main.c

早期freebsd实现

			goto err;
	}

	/* Set up the argument pointer. */
	sp->a_frp = sp->frp;

	/*
	 * If there's an initial command, push it on the command stack.
	 * Historically, it was always an ex command, not vi in vi mode
	 * or ex in ex mode.  So, make it look like an ex command to vi.
	 */
	if (excmdarg != NULL)
		if (IN_EX_MODE(sp)) {
			if (term_push(sp, excmdarg, strlen(excmdarg), 0, 0))
				goto err;
		} else if (IN_VI_MODE(sp)) {
			if (term_push(sp, "\n", 1, 0, 0))
				goto err;
			if (term_push(sp, excmdarg, strlen(excmdarg), 0, 0))
				goto err;
			if (term_push(sp, ":", 1, 0, 0))
				goto err;
		}

	/*
	 * Initialize the signals.  Use sigaction(2), not signal(3), because
	 * we don't want to always restart system calls on 4BSD systems.  It
	 * would be nice in some cases to restart system calls, but SA_RESTART
	 * is a 4BSD extension so we can't use it.
	 *
	 * SIGALRM:
	 *	Walk structures and call handling routines.
	 * SIGHUP, SIGTERM, SIGWINCH:
	 *	Catch and set a global bit.
	 * SIGQUIT:
	 *	Always ignore.
	 */
	act.sa_handler = h_alrm;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	if (sigaction(SIGALRM, &act, NULL)) {
		msgq(sp, M_SYSERR, "timer: sigaction");
		goto err;
	}
	act.sa_handler = h_hup;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	(void)sigaction(SIGHUP, &act, NULL);
	act.sa_handler = h_term;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	(void)sigaction(SIGTERM, &act, NULL);
	act.sa_handler = h_winch;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	(void)sigaction(SIGWINCH, &act, NULL);
	act.sa_handler = SIG_IGN;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	(void)sigaction(SIGQUIT, &act, NULL);

	for (;;) {
		if (sp->s_edit(sp, sp->ep))
			goto err;

		/*
		 * Edit the next screen on the display queue, or, move
		 * a screen from the hidden queue to the display queue.
		 */
		if ((sp = __global_list->dq.cqh_first) ==
		    (void *)&__global_list->dq)
			if ((sp = __global_list->hq.cqh_first) !=
			    (void *)&__global_list->hq) {
				CIRCLEQ_REMOVE(&sp->gp->hq, sp, q);
				CIRCLEQ_INSERT_TAIL(&sp->gp->dq, sp, q);
			} else
				break;

		/*
		 * The screen type may have changed -- reinitialize the
		 * functions in case it has.
		 */
		switch (F_ISSET(sp, S_SCREENS)) {
		case S_EX:
			if (sex_screen_init(sp))
				goto err;
			break;
		case S_VI_CURSES:
			if (svi_screen_init(sp))
				goto err;
			break;
		case S_VI_XAW:
			if (xaw_screen_init(sp))
				goto err;
			break;
		default:
			abort();
		}
	}

	eval = 0;
	if (0)
err:		eval = 1;

	/*
	 * NOTE: sp may be GONE when the screen returns, so only
	 * the gp can be trusted.
	 */
	gs_end(gp);

	exit(eval);
}

/*
 * gs_init --
 *	Build and initialize the GS structure.
 */
static GS *
gs_init()
{
	GS *gp;
	int fd;

	CALLOC_NOMSG(NULL, gp, GS *, 1, sizeof(GS));
	if (gp == NULL)
		err(1, NULL);

	CIRCLEQ_INIT(&gp->dq);
	CIRCLEQ_INIT(&gp->hq);
	LIST_INIT(&gp->msgq);

	/* Structures shared by screens so stored in the GS structure. */
	CALLOC_NOMSG(NULL, gp->tty, IBUF *, 1, sizeof(IBUF));
	if (gp->tty == NULL)
		err(1, NULL);

	LIST_INIT(&gp->cutq);
	LIST_INIT(&gp->seqq);

	/* Set a flag if we're reading from the tty. */
	if (isatty(STDIN_FILENO))
		F_SET(gp, G_STDIN_TTY);

	/*
	 * Set the G_STDIN_TTY flag.  It's purpose is to avoid setting and
	 * resetting the tty if the input isn't from there.
	 *
	 * Set the G_TERMIOS_SET flag.  It's purpose is to avoid using the
	 * original_termios information (mostly special character values)
	 * if it's not valid.  We expect that if we've lost our controlling
	 * terminal that the open() (but not the tcgetattr()) will fail.
	 */
	if (F_ISSET(gp, G_STDIN_TTY)) {
		if (tcgetattr(STDIN_FILENO, &gp->original_termios) == -1)
			err(1, "tcgetattr");
		F_SET(gp, G_TERMIOS_SET);
	} else if ((fd = open(_PATH_TTY, O_RDONLY, 0)) != -1) {
		if (tcgetattr(fd, &gp->original_termios) == -1)
			err(1, "tcgetattr");
		F_SET(gp, G_TERMIOS_SET);
		(void)close(fd);
	}
	return (gp);
}


/*
 * gs_end --
 *	End the GS structure.
 */
static void
gs_end(gp)
	GS *gp;
{
	MSG *mp;
	SCR *sp;
	char *tty;

	/* Reset anything that needs resetting. */
	if (gp->flags & G_SETMODE)			/* O_MESG */
		if ((tty = ttyname(STDERR_FILENO)) == NULL)
			warn("ttyname");
		else if (chmod(tty, gp->origmode) < 0)
			warn("%s", tty);

	/* Ring the bell if scheduled. */
	if (F_ISSET(gp, G_BELLSCHED))
		(void)fprintf(stderr, "\07");		/* \a */

	/* If there are any remaining screens, flush their messages. */
	for (sp = __global_list->dq.cqh_first;
	    sp != (void *)&__global_list->dq; sp = sp->q.cqe_next)
		for (mp = sp->msgq.lh_first;
		    mp != NULL && !(F_ISSET(mp, M_EMPTY)); mp = mp->q.le_next)
			(void)fprintf(stderr, "%.*s\n", (int)mp->len, mp->mbuf);
	for (sp = __global_list->hq.cqh_first;
	    sp != (void *)&__global_list->hq; sp = sp->q.cqe_next)
		for (mp = sp->msgq.lh_first;
		    mp != NULL && !(F_ISSET(mp, M_EMPTY)); mp = mp->q.le_next)
			(void)fprintf(stderr, "%.*s\n", (int)mp->len, mp->mbuf);
	/* Flush messages on the global queue. */
	for (mp = gp->msgq.lh_first;
	    mp != NULL && !(F_ISSET(mp, M_EMPTY)); mp = mp->q.le_next)
		(void)fprintf(stderr, "%.*s\n", (int)mp->len, mp->mbuf);

	if (gp->special_key != NULL)
		FREE(gp->special_key, MAX_FAST_KEY);

	/*
	 * DON'T FREE THE GLOBAL STRUCTURE -- WE DIDN'T TURN
	 * OFF SIGNALS/TIMERS, SO IT MAY STILL BE REFERENCED.
	 */
}

/*
 * h_hup --
 *	Handle SIGHUP.
 */
static void
h_hup(signo)
	int signo;
{
	F_SET(__global_list, G_SIGHUP);

	/*
	 * If we're asleep, just die.
	 *
	 * XXX
	 * This isn't right if the windows are independent.
	 */
	if (F_ISSET(__global_list, G_SLEEPING))
		rcv_hup();
}

/*
 * h_term --
 *	Handle SIGTERM.
 */
static void
h_term(signo)
	int signo;
{
	F_SET(__global_list, G_SIGTERM);

	/*
	 * If we're asleep, just die.
	 *
	 * XXX
	 * This isn't right if the windows are independent.
	 */
	if (F_ISSET(__global_list, G_SLEEPING))
		rcv_term();
}

/*
 * h_winch --
 *	Handle SIGWINCH.
 */
static void
h_winch(signo)
	int signo;
{
	F_SET(__global_list, G_SIGWINCH);
}

/*
 * exrc_isok --
 *	Check a .exrc file for source-ability.
 *
 * !!!
 * Historically, vi read both $HOME and local .exrc file if they were owned
 * by the user's real ID, or the "sourceany" option was set, regardless of
 * any other considerations.  We no longer support the sourceany option as
 * it's a security problem of mammoth proportions.  We require that the file
 * be owned by root (for the system .exrc files) or the user's effective ID
 * (for any of the .exrc files), and require that it not be writeable by
 * anyone other than the owner.
 * 
 * In O'Reilly ("Learning the VI Editor", Fifth Ed., May 1992, page 106),
 * it notes that System V release 3.2 and later has an option "[no]exrc".
 * The behavior is that local .exrc files are read only if the exrc option
 * is set.  The default for the exrc option was off, so, by default, local
 * .exrc files were not read.  The problem this was intended to solve was
 * that System V permitted users to give away files, so there's no possible
 * ownership/writeability test that the file is safe.
 * 
 * POSIX 1003.2-1992 standardized exrc as an option.  It required the exrc
 * option to be off by default, thus local .exrc files are not to be read
 * by default.  The Rationale noted (incorrectly) that this was a change
 * to historic practice, but correctly noted that a default of off improves
 * system security.  POSIX also required that vi check the effective user
 * ID instead of the real user ID, which is why we've switched from historic
 * practice.
 * 
 * We initialize the exrc variable to off.  If it's turned on by the system
 * or $HOME .exrc files, and the local .exrc file passes the ownership and
 * writeability tests, then we read it.  This breaks historic 4BSD practice,
 * but it gives us a measure of security on systems where users can give away
 * files.
 */
static enum rc
exrc_isok(sp, sbp, path, rootok)
	SCR *sp;
	struct stat *sbp;
	char *path;
	int rootok;
{
	uid_t uid;
	char *emsg, buf[MAXPATHLEN];

	/* Check for the file's existence. */
	if (stat(path, sbp))
		return (NOEXIST);

	/* Owned by the user or root. */
	uid = geteuid();
	if (rootok) {
		if (sbp->st_uid != uid && sbp->st_uid != 0) {
			emsg = "not owned by you or root";
			goto denied;
		}
	} else
		if (sbp->st_uid != uid) {
			emsg = "not owned by you";
			goto denied;
		}

	/* Not writeable by anyone but the owner. */
	if (sbp->st_mode & (S_IWGRP | S_IWOTH)) {
		emsg = "writeable by a user other than the owner";
denied:		if (strchr(path, '/') == NULL &&
		    getcwd(buf, sizeof(buf)) != NULL)
			msgq(sp, M_ERR,
			    "%s/%s: not sourced: %s.", buf, path, emsg);
		else
			msgq(sp, M_ERR,
			    "%s: not sourced: %s.", path, emsg);
		return (NOPERM);
	}
	return (OK);
}

static void
obsolete(argv)
	char *argv[];
{
	size_t len;
	char *p;

	/*
	 * Translate old style arguments into something getopt will like.
	 * Make sure it's not text space memory, because ex changes the
	 * strings.
	 *	Change "+" into "-c$".
	 *	Change "+<anything else>" into "-c<anything else>".
	 *	Change "-" into "-s"
	 *	Change "-r" into "-l"
	 */
	while (*++argv)
		if (argv[0][0] == '+') {
			if (argv[0][1] == '\0') {
				MALLOC_NOMSG(NULL, argv[0], char *, 4);
				if (argv[0] == NULL)
					err(1, NULL);
				(void)strcpy(argv[0], "-c$");
			} else  {
				p = argv[0];
				len = strlen(argv[0]);
				MALLOC_NOMSG(NULL, argv[0], char *, len + 2);
				if (argv[0] == NULL)
					err(1, NULL);
				argv[0][0] = '-';
				argv[0][1] = 'c';
				(void)strcpy(argv[0] + 2, p + 1);
			}
		} else if (argv[0][0] == '-') {
			if (argv[0][1] == 'r') {
				if (argv[0][2] == '\0' && argv[1] == NULL)
					argv[0][1] = 'l';
			} else if (argv[0][1] == '\0') {
				MALLOC_NOMSG(NULL, argv[0], char *, 3);
				if (argv[0] == NULL)
					err(1, NULL);
				(void)strcpy(argv[0], "-s");
			}
		}
}

static void
usage(is_ex)
	int is_ex;
{
#define	EX_USAGE \
	"usage: ex [-eFlRsv] [-c command] [-r file] [-t tag] [-w size] [-x aw]"
#define	VI_USAGE \
	"usage: vi [-eFlRv] [-c command] [-r file] [-t tag] [-w size] [-x aw]"

	(void)fprintf(stderr, "%s\n", is_ex ? EX_USAGE : VI_USAGE);
	exit(1);
}