dirent/scandirat.c

   1 /* Copyright (C) 1992-1998,2000,2002,2003,2009,2011
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <dirent.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <bits/libc-lock.h>
  25
  26 #ifndef SCANDIRAT
  27 # define SCANDIRAT scandirat
  28 # define READDIR __readdir
  29 # define DIRENT_TYPE struct dirent
  30 #endif
  31
  32 #ifndef SKIP_SCANDIR_CANCEL
  33 void
  34 __scandir_cancel_handler (void *arg)
  35 {
  36   struct scandir_cancel_struct *cp = arg;
  37   size_t i;
  38   void **v = cp->v;
  39
  40   for (i = 0; i < cp->cnt; ++i)
  41     free (v[i]);
  42   free (v);
  43   (void) __closedir (cp->dp);
  44 }
  45 #endif
  46
  47
  48 int
  49 SCANDIRAT (dfd, dir, namelist, select, cmp)
  50      int dfd;
  51      const char *dir;
  52      DIRENT_TYPE ***namelist;
  53      int (*select) (const DIRENT_TYPE *);
  54      int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **);
  55 {
  56   DIR *dp = __opendirat (dfd, dir);
  57   DIRENT_TYPE **v = NULL;
  58   size_t vsize = 0;
  59   struct scandir_cancel_struct c;
  60   DIRENT_TYPE *d;
  61   int save;
  62
  63   if (dp == NULL)
  64     return -1;
  65
  66   save = errno;
  67   __set_errno (0);
  68
  69   c.dp = dp;
  70   c.v = NULL;
  71   c.cnt = 0;
  72   __libc_cleanup_push (__scandir_cancel_handler, &c);
  73
  74   while ((d = READDIR (dp)) != NULL)
  75     {
  76       int use_it = select == NULL;
  77
  78       if (! use_it)
  79         {
  80           use_it = select (d);
  81           /* The select function might have changed errno.  It was
  82              zero before and it need to be again to make the latter
  83              tests work.  */
  84           __set_errno (0);
  85         }
  86
  87       if (use_it)
  88         {
  89           DIRENT_TYPE *vnew;
  90           size_t dsize;
  91
  92           /* Ignore errors from select or readdir */
  93           __set_errno (0);
  94
  95           if (__builtin_expect (c.cnt == vsize, 0))
  96             {
  97               DIRENT_TYPE **new;
  98               if (vsize == 0)
  99                 vsize = 10;
 100               else
 101                 vsize *= 2;
 102               new = (DIRENT_TYPE **) realloc (v, vsize * sizeof (*v));
 103               if (new == NULL)
 104                 break;
 105               v = new;
 106               c.v = (void *) v;
 107             }
 108
 109           dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
 110           vnew = (DIRENT_TYPE *) malloc (dsize);
 111           if (vnew == NULL)
 112             break;
 113
 114           v[c.cnt++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize);
 115         }
 116     }
 117
 118   if (__builtin_expect (errno, 0) != 0)
 119     {
 120       save = errno;
 121
 122       while (c.cnt > 0)
 123         free (v[--c.cnt]);
 124       free (v);
 125       c.cnt = -1;
 126     }
 127   else
 128     {
 129       /* Sort the list if we have a comparison function to sort with.  */
 130       if (cmp != NULL)
 131         qsort (v, c.cnt, sizeof (*v),
 132                (int (*) (const void *, const void *)) cmp);
 133
 134       *namelist = v;
 135     }
 136
 137   __libc_cleanup_pop (0);
 138
 139   (void) __closedir (dp);
 140   __set_errno (save);
 141
 142   return c.cnt;
 143 }
 144 libc_hidden_def (SCANDIRAT)