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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <dirent.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <errno.h>
  23 #include <bits/libc-lock.h>
  24
  25 #ifndef SCANDIRAT
  26 # define SCANDIRAT scandirat
  27 # define READDIR __readdir
  28 # define DIRENT_TYPE struct dirent
  29 #endif
  30
  31 #ifndef SKIP_SCANDIR_CANCEL
  32 void
  33 __scandir_cancel_handler (void *arg)
  34 {
  35   struct scandir_cancel_struct *cp = arg;
  36   size_t i;
  37   void **v = cp->v;
  38
  39   for (i = 0; i < cp->cnt; ++i)
  40     free (v[i]);
  41   free (v);
  42   (void) __closedir (cp->dp);
  43 }
  44 #endif
  45
  46
  47 int
  48 SCANDIRAT (dfd, dir, namelist, select, cmp)
  49      int dfd;
  50      const char *dir;
  51      DIRENT_TYPE ***namelist;
  52      int (*select) (const DIRENT_TYPE *);
  53      int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **);
  54 {
  55   DIR *dp = __opendirat (dfd, dir);
  56   DIRENT_TYPE **v = NULL;
  57   size_t vsize = 0;
  58   struct scandir_cancel_struct c;
  59   DIRENT_TYPE *d;
  60   int save;
  61
  62   if (dp == NULL)
  63     return -1;
  64
  65   save = errno;
  66   __set_errno (0);
  67
  68   c.dp = dp;
  69   c.v = NULL;
  70   c.cnt = 0;
  71   __libc_cleanup_push (__scandir_cancel_handler, &c);
  72
  73   while ((d = READDIR (dp)) != NULL)
  74     {
  75       int use_it = select == NULL;
  76
  77       if (! use_it)
  78         {
  79           use_it = select (d);
  80           /* The select function might have changed errno.  It was
  81              zero before and it need to be again to make the latter
  82              tests work.  */
  83           __set_errno (0);
  84         }
  85
  86       if (use_it)
  87         {
  88           DIRENT_TYPE *vnew;
  89           size_t dsize;
  90
  91           /* Ignore errors from select or readdir */
  92           __set_errno (0);
  93
  94           if (__builtin_expect (c.cnt == vsize, 0))
  95             {
  96               DIRENT_TYPE **new;
  97               if (vsize == 0)
  98                 vsize = 10;
  99               else
 100                 vsize *= 2;
 101               new = (DIRENT_TYPE **) realloc (v, vsize * sizeof (*v));
 102               if (new == NULL)
 103                 break;
 104               v = new;
 105               c.v = (void *) v;
 106             }
 107
 108           dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
 109           vnew = (DIRENT_TYPE *) malloc (dsize);
 110           if (vnew == NULL)
 111             break;
 112
 113           v[c.cnt++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize);
 114         }
 115     }
 116
 117   if (__builtin_expect (errno, 0) != 0)
 118     {
 119       save = errno;
 120
 121       while (c.cnt > 0)
 122         free (v[--c.cnt]);
 123       free (v);
 124       c.cnt = -1;
 125     }
 126   else
 127     {
 128       /* Sort the list if we have a comparison function to sort with.  */
 129       if (cmp != NULL)
 130         qsort (v, c.cnt, sizeof (*v),
 131                (int (*) (const void *, const void *)) cmp);
 132
 133       *namelist = v;
 134     }
 135
 136   __libc_cleanup_pop (0);
 137
 138   (void) __closedir (dp);
 139   __set_errno (save);
 140
 141   return c.cnt;
 142 }
 143 libc_hidden_def (SCANDIRAT)