dirent/scandir.c

   1 /* Copyright (C) 1992-1998, 2000, 2002, 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <dirent.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <errno.h>
  23
  24 #ifndef SCANDIR
  25 #define SCANDIR scandir
  26 #define READDIR __readdir
  27 #define DIRENT_TYPE struct dirent
  28 #endif
  29
  30
  31 int
  32 SCANDIR (dir, namelist, select, cmp)
  33      const char *dir;
  34      DIRENT_TYPE ***namelist;
  35      int (*select) (const DIRENT_TYPE *);
  36      int (*cmp) (const void *, const void *);
  37 {
  38   DIR *dp = __opendir (dir);
  39   DIRENT_TYPE **v = NULL;
  40   size_t vsize = 0, i;
  41   DIRENT_TYPE *d;
  42   int save;
  43
  44   if (dp == NULL)
  45     return -1;
  46
  47   save = errno;
  48   __set_errno (0);
  49
  50   i = 0;
  51   while ((d = READDIR (dp)) != NULL)
  52     {
  53       int use_it = select == NULL;
  54
  55       if (! use_it)
  56         {
  57           use_it = select (d);
  58           /* The select function might have changed errno.  It was
  59              zero before and it need to be again to make the latter
  60              tests work.  */
  61           __set_errno (0);
  62         }
  63
  64       if (use_it)
  65         {
  66           DIRENT_TYPE *vnew;
  67           size_t dsize;
  68
  69           /* Ignore errors from select or readdir */
  70           __set_errno (0);
  71
  72           if (__builtin_expect (i == vsize, 0))
  73             {
  74               DIRENT_TYPE **new;
  75               if (vsize == 0)
  76                 vsize = 10;
  77               else
  78                 vsize *= 2;
  79               new = (DIRENT_TYPE **) realloc (v, vsize * sizeof (*v));
  80               if (new == NULL)
  81                 break;
  82               v = new;
  83             }
  84
  85           dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
  86           vnew = (DIRENT_TYPE *) malloc (dsize);
  87           if (vnew == NULL)
  88             break;
  89
  90           v[i++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize);
  91         }
  92     }
  93
  94   if (__builtin_expect (errno, 0) != 0)
  95     {
  96       save = errno;
  97
  98       while (i > 0)
  99         free (v[--i]);
 100       free (v);
 101
 102       i = -1;
 103     }
 104   else
 105     {
 106       /* Sort the list if we have a comparison function to sort with.  */
 107       if (cmp != NULL)
 108         qsort (v, i, sizeof (*v), cmp);
 109
 110       *namelist = v;
 111     }
 112
 113   (void) __closedir (dp);
 114   __set_errno (save);
 115
 116   return i;
 117 }