libsysio/src/readdir.c

   1 /*
   2  * This library is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU Lesser General Public
   4  * License as published by the Free Software Foundation; either
   5  * version 2.1 of the License, or (at your option) any later version.
   6  *
   7  * This library is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10  * Lesser General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU Lesser General Public
  13  * License along with this library; if not, write to the Free Software
  14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  15  *
  16  */
  17
  18 #ifdef __linux__
  19 #include <features.h>
  20 #if defined(__GLIBC__) && !defined(REDSTORM)
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #include <dirent.h>
  27 #include <sysio.h>
  28
  29 #include "sysio-symbols.h"
  30
  31 #ifndef _READDIR
  32 #define _READDIR SYSIO_INTERFACE_NAME(readdir)
  33 #define _SCANDIR SYSIO_INTERFACE_NAME(scandir)
  34 #define _GETDIRENTRIES SYSIO_INTERFACE_NAME(getdirentries)
  35 #define _DIRENT_T struct dirent
  36 #define _OFF_T off_t
  37 #endif
  38
  39 #include "stddir.h"
  40
  41 _DIRENT_T *
  42 _READDIR(DIR *dir)
  43 {
  44         _DIRENT_T *dp = NULL;
  45         _OFF_T dbase;
  46
  47 #ifndef BSD
  48         ssize_t rc;
  49 #else
  50         int rc;
  51 #endif
  52         SYSIO_INTERFACE_DISPLAY_BLOCK;
  53
  54         SYSIO_INTERFACE_ENTER;
  55
  56         /* need to read new data? */
  57         rc = 0;
  58         if (dir->cur >= dir->effective) {
  59                 dir->cur = 0;
  60                 dbase = (_OFF_T )dir->base;
  61                 if (sizeof(dbase) != sizeof(dir->base) &&
  62                     dbase != dir->base) {
  63                         dir->effective = 0;
  64                         SYSIO_INTERFACE_RETURN(NULL, -EOVERFLOW);
  65                 }
  66                 rc = _GETDIRENTRIES(dir->fd,
  67                                     dir->buf,
  68 #ifndef BSD
  69                                     (size_t )BUFSIZE,
  70                                     (_OFF_T *) &dbase);
  71 #else
  72                                     (int )BUFSIZE,
  73                                     (long *) __restrict dbase);
  74 #endif
  75                 dir->base = (_SYSIO_OFF_T )dbase;
  76
  77                 /* error or end-of-file */
  78                 if (rc == -ENOENT)
  79                         rc = 0;
  80                 if (rc <= 0) {
  81                         dir->effective = 0;
  82                         SYSIO_INTERFACE_RETURN(NULL, rc);
  83                 }
  84                 dir->effective = rc;
  85         }
  86         dp = (_DIRENT_T *)(dir->buf + dir->cur);
  87
  88 #ifdef _DIRENT_HAVE_D_RECLEN
  89         dir->cur += dp->d_reclen;
  90 #else
  91         dir->cur += sizeof(_DIRENT_T);
  92 #endif
  93 #ifdef _DIRENT_HAVE_D_OFF
  94         dir->filepos = dp->d_off;
  95 #else
  96         dir->filepos = dir->cur;
  97 #endif
  98
  99         SYSIO_INTERFACE_RETURN(dp, 0);
 100 }
 101
 102 sysio_sym_weak_alias(_READDIR, PREPEND(__,_READDIR))
 103
 104 int
 105 _SCANDIR(const char *dirname,
 106          _DIRENT_T ***namelist,
 107          int (*filter) (const _DIRENT_T *),
 108          int (*compar) (const void *, const void *))
 109 {
 110         DIR *dir = NULL;
 111         _DIRENT_T *de     = NULL,
 112                   *nextde = NULL,
 113                   **s     = NULL;
 114         int n = 32, i = 0;
 115         size_t desize;
 116         SYSIO_INTERFACE_DISPLAY_BLOCK;
 117
 118         SYSIO_INTERFACE_ENTER;
 119
 120         if ((dir = SYSIO_INTERFACE_NAME(opendir)(dirname)) == NULL)
 121                 SYSIO_INTERFACE_RETURN(-1, -errno);
 122
 123         while ((de = _READDIR(dir)) != NULL) {
 124                 if ((filter == NULL) || filter(de)) {
 125                         if (i == 0 || i >= n) {
 126                             n = MAX(n, 2*i);
 127                             s = (_DIRENT_T **)realloc(s,
 128                                 (size_t )(n * sizeof(_DIRENT_T *)));
 129                             if (!s)
 130                                 SYSIO_INTERFACE_RETURN(-1, -ENOMEM);
 131                         }
 132                         desize = &de->d_name[_D_ALLOC_NAMLEN(de)] - (char * )de;
 133                         nextde = (_DIRENT_T *)malloc(desize);
 134                         if (!nextde)
 135                                 SYSIO_INTERFACE_RETURN(-1, -ENOMEM);
 136
 137                         s[i++] = (_DIRENT_T *)memcpy(nextde, de, desize);
 138                 }
 139         }
 140         if (compar)
 141                 qsort (s,
 142                        i,
 143                        sizeof (*s),
 144                        (int (*)(const void *, const void *))compar);
 145
 146         *namelist = s;
 147
 148         SYSIO_INTERFACE_NAME(closedir)(dir);
 149
 150         SYSIO_INTERFACE_RETURN(i, 0);
 151 }
 152
 153 sysio_sym_weak_alias(_SCANDIR, PREPEND(__,_SCANDIR))
 154
 155 #endif
 156 #endif