libc/dirent/opendir.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2009  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19
  20 #include <vfs.h>
  21 #include <errno.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <dirent.h>
  26
  27 static vfs_dirent_t *getdir (const char *path)
  28 {
  29         vfs_dirent_t *d;
  30
  31         char *cwd = getcwd (0, 0);
  32
  33         if (!cwd)
  34                 return 0;
  35
  36         chdir (path);
  37
  38         asm volatile (
  39                 "movl $25, %%eax;"
  40                 "int $0x80;"
  41                 "movl %%eax, %0;"
  42                 : "=g" (d) :: "%eax");
  43
  44         chdir (cwd);
  45
  46         free (cwd);
  47
  48         return d;
  49 }
  50
  51 DIR *opendir (const char *name)
  52 {
  53         if (!name) {
  54                 errno = ENOENT;
  55                 return 0;
  56         }
  57
  58         vfs_dirent_t *ent = getdir (name);
  59
  60         if (!ent) {
  61                 errno = ENOENT;
  62                 return 0;
  63         }
  64
  65         DIR *dir = (DIR *) malloc (sizeof (DIR));
  66
  67         if (!dir) {
  68                 errno = ENOMEM;
  69                 return 0;
  70         }
  71
  72         unsigned l = strlen (name);
  73
  74         if (l > NAME_MAX)
  75                 l = NAME_MAX;
  76
  77         memcpy (dir->name, name, l);
  78         dir->name[l] = '\0';
  79
  80         unsigned id, m;
  81
  82         /* count entries in dir structure */
  83         for (id = 0; ent[id].next; id ++);
  84
  85         m = id + 1;
  86
  87         dir->entry = (struct dirent *) malloc (sizeof (struct dirent) * (m + 1));
  88
  89         if (!dir->entry) {
  90                 free (dir);
  91                 errno = ENOMEM;
  92                 return 0;
  93         }
  94
  95         /* create entires as dirents */
  96         for (id = 0; id < m; id ++) {
  97                 dir->entry[id].d_ino = 0;       /* TODO */
  98                 dir->entry[id].d_off = id * sizeof (struct dirent);
  99                 dir->entry[id].d_reclen = sizeof (struct dirent);
 100
 101                 if (!ent[id].name)
 102                         continue;
 103
 104                 l = strlen (ent[id].name);
 105
 106                 if (l > NAME_MAX)
 107                         l = NAME_MAX;
 108
 109                 memcpy (dir->entry[id].d_name, ent[id].name, l);
 110                 dir->entry[id].d_name[l] = '\0';
 111         }
 112
 113         /* create last entry as eof */
 114         dir->entry[m].d_ino = -1;
 115         dir->entry[m].d_off = m * sizeof (struct dirent);
 116         dir->entry[m].d_reclen = 0;
 117         dir->entry[m].d_name[0] = '\0';
 118
 119         return dir;
 120 }