uclibc-ng/libc/sysdeps/linux/common/getdirname.c

/* vi: set sw=4 ts=4: */
/* Copyright (C) 1992, 1997, 1998, 2000 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 Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <features.h>
#include <unistd.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>

libc_hidden_proto(strdup)
libc_hidden_proto(getcwd)
libc_hidden_proto(getenv)
#ifdef __UCLIBC_HAS_LFS__
libc_hidden_proto(stat64)
#else
libc_hidden_proto(stat)
#endif

/* Return a malloc'd string containing the current directory name.
   If the environment variable `PWD' is set, and its value is correct,
   that value is used.  */

char *
get_current_dir_name (void)
{
	char *pwd;
#ifdef __UCLIBC_HAS_LFS__
	struct stat64 dotstat, pwdstat;
#else
	struct stat dotstat, pwdstat;
#endif

	pwd = getenv ("PWD");
	if (pwd != NULL
#ifdef __UCLIBC_HAS_LFS__
		&& stat64 (".", &dotstat) == 0
		&& stat64 (pwd, &pwdstat) == 0
#else
		&& stat (".", &dotstat) == 0
		&& stat (pwd, &pwdstat) == 0
#endif
		&& pwdstat.st_dev == dotstat.st_dev
		&& pwdstat.st_ino == dotstat.st_ino)
		/* The PWD value is correct.  Use it.  */
		return strdup (pwd);

	return getcwd ((char *) NULL, 0);
}