/*
 * $Id: unistd_chdir.c,v 1.7 2005-04-24 08:46:37 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2005 by Olaf Barthel <olsen@sourcery.han.de>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Neither the name of Olaf Barthel nor the names of contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _STDLIB_NULL_POINTER_CHECK_H
#include "stdlib_null_pointer_check.h"
#endif /* _STDLIB_NULL_POINTER_CHECK_H */

/****************************************************************************/

#ifndef _UNISTD_HEADERS_H
#include "unistd_headers.h"
#endif /* _UNISTD_HEADERS_H */

/****************************************************************************/

/* The following is not part of the ISO 'C' (1994) standard. */

/****************************************************************************/

/* ZZZ chdir() must be reentrant according to POSIX.1 */
int
chdir(const char * path_name)
{
	#if defined(UNIX_PATH_SEMANTICS)
	struct name_translation_info path_name_nti;
	#endif /* UNIX_PATH_SEMANTICS */
	D_S(struct FileInfoBlock,fib);
	BPTR dir_lock = ZERO;
	LONG status;
	int result = ERROR;

	ENTER();

	SHOWSTRING(path_name);

	assert( path_name != NULL );

	if(__check_abort_enabled)
		__check_abort();

	#if defined(CHECK_FOR_NULL_POINTERS)
	{
		if(path_name == NULL)
		{
			SHOWMSG("invalid path name");

			__set_errno(EFAULT);
			goto out;
		}
	}
	#endif /* CHECK_FOR_NULL_POINTERS */

	#if defined(UNIX_PATH_SEMANTICS)
	{
		if(__unix_path_semantics)
		{
			if(__translate_unix_to_amiga_path_name(&path_name,&path_name_nti) != 0)
				goto out;

			/* The pseudo root directory is a very special case indeed. We
			 * just accept it and don't pretend to have obtained a lock
			 * on anything.
			 */
			if(path_name_nti.is_root)
			{
				SHOWMSG("this is the / directory");

				__restore_path_name(&path_name,&path_name_nti);

				/* ZZZ this must not fail */
				__set_current_path(path_name);

				result = OK;

				goto out;
			}
		}
	}
	#endif /* UNIX_PATH_SEMANTICS */

	D(("trying to get a lock on '%s'",path_name));

	PROFILE_OFF();
	dir_lock = Lock((STRPTR)path_name,SHARED_LOCK);
	PROFILE_ON();

	if(dir_lock == ZERO)
	{
		__set_errno(__translate_access_io_error_to_errno(IoErr()));
		goto out;
	}

	PROFILE_OFF();
	status = Examine(dir_lock,fib);
	PROFILE_ON();

	if(status == DOSFALSE)
	{
		__set_errno(__translate_io_error_to_errno(IoErr()));
		goto out;
	}

	if(fib->fib_DirEntryType < 0)
	{
		SHOWMSG("this is not a directory");

		__set_errno(ENOTDIR);
		goto out;
	}

	PROFILE_OFF();

	if(__current_directory_changed)
	{
		BPTR old_dir;

		old_dir = CurrentDir(dir_lock);

		if(__unlock_current_directory)
			UnLock(old_dir);
	}
	else
	{
		__original_current_directory = CurrentDir(dir_lock);

		__current_directory_changed = TRUE;
	}

	__unlock_current_directory = TRUE;

	PROFILE_ON();

	dir_lock = ZERO;

	#if defined(UNIX_PATH_SEMANTICS)
	{
		if(__unix_path_semantics)
			__restore_path_name(&path_name,&path_name_nti);

		/* ZZZ this must not fail */
		__set_current_path(path_name);
	}
	#endif /* UNIX_PATH_SEMANTICS */

	result = OK;

 out:

	PROFILE_OFF();
	UnLock(dir_lock);
	PROFILE_ON();

	RETURN(result);
	return(result);
}
