glibc/sysdeps/unix/opendir.c

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1995-02-18 09:27:10 +08:00
/* Copyright (C) 1991, 1992, 1993, 1994 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 <ansidecl.h>
#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 "direct.h" /* This file defines `struct direct'. */
/* Open a directory stream on NAME. */
DIR *
DEFUN(opendir, (name), CONST char *name)
{
DIR *dirp;
struct stat statbuf;
int fd;
if (name[0] == '\0')
{
/* POSIX.1-1990 says an empty name gets ENOENT;
but `open' might like it fine. */
errno = ENOENT;
return NULL;
}
fd = __open (name, O_RDONLY);
if (fd < 0)
return NULL;
if (fcntl (fd, F_SETFD, FD_CLOEXEC) < 0)
goto lose;
if (fstat (fd, &statbuf) < 0)
goto lose;
if (! S_ISDIR (statbuf.st_mode))
{
errno = ENOTDIR;
goto lose;
}
dirp = (DIR *) calloc (1, sizeof (DIR) + NAME_MAX); /* Zero-fill. */
if (dirp == NULL)
lose:
{
int save = errno;
(void) __close (fd);
errno = save;
return NULL;
}
#ifdef _STATBUF_ST_BLKSIZE
if (statbuf.st_blksize < sizeof (struct direct))
dirp->__allocation = sizeof (struct direct);
else
dirp->__allocation = statbuf.st_blksize;
#else
dirp->__allocation = (BUFSIZ < sizeof (struct direct) ?
sizeof (struct direct) : BUFSIZ);
#endif
dirp->__data = (char *) malloc (dirp->__allocation);
if (dirp->__data == NULL)
{
int save = errno;
free ((PTR) dirp);
(void) __close (fd);
errno = save;
return NULL;
}
dirp->__fd = fd;
return dirp;
}