* 開始クラスタ取得 */
  93                 uiCluster = ubBuf[0x1a] + ubBuf[0x1b]*256;
  94                 if ( self->iFatType == FATVOL_TYPE_FAT32 )
  95                 {
  96                         uiCluster += ubBuf[0x14]*256*256 + ubBuf[0x15]*256*256*256;
  97                 }
  98
  99                 /* パス部分の解析が終わっていればここで抜ける */
 100                 if ( pszPath[iNameLen] == '\0' )
 101                 {
 102                         break;
 103                 }
 104
 105                 File_Close(hDir);
 106
 107                 /* サブディレクトリがなければエラー */
 108                 if ( iDirEntry < 0 || !(ubBuf[0x0b] & 0x10) )
 109                 {
 110                         return HANDLE_NULL;
 111                 }
 112
 113                 /* サブディレクトリを開く */
 114                 hDir = FatVol_CreateFile(self, uiCluster, 0, 0, FILE_MODE_READ | FILE_MODE_WRITE);
 115
 116                 pszPath += iNameLen;
 117         }
 118
 119         /* 既存ファイルがあれば */
 120         if ( iDirEntry >= 0 )
 121         {
 122                 hFile = FatVol_CreateFile(self, uiCluster, hDir, iDirEntry, iMode);
 123                 if ( hFile == HANDLE_NULL )
 124                 {
 125                         File_Close(hDir);
 126                 }
 127                 return hFile;
 128         }
 129
 130         File_Close(hDir);
 131         return HANDLE_NULL;
 132 }
 133
 134