glibc/dirent/scandir.c

/* Copyright (C) 1992, 1993, 1994, 1995, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <dirent.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

int
scandir (dir, namelist, select, cmp)
     const char *dir;
     struct dirent ***namelist;
     int (*select) __P ((struct dirent *));
     int (*cmp) __P ((const void *, const void *));
{
  DIR *dp = opendir (dir);
  struct dirent **v = NULL;
  size_t vsize = 0, i;
  struct dirent *d;
  int save;

  if (dp == NULL)
    return -1;

  save = errno;
  __set_errno (0);

  i = 0;
  while ((d = readdir (dp)) != NULL)
    if (select == NULL || (*select) (d))
      {
	size_t dsize;

	if (i == vsize)
	  {
	    struct dirent **new;
	    if (vsize == 0)
	      vsize = 10;
	    else
	      vsize *= 2;
	    new = (struct dirent **) realloc (v, vsize * sizeof (*v));
	    if (new == NULL)
	      {
	      lose:
		__set_errno (ENOMEM);
		break;
	      }
	    v = new;
	  }

	dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
	v[i] = (struct dirent *) malloc (dsize);
	if (v[i] == NULL)
	  goto lose;

	memcpy (v[i++], d, dsize);
      }

  if (errno != 0)
    {
      save = errno;
      (void) closedir (dp);
      while (i > 0)
	free (v[--i]);
      free (v);
      __set_errno (save);
      return -1;
    }

  (void) closedir (dp);
  __set_errno (save);

  /* Sort the list if we have a comparison function to sort with.  */
  if (cmp != NULL)
    qsort (v, i, sizeof (*v), cmp);
  *namelist = v;
  return i;
}