int cmd_cd(char dir[])
{
	char temp[256];
	unsigned result;

	if (NULL == dir) {
		printf(CMD_CD_USAGE);
		return TRUE;
	}

	if ( 0 == strcmp(dir, ".") || 0 == strcmp(dir, "./") )
		return TRUE;

	if (  ( 0 == strcmp(dir, "..") ||  0 == strcmp(dir, "../") ) && ( 0 != strcmp(cur_dir, "/")) ) {
		cur_dir[strlen(cur_dir)-1]='\0';
		dir_truncate(cur_dir);
		set_cwd(cur_dir);
		return TRUE;
	}

	if ( '/' == dir[0]) {
		if ( dir_check(dir) )
			{
			strcpy(cur_dir, dir);
			set_cwd(cur_dir);
			return TRUE;
			}
		return FALSE;
	}
	else {
		strcpy(temp, cur_dir);
		if (cur_dir[strlen(cur_dir)-1] != '/')
			strcat(temp, "/");
		strcat(temp, dir);

		if ( dir_check(temp) ) {

			strcpy(cur_dir, temp);
			set_cwd(cur_dir);
			return TRUE;
		}

		return FALSE;
	}

}