mdw@git.distorted.org.uk Git - dpkg/blob - lib/compat/scandir.c

   1 /*
   2  * libcompat - system compatibility library
   3  *
   4  * Copyright © 1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
   5  * Copyright © 2008, 2009 Guillem Jover <guillem@debian.org>
   6  *
   7  * This is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22
  23 #include <sys/types.h>
  24
  25 #include <string.h>
  26 #include <dirent.h>
  27 #include <stdlib.h>
  28
  29 #include "compat.h"
  30
  31 static int
  32 cleanup(DIR *dir, struct dirent **dirlist, int used)
  33 {
  34         if (dir)
  35                 closedir(dir);
  36
  37         if (dirlist) {
  38                 int i;
  39
  40                 for (i = 0; i < used; i++)
  41                         free(dirlist[i]);
  42                 free(dirlist);
  43         }
  44
  45         return -1;
  46 }
  47
  48 int
  49 scandir(const char *dir, struct dirent ***namelist,
  50         int (*filter)(const struct dirent *),
  51         int (*cmp)(const void *, const void *))
  52 {
  53         DIR *d;
  54         struct dirent *e, *m, **list;
  55         int used, avail;
  56
  57         d = opendir(dir);
  58         if (!d)
  59                 return -1;
  60
  61         list = NULL;
  62         used = avail = 0;
  63
  64         while ((e = readdir(d)) != NULL) {
  65                 if (filter != NULL && !filter(e))
  66                         continue;
  67
  68                 if (used >= avail - 1) {
  69                         struct dirent **newlist;
  70
  71                         if (avail)
  72                                 avail *= 2;
  73                         else
  74                                 avail = 20;
  75                         newlist = realloc(list, avail * sizeof(struct dirent *));
  76                         if (!newlist)
  77                                 return cleanup(d, list, used);
  78                         list = newlist;
  79                 }
  80
  81                 m = malloc(sizeof(struct dirent) + strlen(e->d_name));
  82                 if (!m)
  83                         return cleanup(d, list, used);
  84                 *m = *e;
  85                 strcpy(m->d_name, e->d_name);
  86
  87                 list[used] = m;
  88                 used++;
  89         }
  90
  91         closedir(d);
  92
  93         if (list != NULL && cmp != NULL)
  94                 qsort(list, used, sizeof(struct dirent *), cmp);
  95
  96         *namelist = list;
  97
  98         return used;
  99 }