reactos/lib/crtdll/dirent/dirent.c

   1 /*
   2  * dirent.c
   3  *
   4  * Derived from DIRLIB.C by Matt J. Weinstein
   5  * This note appears in the DIRLIB.H
   6  * DIRLIB.H by M. J. Weinstein   Released to public domain 1-Jan-89
   7  *
   8  * Updated by Jeremy Bettis <jeremy@hksys.com>
   9  * Significantly revised and rewinddir, seekdir and telldir added by Colin
  10  * Peters <colin@fu.is.saga-u.ac.jp>
  11  *
  12  * $Revision: 1.3 $
  13  * $Author$
  14  * $Date$
  15  *
  16  */
  17
  18 #include <msvcrt/stdlib.h>
  19 /* #include <msvcrt/ctype.h> */
  20 #include <msvcrt/errno.h>
  21 #include <msvcrt/string.h>
  22 #include <msvcrt/dir.h>
  23 #include <msvcrt/direct.h>
  24 #include <msvcrt/sys/stat.h>
  25
  26 #include <msvcrt/dirent.h>
  27
  28 #define SUFFIX  "*"
  29 #define SLASH   "\\"
  30 #define streq(a,b)      (strcmp(a,b)==0)
  31
  32 /*
  33  * opendir
  34  *
  35  * Returns a pointer to a DIR structure appropriately filled in to begin
  36  * searching a directory.
  37  */
  38 DIR*
  39 opendir(const char* szPath)
  40 {
  41         DIR* nd;
  42         struct stat statDir;
  43
  44         errno = 0;
  45
  46         if (!szPath)
  47         {
  48                 errno = EFAULT;
  49                 return (DIR*) 0;
  50         }
  51
  52         if (szPath[0] == '\0')
  53         {
  54                 errno = ENOTDIR;
  55                 return (DIR*) 0;
  56         }
  57
  58         /* Attempt to determine if the given path really is a directory. */
  59         if (_stat (szPath, &statDir))
  60         {
  61                 /* Error, stat should have set an error value. */
  62                 return (DIR*) 0;
  63         }
  64
  65         if (!S_ISDIR(statDir.st_mode))
  66         {
  67                 /* Error, stat reports not a directory. */
  68                 errno = ENOTDIR;
  69                 return (DIR*) 0;
  70         }
  71
  72         /* Allocate enough space to store DIR structure and the complete
  73          * directory path given. */
  74         nd = (DIR*) malloc (sizeof(DIR) + strlen(szPath) + strlen(SLASH) +
  75                 strlen(SUFFIX));
  76
  77         if (!nd)
  78         {
  79                 /* Error, out of memory. */
  80                 errno = ENOMEM;
  81                 return (DIR*) 0;
  82         }
  83
  84         /* Create the search expression. */
  85         strcpy(nd->dd_name, szPath);
  86
  87         /* Add on a slash if the path does not end with one. */
  88         if (nd->dd_name[0] != '\0' &&
  89             nd->dd_name[strlen(nd->dd_name)-1] != '/' &&
  90             nd->dd_name[strlen(nd->dd_name)-1] != '\\')
  91         {
  92                 strcat(nd->dd_name, SLASH);
  93         }
  94
  95         /* Add on the search pattern */
  96         strcat(nd->dd_name, SUFFIX);
  97
  98         /* Initialize handle to -1 so that a premature closedir doesn't try
  99          * to call _findclose on it. */
 100         nd->dd_handle = -1;
 101
 102         /* Initialize the status. */
 103         nd->dd_stat = 0;
 104
 105         /* Initialize the dirent structure. ino and reclen are invalid under
 106          * Win32, and name simply points at the appropriate part of the
 107          * findfirst_t structure. */
 108         nd->dd_dir.d_ino = 0;
 109         nd->dd_dir.d_reclen = 0;
 110         nd->dd_dir.d_namlen = 0;
 111         nd->dd_dir.d_name = nd->dd_dta.name;
 112
 113         return nd;
 114 }
 115
 116
 117 /*
 118  * readdir
 119  *
 120  * Return a pointer to a dirent structure filled with the information on the
 121  * next entry in the directory.
 122  */
 123 struct dirent *
 124 readdir( DIR *dirp )
 125 {
 126         errno = 0;
 127
 128         /* Check for valid DIR struct. */
 129         if (!dirp)
 130         {
 131                 errno = EFAULT;
 132                 return (struct dirent*) 0;
 133         }
 134
 135         if (dirp->dd_dir.d_name != dirp->dd_dta.name)
 136         {
 137                 /* The structure does not seem to be set up correctly. */
 138                 errno = EINVAL;
 139                 return (struct dirent*) 0;
 140         }
 141
 142         if (dirp->dd_stat < 0)
 143         {
 144                 /* We have already returned all files in the directory
 145                  * (or the structure has an invalid dd_stat). */
 146                 return (struct dirent *) 0;
 147         }
 148         else if (dirp->dd_stat == 0)
 149         {
 150                 /* We haven't started the search yet. */
 151                 /* Start the search */
 152                 dirp->dd_handle = _findfirst(dirp->dd_name, &(dirp->dd_dta));
 153
 154                 if (dirp->dd_handle == -1)
 155                 {
 156                         /* Whoops! Seems there are no files in that
 157                          * directory. */
 158                         dirp->dd_stat = -1;
 159                 }
 160                 else
 161                 {
 162                         dirp->dd_stat = 1;
 163                 }
 164         }
 165         else
 166         {
 167                 /* Get the next search entry. */
 168                 if (_findnext(dirp->dd_handle, &(dirp->dd_dta)))
 169                 {
 170                         /* We are off the end or otherwise error. */
 171                         _findclose (dirp->dd_handle);
 172                         dirp->dd_handle = -1;
 173                         dirp->dd_stat = -1;
 174                 }
 175                 else
 176                 {
 177                         /* Update the status to indicate the correct
 178                          * number. */
 179                         dirp->dd_stat++;
 180                 }
 181         }
 182
 183         if (dirp->dd_stat > 0)
 184         {
 185                 /* Successfully got an entry. Everything about the file is
 186                  * already appropriately filled in except the length of the
 187                  * file name. */
 188                 dirp->dd_dir.d_namlen = strlen(dirp->dd_dir.d_name);
 189                 return &dirp->dd_dir;
 190         }
 191
 192         return (struct dirent*) 0;
 193 }
 194
 195
 196 /*
 197  * closedir
 198  *
 199  * Frees up resources allocated by opendir.
 200  */
 201 int
 202 closedir (DIR* dirp)
 203 {
 204         int     rc;
 205
 206         errno = 0;
 207         rc = 0;
 208
 209         if (!dirp)
 210         {
 211                 errno = EFAULT;
 212                 return -1;
 213         }
 214
 215         if (dirp->dd_handle != -1)
 216         {
 217                 rc = _findclose(dirp->dd_handle);
 218         }
 219
 220         /* Delete the dir structure. */
 221         free (dirp);
 222
 223         return rc;
 224 }
 225
 226 /*
 227  * rewinddir
 228  *
 229  * Return to the beginning of the directory "stream". We simply call findclose
 230  * and then reset things like an opendir.
 231  */
 232 void
 233 rewinddir (DIR* dirp)
 234 {
 235         errno = 0;
 236
 237         if (!dirp)
 238         {
 239                 errno = EFAULT;
 240                 return;
 241         }
 242
 243         if (dirp->dd_handle != -1)
 244         {
 245                 _findclose(dirp->dd_handle);
 246         }
 247
 248         dirp->dd_handle = -1;
 249         dirp->dd_stat = 0;
 250 }
 251
 252 /*
 253  * telldir
 254  *
 255  * Returns the "position" in the "directory stream" which can be used with
 256  * seekdir to go back to an old entry. We simply return the value in stat.
 257  */
 258 long
 259 telldir (DIR* dirp)
 260 {
 261         errno = 0;
 262
 263         if (!dirp)
 264         {
 265                 errno = EFAULT;
 266                 return -1;
 267         }
 268         return dirp->dd_stat;
 269 }
 270
 271 /*
 272  * seekdir
 273  *
 274  * Seek to an entry previously returned by telldir. We rewind the directory
 275  * and call readdir repeatedly until either dd_stat is the position number
 276  * or -1 (off the end). This is not perfect, in that the directory may
 277  * have changed while we weren't looking. But that is probably the case with
 278  * any such system.
 279  */
 280 void
 281 seekdir (DIR* dirp, long lPos)
 282 {
 283         errno = 0;
 284
 285         if (!dirp)
 286         {
 287                 errno = EFAULT;
 288                 return;
 289         }
 290
 291         if (lPos < -1)
 292         {
 293                 /* Seeking to an invalid position. */
 294                 errno = EINVAL;
 295                 return;
 296         }
 297         else if (lPos == -1)
 298         {
 299                 /* Seek past end. */
 300                 if (dirp->dd_handle != -1)
 301                 {
 302                         _findclose (dirp->dd_handle);
 303                 }
 304                 dirp->dd_handle = -1;
 305                 dirp->dd_stat = -1;
 306         }
 307         else
 308         {
 309                 /* Rewind and read forward to the appropriate index. */
 310                 rewinddir (dirp);
 311
 312                 while ((dirp->dd_stat < lPos) && readdir(dirp))
 313                         ;
 314         }
 315 }
 316