machdep.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

 * after restoring games from them.
 *
 * Again, this function is not strictly necessary, and can be stubbed
 * by simply returning 1.  In this case, saved-game files will not be
 * deleted and can be replayed.
 */

boolean
md_df(fname)
char *fname;
{
	if (unlink(fname)) {
		return(0);
	}
	return(1);
}

/* md_gln: (Get login name)
 *
 * This routine returns the login name of the user.  This string is
 * used mainly for identifying users in score files.
 *
 * A dummy string may be returned if you are unable to implement this
 * function, but then the score file would only have one name in it.
 */

char *
md_gln()
{
	struct passwd *p, *getpwuid();

	if (!(p = getpwuid(getuid())))
		return((char *)NULL);
	return(p->pw_name);
}

/* md_sleep:
 *
 * This routine causes the game to pause for the specified number of
 * seconds.
 *
 * This routine is not particularly necessary at all.  It is used for
 * delaying execution, which is useful to this program at some times.
 */

md_sleep(nsecs)
int nsecs;
{
	(void) sleep(nsecs);
}

/* md_getenv()
 *
 * This routine gets certain values from the user's environment.  These
 * values are strings, and each string is identified by a name.  The names
 * of the values needed, and their use, is as follows:
 *
 *   TERMCAP
 *     The name of the users's termcap file, NOT the termcap entries
 *     themselves.  This is used ONLY if the program is compiled with
 *     CURSES defined (-DCURSES).  Even in this case, the program need
 *     not find a string for TERMCAP.  If it does not, it will use the
 *     default termcap file as returned by md_gdtcf();
 *   TERM
 *     The name of the users's terminal.  This is used ONLY if the program
 *     is compiled with CURSES defined (-DCURSES).  In this case, the string
 *     value for TERM must be found, or the routines in curses.c cannot
 *     function, and the program will quit.
 *   ROGUEOPTS
 *     A string containing the various game options.  This need not be
 *     defined.
 *   HOME
 *     The user's home directory.  This is only used when the user specifies
 *     '~' as the first character of a saved-game file.  This string need
 *     not be defined.
 *   SHELL
 *     The user's favorite shell.  If not found, "/bin/sh" is assumed.
 *
 * If your system does not provide a means of searching for these values,
 * you will have to do it yourself.  None of the values above really need
 * to be defined except TERM when the program is compiled with CURSES
 * defined.  In this case, as a bare minimum, you can check the 'name'
 * parameter, and if it is "TERM" find the terminal name and return that,
 * else return zero.  If the program is not compiled with CURSES, you can
 * get by with simply always returning zero.  Returning zero indicates
 * that their is no defined value for the given string.
 */

char *
md_getenv(name)
char *name;
{
	char *value;
	char *getenv();

	value = getenv(name);

	return(value);
}

/* md_malloc()
 *
 * This routine allocates, and returns a pointer to, the specified number
 * of bytes.  This routines absolutely MUST be implemented for your
 * particular system or the program will not run at all.  Return zero
 * when no more memory can be allocated.
 */

char *
md_malloc(n)
int n;
{
	char *malloc();
	char *t;

	t = malloc(n);
	return(t);
}

/* md_gseed() (Get Seed)
 *
 * This function returns a seed for the random number generator (RNG).  This
 * seed causes the RNG to begin generating numbers at some point in it's
 * sequence.  Without a random seed, the RNG will generate the same set
 * of numbers, and every game will start out exactly the same way.  A good
 * number to use is the process id, given by getpid() on most UNIX systems.
 *
 * You need to find some single random integer, such as:
 *   process id.
 *   current time (minutes + seconds) returned from md_gct(), if implemented.
 *   
 * It will not help to return "get_rand()" or "rand()" or the return value of
 * any pseudo-RNG.  If you don't have a random number, you can just return 1,
 * but this means your games will ALWAYS start the same way, and will play
 * exactly the same way given the same input.
 */

md_gseed()
{
	return(getpid());
}

/* md_exit():
 *
 * This function causes the program to discontinue execution and exit.
 * This function must be implemented or the program will continue to
 * hang when it should quit.
 */

md_exit(status)
int status;
{
	exit(status);
}

/* md_lock():
 *
 * This function is intended to give the user exclusive access to the
 * score file.  It does so by "creat"ing a lock file, which can only
 * be created if it does not already exist.  The file is deleted when
 * score file processing is finished.  The lock file should be located
 * in the same directory as the score file.  These full path names should
 * be defined for any particular site in rogue.h.  The constants SCORE_FILE
 * and LOCK_FILE define these file names.
 *
 * When the parameter 'l' is non-zero (true), a lock is requested.  Otherwise
 * the lock is released by removing the lock file.
 */

md_lock(l)
boolean l;
{
	short tries;
	char *lock_file = LOCK_FILE;

	if (l) {
		for (tries = 0; tries < 5; tries++) {
			if (md_get_file_id(lock_file) == -1) {
				if (creat(lock_file, 0444) != -1) {
					break;
				} else {
					message("cannot lock score file", 0);
				}
			} else {
				message("waiting to lock score file", 0);
			}
			sleep(2);
		}
	} else {
		(void) unlink(lock_file);
	}
}

/* md_shell():
 *
 * This function spawns a shell for the user to use.  When this shell is
 * terminated, the game continues.  Since this program may often be run
 * setuid to gain access to privileged files, care is taken that the shell
 * is run with the user's REAL user id, and not the effective user id.
 * The effective user id is restored after the shell completes.
 */

md_shell(shell)
char *shell;
{
	long w[2];

	if (!fork()) {
		int uid;

		uid = getuid();
		setuid(uid);
		execl(shell, shell, 0);
	}
	wait(w);
}

/* If you have a viable curses/termlib library, then use it and don't bother
 * implementing the routines below.  And don't compile with -DCURSES.
 */

#ifdef CURSES

/* md_cbreak_no_echo_nonl:
 *
 * This routine sets up some terminal characteristics.  The tty-driver
 * must be told to:
 *   1.)  Not echo input.
 *   2.)  Transmit input characters immediately upon typing. (cbreak mode)
 *   3.)  Move the cursor down one line, without changing column, and
 *        without generating a carriage-return, when it
 *        sees a line-feed.  This is only necessary if line-feed is ever
 *        used in the termcap 'do' (cursor down) entry, in which case,
 *        your system should must have a way of accomplishing this.
 *
 * When the parameter 'on' is true, the terminal is set up as specified
 * above.  When this parameter is false, the terminal is restored to the
 * original state.
 *
 * Raw mode should not to be used.  Keyboard signals/events/interrupts should
 * be sent, although they are not strictly necessary.  See notes in
 * md_heed_signals().
 *
 * This function must be implemented for rogue to run properly if the
 * program is compiled with CURSES defined to use the enclosed curses
 * emulation package.  If you are not using this, then this routine is
 * totally unnecessary.
 * 
 * Notice that information is saved between calls.  This is used to
 * restore the terminal to an initial saved state.
 *
 */

md_cbreak_no_echo_nonl(on)
boolean on;
{
#ifdef UNIX_BSD4_2
	static struct sgttyb tty_buf;
	static int tsave_flags;

	if (on) {
		ioctl(0, TIOCGETP, &tty_buf);
		tsave_flags = tty_buf.sg_flags;
		tty_buf.sg_flags |= CBREAK;
		tty_buf.sg_flags &= ~(ECHO | CRMOD);	/* CRMOD: see note 3 above */
		ioctl(0, TIOCSETP, &tty_buf);
	} else {
		tty_buf.sg_flags = tsave_flags;
		ioctl(0, TIOCSETP, &tty_buf);
	}
#endif
#ifdef UNIX_SYSV
	struct termio tty_buf;
	static struct termio tty_save;

	if (on) {
		ioctl(0, TCGETA, &tty_buf);
		tty_save = tty_buf;
		tty_buf.c_lflag &= ~(ICANON | ECHO);
		tty_buf.c_oflag &= ~ONLCR;
		tty_buf.c_cc[4] = 1;  /* MIN */
		tty_buf.c_cc[5] = 2;  /* TIME */
		ioctl(0, TCSETAF, &tty_buf);
	} else {
		ioctl(0, TCSETAF, &tty_save);
	}
#endif
}

/* md_gdtcf(): (Get Default Termcap File)
 *
 * This function is called ONLY when the program is compiled with CURSES
 * defined.  If you use your system's curses/termlib library, this function
 * won't be called.  On most UNIX systems, "/etc/termcap" suffices.
 *
 * If their is no such termcap file, then return 0, but in that case, you
 * must have a TERMCAP file returned from md_getenv("TERMCAP").  The latter
 * will override the value returned from md_gdtcf().  If the program is
 * compiled with CURSES defined, and md_gdtcf() returns 0, and
 * md_getenv("TERMCAP") returns 0, the program will have no terminal
 * capability information and will quit.
 */

char *
md_gdtcf()
{
	return("/etc/termcap");
}

/* md_tstp():
 *
 * This function puts the game to sleep and returns to the shell.  This
 * only applies to UNIX 4.2 and 4.3.  For other systems, the routine should
 * be provided as a do-nothing routine.  md_tstp() will only be referenced
 * in the code when compiled with CURSES defined.
 *
 */

md_tstp()
{
#ifdef UNIX_BSD4_2
	kill(0, SIGTSTP);
#endif
}

#endif

#endif