uspace/lib/c/generic/dirent.c

   1 /*
   2  * Copyright (c) 2008 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup libc
  30  * @{
  31  */
  32 /** @file
  33  */
  34
  35 #include <vfs/vfs.h>
  36 #include <stdlib.h>
  37 #include <dirent.h>
  38 #include <stddef.h>
  39 #include <errno.h>
  40 #include <assert.h>
  41 #include <string.h>
  42
  43 struct __dirstream {
  44         int fd;
  45         struct dirent res;
  46         aoff64_t pos;
  47 };
  48
  49 /** Open directory.
  50  *
  51  * @param dirname Directory pathname
  52  *
  53  * @return Non-NULL pointer on success. On error returns @c NULL and sets errno.
  54  */
  55 DIR *opendir(const char *dirname)
  56 {
  57         DIR *dirp = malloc(sizeof(DIR));
  58         if (!dirp) {
  59                 errno = ENOMEM;
  60                 return NULL;
  61         }
  62
  63         int fd;
  64         errno_t rc = vfs_lookup(dirname, WALK_DIRECTORY, &fd);
  65         if (rc != EOK) {
  66                 free(dirp);
  67                 errno = rc;
  68                 return NULL;
  69         }
  70
  71         rc = vfs_open(fd, MODE_READ);
  72         if (rc != EOK) {
  73                 free(dirp);
  74                 vfs_put(fd);
  75                 errno = rc;
  76                 return NULL;
  77         }
  78
  79         dirp->fd = fd;
  80         dirp->pos = 0;
  81         return dirp;
  82 }
  83
  84 /** Read directory entry.
  85  *
  86  * @param dirp Open directory
  87  * @return Non-NULL pointer to directory entry on success. On error returns
  88  *         @c NULL and sets errno.
  89  */
  90 struct dirent *readdir(DIR *dirp)
  91 {
  92         errno_t rc;
  93         ssize_t len = 0;
  94
  95         rc = vfs_read_short(dirp->fd, dirp->pos, dirp->res.d_name,
  96             sizeof(dirp->res.d_name), &len);
  97         if (rc != EOK) {
  98                 errno = rc;
  99                 return NULL;
 100         }
 101
 102         assert(strnlen(dirp->res.d_name, sizeof(dirp->res.d_name)) < sizeof(dirp->res.d_name));
 103
 104         dirp->pos += len;
 105
 106         return &dirp->res;
 107 }
 108
 109 /** Rewind directory position to the beginning.
 110  *
 111  * @param dirp Open directory
 112  */
 113 void rewinddir(DIR *dirp)
 114 {
 115         dirp->pos = 0;
 116 }
 117
 118 /** Close directory.
 119  *
 120  * @param dirp Open directory
 121  * @return 0 on success. On error returns -1 and sets errno.
 122  */
 123 int closedir(DIR *dirp)
 124 {
 125         errno_t rc = vfs_put(dirp->fd);
 126         free(dirp);
 127
 128         if (rc == EOK) {
 129                 return 0;
 130         } else {
 131                 errno = rc;
 132                 return -1;
 133         }
 134 }
 135
 136 /** @}
 137  */