C++ F_CLR函数代码示例

//.........这里部分代码省略.........
		 * and check the errno values.
		 */
		errno = 0;
		if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
			switch (flags & O_ACCMODE) {
			case O_RDONLY:
				F_SET(t, R_RDONLY);
				break;
			default:
				goto einval;
			}
slow:			if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
				goto err;
			F_SET(t, R_CLOSEFP);
			t->bt_irec =
			    F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
		} else {
			switch (flags & O_ACCMODE) {
			case O_RDONLY:
				F_SET(t, R_RDONLY);
				break;
			case O_RDWR:
				break;
			default:
				goto einval;
			}

			if (fstat(rfd, &sb))
				goto err;
			/*
			 * Kluge -- we'd like to test to see if the file is too
			 * big to mmap.  Since, we don't know what size or type
			 * off_t's or size_t's are, what the largest unsigned
			 * integral type is, or what random insanity the local
			 * C compiler will perpetrate, doing the comparison in
			 * a portable way is flatly impossible.  Hope that mmap
			 * fails if the file is too large.
			 */
			if (sb.st_size == 0)
				F_SET(t, R_EOF);
			else {
#ifdef MMAP_NOT_AVAILABLE
				/*
				 * XXX
				 * Mmap doesn't work correctly on many current
				 * systems.  In particular, it can fail subtly,
				 * with cache coherency problems.  Don't use it
				 * for now.
				 */
				t->bt_msize = sb.st_size;
				if ((t->bt_smap = mmap(NULL, t->bt_msize,
				    PROT_READ, MAP_FILE | MAP_PRIVATE, rfd,
				    (off_t)0)) == (caddr_t)-1)
					goto slow;
				t->bt_cmap = t->bt_smap;
				t->bt_emap = t->bt_smap + sb.st_size;
				t->bt_irec = F_ISSET(t, R_FIXLEN) ?
				    __rec_fmap : __rec_vmap;
				F_SET(t, R_MEMMAPPED);
#else
				goto slow;
#endif
			}
		}
	}

	/* Use the recno routines. */
	dbp->close = __rec_close;
	dbp->del = __rec_delete;
	dbp->fd = __rec_fd;
	dbp->get = __rec_get;
	dbp->put = __rec_put;
	dbp->seq = __rec_seq;
	dbp->sync = __rec_sync;

	/* If the root page was created, reset the flags. */
	if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
		goto err;
	if ((h->flags & P_TYPE) == P_BLEAF) {
		F_CLR(h, P_TYPE);
		F_SET(h, P_RLEAF);
		mpool_put(t->bt_mp, h, MPOOL_DIRTY);
	} else
		mpool_put(t->bt_mp, h, 0);

	if (openinfo && openinfo->flags & R_SNAPSHOT &&
	    !F_ISSET(t, R_EOF | R_INMEM) &&
	    t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
                goto err;
	return (dbp);

einval:	errno = EINVAL;
err:	sverrno = errno;
	if (dbp != NULL)
		(void)__bt_close(dbp);
	if (fname != NULL)
		(void)close(rfd);
	errno = sverrno;
	return (NULL);
}

//.........这里部分代码省略.........
		 */
		F_SET(sp, SC_EX_WAIT_YES);

		/*
		 * !!!
		 * Ignore the return cursor position, the cursor doesn't
		 * move.
		 */
		if (ex_filter(sp, cmdp, &cmdp->addr1,
		    &cmdp->addr2, &rm, cmdp->argv[1]->bp, FILTER_WRITE))
			return (1);

		/* Ex terminates with a bang, even if the command fails. */
		if (!F_ISSET(sp, SC_VI) && !F_ISSET(sp, SC_EX_SILENT))
			(void)ex_puts(sp, "!\n");

		return (0);
	}

	/* Set the FS_ALL flag if we're writing the entire file. */
	if (cmdp->addr1.lno <= 1 && !db_exist(sp, cmdp->addr2.lno + 1))
		LF_SET(FS_ALL);

	/* If "write >>" it's an append to a file. */
	if (cmdp->argc != 0 && cmd != XIT && p[0] == '>' && p[1] == '>') {
		LF_SET(FS_APPEND);

		/* Skip ">>" and whitespace. */
		for (p += 2; *p && cmdskip(*p); ++p);
	}

	/* If no other arguments, just write the file back. */
	if (cmdp->argc == 0 || *p == '\0')
		return (file_write(sp,
		    &cmdp->addr1, &cmdp->addr2, NULL, flags));

	/* Build an argv so we get an argument count and file expansion. */
	if (argv_exp2(sp, cmdp, p, STRLEN(p)))
		return (1);

	/*
	 *  0 args: impossible.
	 *  1 args: impossible (I hope).
	 *  2 args: read it.
	 * >2 args: object, too many args.
	 *
	 * The 1 args case depends on the argv_sexp() function refusing
	 * to return success without at least one non-blank character.
	 */
	switch (cmdp->argc) {
	case 0:
	case 1:
		abort();
		/* NOTREACHED */
	case 2:
		INT2CHAR(sp, cmdp->argv[1]->bp, cmdp->argv[1]->len+1,
			 n, nlen);
		name = v_strdup(sp, n, nlen - 1);

		/*
		 * !!!
		 * Historically, the read and write commands renamed
		 * "unnamed" files, or, if the file had a name, set
		 * the alternate file name.
		 */
		if (F_ISSET(sp->frp, FR_TMPFILE) &&
		    !F_ISSET(sp->frp, FR_EXNAMED)) {
			if ((n = v_strdup(sp, name, nlen - 1)) != NULL) {
				free(sp->frp->name);
				sp->frp->name = n;
			}
			/*
			 * The file has a real name, it's no longer a
			 * temporary, clear the temporary file flags.
			 *
			 * !!!
			 * If we're writing the whole file, FR_NAMECHANGE
			 * will be cleared by the write routine -- this is
			 * historic practice.
			 */
			F_CLR(sp->frp, FR_TMPEXIT | FR_TMPFILE);
			F_SET(sp->frp, FR_NAMECHANGE | FR_EXNAMED);

			/* Notify the screen. */
			(void)sp->gp->scr_rename(sp, sp->frp->name, 1);
		} else
			set_alt_name(sp, name);
		break;
	default:
		INT2CHAR(sp, p, STRLEN(p) + 1, n, nlen);
		ex_emsg(sp, n, EXM_FILECOUNT);
		return (1);
	}

	rc = file_write(sp, &cmdp->addr1, &cmdp->addr2, name, flags);

	free(name);

	return rc;
}

//.........这里部分代码省略.........
		}

		if ((t->bt_fd = _open(fname, flags, mode)) < 0)
			goto err;

	} else {
		if ((flags & O_ACCMODE) != O_RDWR)
			goto einval;
		if ((t->bt_fd = tmp()) == -1)
			goto err;
		F_SET(t, B_INMEM);
	}

	if (_fcntl(t->bt_fd, F_SETFD, 1) == -1)
		goto err;

	if (_fstat(t->bt_fd, &sb))
		goto err;
	if (sb.st_size) {
		if ((nr = _read(t->bt_fd, &m, sizeof(BTMETA))) < 0)
			goto err;
		if (nr != sizeof(BTMETA))
			goto eftype;

		/*
		 * Read in the meta-data.  This can change the notion of what
		 * the lorder, page size and flags are, and, when the page size
		 * changes, the cachesize value can change too.  If the user
		 * specified the wrong byte order for an existing database, we
		 * don't bother to return an error, we just clear the NEEDSWAP
		 * bit.
		 */
		if (m.magic == BTREEMAGIC)
			F_CLR(t, B_NEEDSWAP);
		else {
			F_SET(t, B_NEEDSWAP);
			M_32_SWAP(m.magic);
			M_32_SWAP(m.version);
			M_32_SWAP(m.psize);
			M_32_SWAP(m.free);
			M_32_SWAP(m.nrecs);
			M_32_SWAP(m.flags);
		}
		if (m.magic != BTREEMAGIC || m.version != BTREEVERSION)
			goto eftype;
		if (m.psize < MINPSIZE || m.psize > MAX_PAGE_OFFSET + 1 ||
		    m.psize & (sizeof(indx_t) - 1) )
			goto eftype;
		if (m.flags & ~SAVEMETA)
			goto eftype;
		b.psize = m.psize;
		F_SET(t, m.flags);
		t->bt_free = m.free;
		t->bt_nrecs = m.nrecs;
	} else {
		/*
		 * Set the page size to the best value for I/O to this file.
		 * Don't overflow the page offset type.
		 */
		if (b.psize == 0) {
			b.psize = sb.st_blksize;
			if (b.psize < MINPSIZE)
				b.psize = MINPSIZE;
			if (b.psize > MAX_PAGE_OFFSET + 1)
				b.psize = MAX_PAGE_OFFSET + 1;
		}

/*
 * vs_output --
 *	Output the text to the screen.
 */
static void
vs_output(SCR *sp, mtype_t mtype, const char *line, int llen)
{
	unsigned char *kp;
	GS *gp;
	VI_PRIVATE *vip;
	size_t chlen, notused;
	int ch, len, rlen, tlen;
	const char *p, *t;
	char *cbp, *ecbp, cbuf[128];

	gp = sp->gp;
	vip = VIP(sp);
	for (p = line, rlen = llen; llen > 0;) {
		/* Get the next physical line. */
		if ((p = memchr(line, '\n', llen)) == NULL)
			len = llen;
		else
			len = p - line;

		/*
		 * The max is sp->cols characters, and we may have already
		 * written part of the line.
		 */
		if (len + vip->lcontinue > sp->cols)
			len = sp->cols - vip->lcontinue;

		/*
		 * If the first line output, do nothing.  If the second line
		 * output, draw the divider line.  If drew a full screen, we
		 * remove the divider line.  If it's a continuation line, move
		 * to the continuation point, else, move the screen up.
		 */
		if (vip->lcontinue == 0) {
			if (!IS_ONELINE(sp)) {
				if (vip->totalcount == 1) {
					(void)gp->scr_move(sp,
					    LASTLINE(sp) - 1, 0);
					(void)gp->scr_clrtoeol(sp);
					(void)vs_divider(sp);
					F_SET(vip, VIP_DIVIDER);
					++vip->totalcount;
					++vip->linecount;
				}
				if (vip->totalcount == sp->t_maxrows &&
				    F_ISSET(vip, VIP_DIVIDER)) {
					--vip->totalcount;
					--vip->linecount;
					F_CLR(vip, VIP_DIVIDER);
				}
			}
			if (vip->totalcount != 0)
				vs_scroll(sp, NULL, SCROLL_W_QUIT);

			(void)gp->scr_move(sp, LASTLINE(sp), 0);
			++vip->totalcount;
			++vip->linecount;

			if (INTERRUPTED(sp))
				break;
		} else
			(void)gp->scr_move(sp, LASTLINE(sp), vip->lcontinue);

		/* Error messages are in inverse video. */
		if (mtype == M_ERR)
			(void)gp->scr_attr(sp, SA_INVERSE, 1);

		/* Display the line, doing character translation. */
#define	FLUSH {								\
	*cbp = '\0';							\
	(void)gp->scr_addstr(sp, cbuf, cbp - cbuf);			\
	cbp = cbuf;							\
}
		ecbp = (cbp = cbuf) + sizeof(cbuf) - 1;
		for (t = line, tlen = len; tlen--; ++t) {
			ch = *t;
			/*
			 * Replace tabs with spaces, there are places in
			 * ex that do column calculations without looking
			 * at <tabs> -- and all routines that care about
			 * <tabs> do their own expansions.  This catches
			 * <tabs> in things like tag search strings.
			 */
			if (ch == '\t')
				ch = ' ';
			chlen = KEY_LEN(sp, ch);
			if (cbp + chlen >= ecbp)
				FLUSH;
			for (kp = KEY_NAME(sp, ch); chlen--;)
				*cbp++ = *kp++;
		}
		if (cbp > cbuf)
			FLUSH;
		if (mtype == M_ERR)
			(void)gp->scr_attr(sp, SA_INVERSE, 0);

//.........这里部分代码省略.........

/*
 * vs_resolve --
 *	Deal with message output.
 *
 * PUBLIC: int vs_resolve __P((SCR *, SCR *, int));
 */
int
vs_resolve(SCR *sp, SCR *csp, int forcewait)
{
	EVENT ev;
	GS *gp;
	WIN *wp;
	MSGS *mp;
	VI_PRIVATE *vip;
	size_t oldy, oldx;
	int redraw;

	/*
	 * Vs_resolve is called from the main vi loop and the refresh function
	 * to periodically ensure that the user has seen any messages that have
	 * been displayed and that any status lines are correct.  The sp screen
	 * is the screen we're checking, usually the current screen.  When it's
	 * not, csp is the current screen, used for final cursor positioning.
	 */
	gp = sp->gp;
	wp = sp->wp;
	vip = VIP(sp);
	if (csp == NULL)
		csp = sp;

	/* Save the cursor position. */
	(void)gp->scr_cursor(csp, &oldy, &oldx);

	/* Ring the bell if it's scheduled. */
	if (F_ISSET(gp, G_BELLSCHED)) {
		F_CLR(gp, G_BELLSCHED);
		(void)gp->scr_bell(sp);
	}

	/* Display new file status line. */
	if (F_ISSET(sp, SC_STATUS)) {
		F_CLR(sp, SC_STATUS);
		msgq_status(sp, sp->lno, MSTAT_TRUNCATE);
	}

	/* Report on line modifications. */
	mod_rpt(sp);

	/*
	 * Flush any saved messages.  If the screen isn't ready, refresh
	 * it.  (A side-effect of screen refresh is that we can display
	 * messages.)  Once this is done, don't trust the cursor.  That
	 * extra refresh screwed the pooch.
	 */
	if (gp->msgq.lh_first != NULL) {
		if (!F_ISSET(sp, SC_SCR_VI) && vs_refresh(sp, 1))
			return (1);
		while ((mp = gp->msgq.lh_first) != NULL) {
			wp->scr_msg(sp, mp->mtype, mp->buf, mp->len);
			LIST_REMOVE(mp, q);
			free(mp->buf);
			free(mp);
		}
		F_SET(vip, VIP_CUR_INVALID);
	}

	switch (vip->totalcount) {
	case 0:
		redraw = 0;
		break;
	case 1:
		/*
		 * If we're switching screens, we have to wait for messages,
		 * regardless.  If we don't wait, skip updating the modeline.
		 */
		if (forcewait)
			vs_scroll(sp, NULL, SCROLL_W);
		else
			F_SET(vip, VIP_S_MODELINE);

		redraw = 0;
		break;
	default:
		/*
		 * If >1 message line in use, prompt the user to continue and
		 * repaint overwritten lines.
		 */
		vs_scroll(sp, NULL, SCROLL_W);

		ev.e_event = E_REPAINT;
		ev.e_flno = vip->totalcount >=
		    sp->rows ? 1 : sp->rows - vip->totalcount;
		ev.e_tlno = sp->rows;

		redraw = 1;
		break;
	}

	/* Reset the count of overwriting lines. */
	vip->linecount = vip->lcontinue = vip->totalcount = 0;
//.........这里部分代码省略.........

/*
 * cl_vi_init --
 *	Initialize the curses vi screen.
 */
static int
cl_vi_init(SCR *sp)
{
	CL_PRIVATE *clp;
	char *o_cols, *o_lines, *o_term;
	const char *ttype;

	clp = CLP(sp);

	/* If already initialized, just set the terminal modes. */
	if (F_ISSET(clp, CL_SCR_VI_INIT))
		goto fast;

	/* Curses vi always reads from (and writes to) a terminal. */
	if (!F_ISSET(clp, CL_STDIN_TTY) || !isatty(STDOUT_FILENO)) {
		msgq(sp, M_ERR,
		    "016|Vi's standard input and output must be a terminal");
		return (1);
	}

	/* We'll need a terminal type. */
	if (opts_empty(sp, O_TERM, 0))
		return (1);
	ttype = O_STR(sp, O_TERM);

	/*
	 * XXX
	 * Changing the row/column and terminal values is done by putting them
	 * into the environment, which is then read by curses.  What this loses
	 * in ugliness, it makes up for in stupidity.  We can't simply put the
	 * values into the environment ourselves, because in the presence of a
	 * kernel mechanism for returning the window size, entering values into
	 * the environment will screw up future screen resizing events, e.g. if
	 * the user enters a :shell command and then resizes their window.  So,
	 * if they weren't already in the environment, we make sure to delete
	 * them immediately after setting them.
	 *
	 * XXX
	 * Putting the TERM variable into the environment is necessary, even
	 * though we're using newterm() here.  We may be using initscr() as
	 * the underlying function.
	 */
	o_term = getenv("TERM");
	cl_putenv(sp, "TERM", ttype, 0);
	o_lines = getenv("LINES");
	cl_putenv(sp, "LINES", NULL, (u_long)O_VAL(sp, O_LINES));
	o_cols = getenv("COLUMNS");
	cl_putenv(sp, "COLUMNS", NULL, (u_long)O_VAL(sp, O_COLUMNS));

	/* Delete cur_term if exists. */
	if (F_ISSET(clp, CL_SETUPTERM)) {
		if (del_curterm(cur_term))
			return (1);
		F_CLR(clp, CL_SETUPTERM);
	}

	/*
	 * XXX
	 * The SunOS initscr() can't be called twice.  Don't even think about
	 * using it.  It fails in subtle ways (e.g. select(2) on fileno(stdin)
	 * stops working).  (The SVID notes that applications should only call
	 * initscr() once.)
	 *
	 * XXX
	 * The HP/UX newterm doesn't support the NULL first argument, so we
	 * have to specify the terminal type.
	 */
	errno = 0;
	if ((clp->screen = newterm(__UNCONST(ttype), stdout, stdin)) == NULL) {
		if (errno)
			msgq(sp, M_SYSERR, "%s", ttype);
		else
			msgq(sp, M_ERR, "%s: unknown terminal type", ttype);
		return (1);
	}

	if (o_term == NULL)
		cl_unsetenv(sp, "TERM");
	if (o_lines == NULL)
		cl_unsetenv(sp, "LINES");
	if (o_cols == NULL)
		cl_unsetenv(sp, "COLUMNS");

	/*
	 * XXX
	 * Someone got let out alone without adult supervision -- the SunOS
	 * newterm resets the signal handlers.  There's a race, but it's not
	 * worth closing.
	 */
	(void)sig_init(sp->gp, sp);

	/*
	 * We use raw mode.  What we want is 8-bit clean, however, signals
	 * and flow control should continue to work.  Admittedly, it sounds
	 * like cbreak, but it isn't.  Using cbreak() can get you additional
	 * things like IEXTEN, which turns on flags like DISCARD and LNEXT.
//.........这里部分代码省略.........

/*
 * cl_screen --
 *	Switch screen types.
 *
 * PUBLIC: int cl_screen __P((SCR *, u_int32_t));
 */
int
cl_screen(SCR *sp, u_int32_t flags)
{
	CL_PRIVATE *clp;
	WINDOW *win;
	GS *gp;
	int ret, error;
	sigset_t oset;

	gp = sp->gp;
	clp = CLP(sp);
	win = CLSP(sp) ? CLSP(sp) : stdscr;

	ret = 0;

	/*
	 * During initialization of the screen, block signals to make sure that
	 * curses/terminfo routines are not interrupted.
	 */
	error = sigprocmask(SIG_BLOCK, &__sigblockset, &oset);

	/* See if the current information is incorrect. */
	if (F_ISSET(gp, G_SRESTART)) {
		if (CLSP(sp)) {
		    delwin(CLSP(sp));
		    sp->cl_private = NULL;
		}
		if (cl_quit(gp)) {
			ret = 1;
			goto end;
		}
		F_CLR(gp, G_SRESTART);
	}
	
	/* See if we're already in the right mode. */
	if ((LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX)) ||
	    (LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI)))
		goto end;

	/*
	 * Fake leaving ex mode.
	 *
	 * We don't actually exit ex or vi mode unless forced (e.g. by a window
	 * size change).  This is because many curses implementations can't be
	 * called twice in a single program.  Plus, it's faster.  If the editor
	 * "leaves" vi to enter ex, when it exits ex we'll just fall back into
	 * vi.
	 */
	if (F_ISSET(sp, SC_SCR_EX))
		F_CLR(sp, SC_SCR_EX);

	/*
	 * Fake leaving vi mode.
	 *
	 * Clear out the rest of the screen if we're in the middle of a split
	 * screen.  Move to the last line in the current screen -- this makes
	 * terminal scrolling happen naturally.  Note: *don't* move past the
	 * end of the screen, as there are ex commands (e.g., :read ! cat file)
	 * that don't want to.  Don't clear the info line, its contents may be
	 * valid, e.g. :file|append.
	 */
	if (F_ISSET(sp, SC_SCR_VI)) {
		F_CLR(sp, SC_SCR_VI);

		if (TAILQ_NEXT(sp, q) != NULL) {
			(void)wmove(win, RLNO(sp, sp->rows), 0);
			wclrtobot(win);
		}
		(void)wmove(win, RLNO(sp, sp->rows) - 1, 0);
		wrefresh(win);
	}

	/* Enter the requested mode. */
	if (LF_ISSET(SC_EX)) {
		if (cl_ex_init(sp)) {
			ret = 1;
			goto end;
		}
		F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT);

		/*
		 * If doing an ex screen for ex mode, move to the last line
		 * on the screen.
		 */
		if (F_ISSET(sp, SC_EX) && clp->cup != NULL)
			tputs(tgoto(clp->cup,
			    0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar);
	} else {
		if (cl_vi_init(sp)) {
			ret = 1;
			goto end;
		}
		F_CLR(clp, CL_IN_EX);
		F_SET(clp, CL_SCR_VI_INIT);
//.........这里部分代码省略.........

//.........这里部分代码省略.........

	/* Pick up optional buffer. */
	if (key == '"') {
		cpart = ISPARTIAL;
		if (F_ISSET(vp, VC_BUFFER)) {
			msgq(sp, M_ERR, "234|Only one buffer may be specified");
			return (GC_ERR);
		}
		if (ismotion != NULL) {
			v_emsg(sp, NULL, VIM_COMBUF);
			return (GC_ERR);
		}
		KEY(vp->buffer, 0);
		F_SET(vp, VC_BUFFER);

		KEY(key, EC_MAPCOMMAND);
	}

	/* Check for an OOB command key. */
	cpart = ISPARTIAL;
	if (key > MAXVIKEY) {
		v_emsg(sp, KEY_NAME(sp, key), VIM_NOCOM);
		return (GC_ERR);
	}
	kp = &vikeys[vp->key = key];

	/*
	 * !!!
	 * Historically, D accepted and then ignored a count.  Match it.
	 */
	if (vp->key == 'D' && F_ISSET(vp, VC_C1SET)) {
		*comcountp = 0;
		vp->count = 0;
		F_CLR(vp, VC_C1SET);
	}

	/* Check for command aliases. */
	if (kp->func == NULL && (kp = v_alias(sp, vp, kp)) == NULL)
		return (GC_ERR);

	/* The tildeop option makes the ~ command take a motion. */
	if (key == '~' && O_ISSET(sp, O_TILDEOP))
		kp = &tmotion;

	vp->kp = kp;

	/*
	 * Find the command.  The only legal command with no underlying
	 * function is dot.  It's historic practice that <escape> doesn't
	 * just erase the preceding number, it beeps the terminal as well.
	 * It's a common problem, so just beep the terminal unless verbose
	 * was set.
	 */
	if (kp->func == NULL) {
		if (key != '.') {
			v_emsg(sp, KEY_NAME(sp, key),
			    ev.e_value == K_ESCAPE ? VIM_NOCOM_B : VIM_NOCOM);
			return (GC_ERR);
		}

		/* If called for a motion command, stop now. */
		if (dp == NULL)
			goto usage;

		/*
		 * !!!

/*
 * vi --
 * 	Main vi command loop.
 *
 * PUBLIC: int vi __P((SCR **));
 */
int
vi(SCR **spp)
{
	GS *gp;
	MARK abs;
	SCR *next, *sp;
	VICMD cmd = { 0 }, *vp;
	VI_PRIVATE *vip;
	int comcount, mapped, rval;

	/* Get the first screen. */
	sp = *spp;
	gp = sp->gp;

	/* Point to the command structure. */
	vp = &cmd;

	/* Reset strange attraction. */
	F_SET(vp, VM_RCM_SET);

	/* Initialize the vi screen. */
	if (v_init(sp))
		return (1);

	/* Set the focus. */
	(void)sp->gp->scr_rename(sp, sp->frp->name, 1);

	for (vip = VIP(sp), rval = 0;;) {
		/* Resolve messages. */
		if (!MAPPED_KEYS_WAITING(sp) && vs_resolve(sp, NULL, 0))
			goto ret;

		/*
		 * If not skipping a refresh, return to command mode and
		 * refresh the screen.
		 */
		if (F_ISSET(vip, VIP_S_REFRESH))
			F_CLR(vip, VIP_S_REFRESH);
		else {
			sp->showmode = SM_COMMAND;
			if (vs_refresh(sp, 0))
				goto ret;
		}

		/* Set the new favorite position. */
		if (F_ISSET(vp, VM_RCM_SET | VM_RCM_SETFNB | VM_RCM_SETNNB)) {
			F_CLR(vip, VIP_RCM_LAST);
			(void)vs_column(sp, &sp->rcm);
		}

		/*
		 * If not currently in a map, log the cursor position,
		 * and set a flag so that this command can become the
		 * DOT command.
		 */
		if (MAPPED_KEYS_WAITING(sp))
			mapped = 1;
		else {
			if (log_cursor(sp))
				goto err;
			mapped = 0;
		}

		/*
		 * There may be an ex command waiting, and we returned here
		 * only because we exited a screen or file.  In this case,
		 * we simply go back into the ex parser.
		 */
		if (EXCMD_RUNNING(gp)) {
			vp->kp = &vikeys[':'];
			goto ex_continue;
		}

		/* Refresh the command structure. */
		memset(vp, 0, sizeof(VICMD));

		/*
		 * We get a command, which may or may not have an associated
		 * motion.  If it does, we get it too, calling its underlying
		 * function to get the resulting mark.  We then call the
		 * command setting the cursor to the resulting mark.
		 *
		 * !!!
		 * Vi historically flushed mapped characters on error, but
		 * entering extra <escape> characters at the beginning of
		 * a map wasn't considered an error -- in fact, users would
		 * put leading <escape> characters in maps to clean up vi
		 * state before the map was interpreted.  Beauty!
		 */
		switch (v_cmd(sp, DOT, vp, NULL, &comcount, &mapped)) {
		case GC_ERR:
			goto err;
		case GC_ERR_NOFLUSH:
			goto gc_err_noflush;
//.........这里部分代码省略.........

/*
 * rcv_sync --
 *	Sync the file, optionally:
 *		flagging the backup file to be preserved
 *		snapshotting the backup file and send email to the user
 *		sending email to the user if the file was modified
 *		ending the file session
 *
 * PUBLIC: int rcv_sync __P((SCR *, u_int));
 */
int
rcv_sync(SCR *sp, u_int flags)
{
	EXF *ep;
	int fd, rval;
	char buf[1024];
	const char *dp;

	/* Make sure that there's something to recover/sync. */
	ep = sp->ep;
	if (ep == NULL || !F_ISSET(ep, F_RCV_ON))
		return (0);

	/* Sync the file if it's been modified. */
	if (F_ISSET(ep, F_MODIFIED)) {
		/*
		 * If we are using a db1 version of the database,
		 * we want to sync the underlying btree not the
		 * recno tree which is transient anyway.
		 */
#ifndef R_RECNOSYNC
#define	R_RECNOSYNC 0
#endif
		if (ep->db->sync(ep->db, R_RECNOSYNC)) {
			F_CLR(ep, F_RCV_ON | F_RCV_NORM);
			msgq_str(sp, M_SYSERR,
			    ep->rcv_path, "060|File backup failed: %s");
			return (1);
		}

		/* REQUEST: don't remove backing file on exit. */
		if (LF_ISSET(RCV_PRESERVE))
			F_SET(ep, F_RCV_NORM);

		/* REQUEST: send email. */
		if (LF_ISSET(RCV_EMAIL))
			rcv_email(sp, ep->rcv_mpath);
	}

	/*
	 * !!!
	 * Each time the user exec's :preserve, we have to snapshot all of
	 * the recovery information, i.e. it's like the user re-edited the
	 * file.  We copy the DB(3) backing file, and then create a new mail
	 * recovery file, it's simpler than exiting and reopening all of the
	 * underlying files.
	 *
	 * REQUEST: snapshot the file.
	 */
	rval = 0;
	if (LF_ISSET(RCV_SNAPSHOT)) {
		if (opts_empty(sp, O_RECDIR, 0))
			goto err;
		dp = O_STR(sp, O_RECDIR);
		(void)snprintf(buf, sizeof(buf), "%s/vi.XXXXXX", dp);
		if ((fd = rcv_mktemp(sp, buf, dp, S_IRUSR | S_IWUSR)) == -1)
			goto err;
		sp->gp->scr_busy(sp,
		    "061|Copying file for recovery...", BUSY_ON);
		if (rcv_copy(sp, fd, ep->rcv_path) ||
		    close(fd) || rcv_mailfile(sp, 1, buf)) {
			(void)unlink(buf);
			(void)close(fd);
			rval = 1;
		}
		sp->gp->scr_busy(sp, NULL, BUSY_OFF);
	}
	if (0) {
err:		rval = 1;
	}

	/* REQUEST: end the file session. */
	if (LF_ISSET(RCV_ENDSESSION) && file_end(sp, NULL, 1))
		rval = 1;

	return (rval);
}

/*
 * __rec_page_dirty_update --
 *	Update a dirty page's reference on eviction.
 */
static int
__rec_page_dirty_update(
    WT_SESSION_IMPL *session, WT_REF *parent_ref, WT_PAGE *page)
{
	WT_ADDR *addr;
	WT_PAGE_MODIFY *mod;

	mod = page->modify;
	switch (F_ISSET(mod, WT_PM_REC_MASK)) {
	case WT_PM_REC_EMPTY:				/* Page is empty */
		if (parent_ref->addr != NULL &&
		    __wt_off_page(page->parent, parent_ref->addr)) {
			__wt_free(session, ((WT_ADDR *)parent_ref->addr)->addr);
			__wt_free(session, parent_ref->addr);
		}

		/*
		 * Update the parent to reference an empty page.
		 *
		 * Set the transaction ID to WT_TXN_NONE because the fact that
		 * reconciliation left the page "empty" means there's no older
		 * transaction in the system that might need to see an earlier
		 * version of the page.  It isn't necessary (WT_TXN_NONE is 0),
		 * but it's the right thing to do.
		 *
		 * Publish: a barrier to ensure the structure fields are set
		 * before the state change makes the page available to readers.
		 */
		parent_ref->page = NULL;
		parent_ref->addr = NULL;
		parent_ref->txnid = WT_TXN_NONE;
		WT_PUBLISH(parent_ref->state, WT_REF_DELETED);
		break;
	case WT_PM_REC_REPLACE: 			/* 1-for-1 page swap */
		if (parent_ref->addr != NULL &&
		    __wt_off_page(page->parent, parent_ref->addr)) {
			__wt_free(session, ((WT_ADDR *)parent_ref->addr)->addr);
			__wt_free(session, parent_ref->addr);
		}

		/*
		 * Update the parent to reference the replacement page.
		 *
		 * Publish: a barrier to ensure the structure fields are set
		 * before the state change makes the page available to readers.
		 */
		WT_RET(__wt_calloc(session, 1, sizeof(WT_ADDR), &addr));
		*addr = mod->u.replace;
		mod->u.replace.addr = NULL;
		mod->u.replace.size = 0;

		parent_ref->page = NULL;
		parent_ref->addr = addr;
		WT_PUBLISH(parent_ref->state, WT_REF_DISK);
		break;
	case WT_PM_REC_SPLIT:				/* Page split */
		/*
		 * Update the parent to reference new internal page(s).
		 *
		 * Publish: a barrier to ensure the structure fields are set
		 * before the state change makes the page available to readers.
		 */
		parent_ref->page = mod->u.split;
		WT_PUBLISH(parent_ref->state, WT_REF_MEM);

		/* Clear the page else discarding the page will free it. */
		mod->u.split = NULL;
		F_CLR(mod, WT_PM_REC_SPLIT);
		break;
	WT_ILLEGAL_VALUE(session);
	}

	return (0);
}

/*
 * __wt_meta_track_off --
 *	Turn off metadata operation tracking, unrolling on error.
 */
int
__wt_meta_track_off(WT_SESSION_IMPL *session, bool need_sync, bool unroll)
{
	WT_DECL_RET;
	WT_META_TRACK *trk, *trk_orig;
	WT_SESSION_IMPL *ckpt_session;
	int saved_ret;
	bool did_drop;

	saved_ret = 0;

	WT_ASSERT(session,
	    WT_META_TRACKING(session) && session->meta_track_nest > 0);

	trk_orig = session->meta_track;
	trk = session->meta_track_next;

	/* If it was a nested transaction, there is nothing to do. */
	if (--session->meta_track_nest != 0)
		return (0);

	/* Turn off tracking for unroll. */
	session->meta_track_next = session->meta_track_sub = NULL;

	/*
	 * If there were no operations logged, skip unnecessary metadata
	 * checkpoints.  For example, this happens if attempting to create a
	 * data source that already exists (or drop one that doesn't).
	 */
	if (trk == trk_orig)
		goto err;

	/* Unrolling doesn't require syncing the metadata. */
	if (unroll)
		goto err;

	if (F_ISSET(session, WT_SESSION_SCHEMA_TXN)) {
		F_CLR(session, WT_SESSION_SCHEMA_TXN);
#ifdef WT_ENABLE_SCHEMA_TXN
		WT_ERR(__wt_txn_commit(session, NULL));
		__wt_errx(session, "TRACK: Commit internal schema txn");
#endif
	}

	/*
	 * If we don't have the metadata cursor (e.g, we're in the process of
	 * creating the metadata), we can't sync it.
	 */
	if (!need_sync || session->meta_cursor == NULL ||
	    F_ISSET(S2C(session), WT_CONN_IN_MEMORY))
		goto err;

	/* If we're logging, make sure the metadata update was flushed. */
	if (FLD_ISSET(S2C(session)->log_flags, WT_CONN_LOG_ENABLED))
		WT_WITH_DHANDLE(session,
		    WT_SESSION_META_DHANDLE(session),
		    ret = __wt_txn_checkpoint_log(
		    session, false, WT_TXN_LOG_CKPT_SYNC, NULL));
	else {
		WT_ASSERT(session, F_ISSET(session, WT_SESSION_LOCKED_SCHEMA));
		ckpt_session = S2C(session)->meta_ckpt_session;
		/*
		 * If this operation is part of a running transaction, that
		 * should be included in the checkpoint.
		 */
		ckpt_session->txn.id = session->txn.id;
		WT_ASSERT(session,
		    !F_ISSET(session, WT_SESSION_LOCKED_METADATA));
		WT_WITH_DHANDLE(ckpt_session, WT_SESSION_META_DHANDLE(session),
		    WT_WITH_METADATA_LOCK(ckpt_session,
			ret = __wt_checkpoint(ckpt_session, NULL)));
		ckpt_session->txn.id = WT_TXN_NONE;
		if (ret == 0)
			WT_WITH_DHANDLE(session,
			    WT_SESSION_META_DHANDLE(session),
			    ret = __wt_checkpoint_sync(session, NULL));
	}

err:	/*
	 * Undo any tracked operations on failure.
	 * Apply any tracked operations post-commit.
	 */
	did_drop = false;
	if (unroll || ret != 0) {
		saved_ret = ret;
		ret = 0;
		while (--trk >= trk_orig) {
			did_drop = did_drop || trk->op == WT_ST_DROP_COMMIT;
			WT_TRET(__meta_track_unroll(session, trk));
		}
	} else
		for (; trk_orig < trk; trk_orig++) {
			did_drop = did_drop ||
			    trk_orig->op == WT_ST_DROP_COMMIT;
			WT_TRET(__meta_track_apply(session, trk_orig));
		}
//.........这里部分代码省略.........

/*
 * __bt_seqadvance --
 *	Advance the sequential scan.
 *
 * Parameters:
 *	t:	tree
 *	flags:	R_NEXT, R_PREV
 *
 * Side effects:
 *	Pins the page the new key/data record is on.
 *
 * Returns:
 *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
 */
static int
__bt_seqadv(BTREE *t, EPG *ep, int flags)
{
	CURSOR *c;
	PAGE *h;
	indx_t idx;
	pgno_t pg;
	int exact;

	/*
	 * There are a couple of states that we can be in.  The cursor has
	 * been initialized by the time we get here, but that's all we know.
	 */
	c = &t->bt_cursor;

	/*
	 * The cursor was deleted where there weren't any duplicate records,
	 * so the key was saved.  Find out where that key would go in the
	 * current tree.  It doesn't matter if the returned key is an exact
	 * match or not -- if it's an exact match, the record was added after
	 * the delete so we can just return it.  If not, as long as there's
	 * a record there, return it.
	 */
	if (F_ISSET(c, CURS_ACQUIRE))
		return (__bt_first(t, &c->key, ep, &exact));

	/* Get the page referenced by the cursor. */
	if ((h = mpool_get(t->bt_mp, c->pg.pgno, 0)) == NULL)
		return (RET_ERROR);

	/*
	 * Find the next/previous record in the tree and point the cursor at
	 * it.  The cursor may not be moved until a new key has been found.
	 */
	switch (flags) {
	case R_NEXT:			/* Next record. */
		/*
		 * The cursor was deleted in duplicate records, and moved
		 * forward to a record that has yet to be returned.  Clear
		 * that flag, and return the record.
		 */
		if (F_ISSET(c, CURS_AFTER))
			goto usecurrent;
		idx = c->pg.index;
		if (++idx == NEXTINDEX(h)) {
			pg = h->nextpg;
			mpool_put(t->bt_mp, h, 0);
			if (pg == P_INVALID)
				return (RET_SPECIAL);
			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
				return (RET_ERROR);
			idx = 0;
		}
		break;
	case R_PREV:			/* Previous record. */
		/*
		 * The cursor was deleted in duplicate records, and moved
		 * backward to a record that has yet to be returned.  Clear
		 * that flag, and return the record.
		 */
		if (F_ISSET(c, CURS_BEFORE)) {
usecurrent:		F_CLR(c, CURS_AFTER | CURS_BEFORE);
			ep->page = h;
			ep->index = c->pg.index;
			return (RET_SUCCESS);
		}
		idx = c->pg.index;
		if (idx == 0) {
			pg = h->prevpg;
			mpool_put(t->bt_mp, h, 0);
			if (pg == P_INVALID)
				return (RET_SPECIAL);
			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
				return (RET_ERROR);
			idx = NEXTINDEX(h) - 1;
		} else
			--idx;
		break;
	}

	ep->page = h;
	ep->index = idx;
	return (RET_SUCCESS);
}

//.........这里部分代码省略.........
		return (1);
	
	/*
	 * Remember where any remaining command information is, and clean
	 * up the fake ex command.
	 */
	cmd = cmdp->cp;
	len = cmdp->clen;
	gp->excmd.clen = 0;

	if (err)
		goto err2;

	/* Copy out the new cursor position and make sure it's okay. */
	switch (cmdp->addrcnt) {
	case 1:
		vp->m_stop = cmdp->addr1;
		break;
	case 2:
		vp->m_stop = cmdp->addr2;
		break;
	}
	if (!db_exist(sp, vp->m_stop.lno)) {
		ex_badaddr(sp, &fake,
		    vp->m_stop.lno == 0 ? A_ZERO : A_EOF, NUM_OK);
		goto err2;
	}

	/*
	 * !!!
	 * Historic practice is that a trailing 'z' was ignored if it was a
	 * motion command.  Should probably be an error, but not worth the
	 * effort.
	 */
	if (ISMOTION(vp))
		return (v_correct(sp, vp, F_ISSET(cmdp, E_DELTA)));
		
	/*
	 * !!!
	 * Historically, if it wasn't a motion command, a delta in the search
	 * pattern turns it into a first nonblank movement.
	 */
	nb = F_ISSET(cmdp, E_DELTA);

	/* Check for the 'z' command. */
	if (len != 0) {
		if (*cmd != 'z')
			goto err1;

		/* No blanks, just like the z command. */
		for (t = cmd + 1, tlen = len - 1; tlen > 0; ++t, --tlen)
			if (!isdigit(*t))
				break;
		if (tlen &&
		    (*t == '-' || *t == '.' || *t == '+' || *t == '^')) {
			++t;
			--tlen;
			type = 1;
		} else
			type = 0;
		if (tlen)
			goto err1;

		/* The z command will do the nonblank for us. */
		nb = 0;

		/* Default to z+. */
		if (!type &&
		    v_event_push(sp, NULL, L("+"), 1, CH_NOMAP | CH_QUOTED))
			return (1);

		/* Push the user's command. */
		if (v_event_push(sp, NULL, cmd, len, CH_NOMAP | CH_QUOTED))
			return (1);

		/* Push line number so get correct z display. */
		tlen = snprintf(buf,
		    sizeof(buf), "%lu", (u_long)vp->m_stop.lno);
		CHAR2INT(sp, buf, tlen, w, wlen);
		if (v_event_push(sp, NULL, w, wlen, CH_NOMAP | CH_QUOTED))
			return (1);
		 
		/* Don't refresh until after 'z' happens. */
		F_SET(VIP(sp), VIP_S_REFRESH);
	}

	/* Non-motion commands move to the end of the range. */
	vp->m_final = vp->m_stop;
	if (nb) {
		F_CLR(vp, VM_RCM_MASK);
		F_SET(vp, VM_RCM_SETFNB);
	}
	return (0);

err1:	msgq(sp, M_ERR,
	    "188|Characters after search string, line offset and/or z command");
err2:	vp->m_final.lno = s_lno;
	vp->m_final.cno = s_cno;
	return (1);
}

/*
 * __wt_btcur_prev --
 *	Move to the previous record in the tree.
 */
int
__wt_btcur_prev(WT_CURSOR_BTREE *cbt)
{
	WT_DECL_RET;
	WT_SESSION_IMPL *session;
	int newpage;

	session = (WT_SESSION_IMPL *)cbt->iface.session;
	WT_BSTAT_INCR(session, cursor_read_prev);

	__cursor_func_init(cbt, 0);

	/*
	 * If we aren't already iterating in the right direction, there's
	 * some setup to do.
	 */
	if (!F_ISSET(cbt, WT_CBT_ITERATE_PREV))
		__wt_btcur_iterate_setup(cbt, 0);

	/*
	 * Walk any page we're holding until the underlying call returns not-
	 * found.  Then, move to the previous page, until we reach the start
	 * of the file.
	 */
	for (newpage = 0;; newpage = 1) {
		if (F_ISSET(cbt, WT_CBT_ITERATE_APPEND)) {
			switch (cbt->page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_append_prev(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_append_prev(cbt, newpage);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}
			if (ret == 0)
				break;
			F_CLR(cbt, WT_CBT_ITERATE_APPEND);
			if (ret != WT_NOTFOUND)
				break;
			newpage = 1;
		}
		if (cbt->page != NULL) {
			switch (cbt->page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_prev(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_prev(cbt, newpage);
				break;
			case WT_PAGE_ROW_LEAF:
				ret = __cursor_row_prev(cbt, newpage);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}
			if (ret != WT_NOTFOUND)
				break;
		}

		do {
			WT_ERR(__wt_tree_np(session, &cbt->page, 0, 0));
			WT_ERR_TEST(cbt->page == NULL, WT_NOTFOUND);
		} while (
		    cbt->page->type == WT_PAGE_COL_INT ||
		    cbt->page->type == WT_PAGE_ROW_INT);

		/*
		 * The last page in a column-store has appended entries.
		 * We handle it separately from the usual cursor code:
		 * it's only that one page and it's in a simple format.
		 */
		if (cbt->page->type != WT_PAGE_ROW_LEAF &&
		    (cbt->ins_head = WT_COL_APPEND(cbt->page)) != NULL)
			F_SET(cbt, WT_CBT_ITERATE_APPEND);
	}

err:	__cursor_func_resolve(cbt, ret);
	return (ret);
}