mes/lib/dirent/opendir.c

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/* -*-comment-start: "//";comment-end:""-*-
* GNU Mes --- Maxwell Equations of Software
* Copyright (C) 1991-1996,98,2000,2001 Free Software Foundation, Inc.
* Copyright © 2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
*
* This file is part of GNU Mes.
*
* GNU Mes is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* GNU Mes 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
*/
// Taken from GNU C Library 2.2.5
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <dirstream.h>
/* Open a directory stream on NAME. */
DIR *
opendir (char const *name)
{
DIR *dirp;
struct stat statbuf;
int fd;
size_t allocation;
int save_errno;
if (name[0] == '\0')
{
/* POSIX.1-1990 says an empty name gets ENOENT;
but `open' might like it fine. */
errno = ENOENT;
return 0;
}
fd = open (name, O_RDONLY | O_DIRECTORY);
if (fd < 0)
return 0;
if (fstat (fd, &statbuf) < 0)
goto lose;
if (fcntl (fd, F_SETFD, FD_CLOEXEC) < 0)
goto lose;
allocation = statbuf.st_blksize;
dirp = (DIR *) calloc (1, sizeof (DIR) + allocation);
if (!dirp)
lose:
{
save_errno = errno;
close (fd);
errno = save_errno;
return 0;
}
dirp->data = (char *) (dirp + 1);
dirp->allocation = allocation;
dirp->fd = fd;
return dirp;
}