xref: /freebsd/contrib/nvi/vi/v_txt.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*-
2  * Copyright (c) 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "@(#)v_txt.c	10.87 (Berkeley) 10/13/96";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 #include <sys/stat.h>
19 #include <sys/time.h>
20 
21 #include <bitstring.h>
22 #include <ctype.h>
23 #include <errno.h>
24 #include <limits.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29 
30 #include "../common/common.h"
31 #include "vi.h"
32 
33 static int	 txt_abbrev __P((SCR *, TEXT *, CHAR_T *, int, int *, int *));
34 static void	 txt_ai_resolve __P((SCR *, TEXT *, int *));
35 static TEXT	*txt_backup __P((SCR *, TEXTH *, TEXT *, u_int32_t *));
36 static int	 txt_dent __P((SCR *, TEXT *, int));
37 static int	 txt_emark __P((SCR *, TEXT *, size_t));
38 static void	 txt_err __P((SCR *, TEXTH *));
39 static int	 txt_fc __P((SCR *, TEXT *, int *));
40 static int	 txt_fc_col __P((SCR *, int, ARGS **));
41 static int	 txt_hex __P((SCR *, TEXT *));
42 static int	 txt_insch __P((SCR *, TEXT *, CHAR_T *, u_int));
43 static int	 txt_isrch __P((SCR *, VICMD *, TEXT *, u_int8_t *));
44 static int	 txt_map_end __P((SCR *));
45 static int	 txt_map_init __P((SCR *));
46 static int	 txt_margin __P((SCR *, TEXT *, TEXT *, int *, u_int32_t));
47 static void	 txt_nomorech __P((SCR *));
48 static void	 txt_Rresolve __P((SCR *, TEXTH *, TEXT *, const size_t));
49 static int	 txt_resolve __P((SCR *, TEXTH *, u_int32_t));
50 static int	 txt_showmatch __P((SCR *, TEXT *));
51 static void	 txt_unmap __P((SCR *, TEXT *, u_int32_t *));
52 
53 /* Cursor character (space is hard to track on the screen). */
54 #if defined(DEBUG) && 0
55 #undef	CH_CURSOR
56 #define	CH_CURSOR	'+'
57 #endif
58 
59 /*
60  * v_tcmd --
61  *	Fill a buffer from the terminal for vi.
62  *
63  * PUBLIC: int v_tcmd __P((SCR *, VICMD *, ARG_CHAR_T, u_int));
64  */
65 int
66 v_tcmd(sp, vp, prompt, flags)
67 	SCR *sp;
68 	VICMD *vp;
69 	ARG_CHAR_T prompt;
70 	u_int flags;
71 {
72 	/* Normally, we end up where we started. */
73 	vp->m_final.lno = sp->lno;
74 	vp->m_final.cno = sp->cno;
75 
76 	/* Initialize the map. */
77 	if (txt_map_init(sp))
78 		return (1);
79 
80 	/* Move to the last line. */
81 	sp->lno = TMAP[0].lno;
82 	sp->cno = 0;
83 
84 	/* Don't update the modeline for now. */
85 	F_SET(sp, SC_TINPUT_INFO);
86 
87 	/* Set the input flags. */
88 	LF_SET(TXT_APPENDEOL |
89 	    TXT_CR | TXT_ESCAPE | TXT_INFOLINE | TXT_MAPINPUT);
90 	if (O_ISSET(sp, O_ALTWERASE))
91 		LF_SET(TXT_ALTWERASE);
92 	if (O_ISSET(sp, O_TTYWERASE))
93 		LF_SET(TXT_TTYWERASE);
94 
95 	/* Do the input thing. */
96 	if (v_txt(sp, vp, NULL, NULL, 0, prompt, 0, 1, flags))
97 		return (1);
98 
99 	/* Reenable the modeline updates. */
100 	F_CLR(sp, SC_TINPUT_INFO);
101 
102 	/* Clean up the map. */
103 	if (txt_map_end(sp))
104 		return (1);
105 
106 	if (IS_ONELINE(sp))
107 		F_SET(sp, SC_SCR_REDRAW);	/* XXX */
108 
109 	/* Set the cursor to the resulting position. */
110 	sp->lno = vp->m_final.lno;
111 	sp->cno = vp->m_final.cno;
112 
113 	return (0);
114 }
115 
116 /*
117  * txt_map_init
118  *	Initialize the screen map for colon command-line input.
119  */
120 static int
121 txt_map_init(sp)
122 	SCR *sp;
123 {
124 	SMAP *esmp;
125 	VI_PRIVATE *vip;
126 
127 	vip = VIP(sp);
128 	if (!IS_ONELINE(sp)) {
129 		/*
130 		 * Fake like the user is doing input on the last line of the
131 		 * screen.  This makes all of the scrolling work correctly,
132 		 * and allows us the use of the vi text editing routines, not
133 		 * to mention practically infinite length ex commands.
134 		 *
135 		 * Save the current location.
136 		 */
137 		vip->sv_tm_lno = TMAP->lno;
138 		vip->sv_tm_soff = TMAP->soff;
139 		vip->sv_tm_coff = TMAP->coff;
140 		vip->sv_t_maxrows = sp->t_maxrows;
141 		vip->sv_t_minrows = sp->t_minrows;
142 		vip->sv_t_rows = sp->t_rows;
143 
144 		/*
145 		 * If it's a small screen, TMAP may be small for the screen.
146 		 * Fix it, filling in fake lines as we go.
147 		 */
148 		if (IS_SMALL(sp))
149 			for (esmp =
150 			    HMAP + (sp->t_maxrows - 1); TMAP < esmp; ++TMAP) {
151 				TMAP[1].lno = TMAP[0].lno + 1;
152 				TMAP[1].coff = HMAP->coff;
153 				TMAP[1].soff = 1;
154 			}
155 
156 		/* Build the fake entry. */
157 		TMAP[1].lno = TMAP[0].lno + 1;
158 		TMAP[1].soff = 1;
159 		TMAP[1].coff = 0;
160 		SMAP_FLUSH(&TMAP[1]);
161 		++TMAP;
162 
163 		/* Reset the screen information. */
164 		sp->t_rows = sp->t_minrows = ++sp->t_maxrows;
165 	}
166 	return (0);
167 }
168 
169 /*
170  * txt_map_end
171  *	Reset the screen map for colon command-line input.
172  */
173 static int
174 txt_map_end(sp)
175 	SCR *sp;
176 {
177 	VI_PRIVATE *vip;
178 	size_t cnt;
179 
180 	vip = VIP(sp);
181 	if (!IS_ONELINE(sp)) {
182 		/* Restore the screen information. */
183 		sp->t_rows = vip->sv_t_rows;
184 		sp->t_minrows = vip->sv_t_minrows;
185 		sp->t_maxrows = vip->sv_t_maxrows;
186 
187 		/*
188 		 * If it's a small screen, TMAP may be wrong.  Clear any
189 		 * lines that might have been overwritten.
190 		 */
191 		if (IS_SMALL(sp)) {
192 			for (cnt = sp->t_rows; cnt <= sp->t_maxrows; ++cnt) {
193 				(void)sp->gp->scr_move(sp, cnt, 0);
194 				(void)sp->gp->scr_clrtoeol(sp);
195 			}
196 			TMAP = HMAP + (sp->t_rows - 1);
197 		} else
198 			--TMAP;
199 
200 		/*
201 		 * The map may be wrong if the user entered more than one
202 		 * (logical) line.  Fix it.  If the user entered a whole
203 		 * screen, this will be slow, but we probably don't care.
204 		 */
205 		if (!O_ISSET(sp, O_LEFTRIGHT))
206 			while (vip->sv_tm_lno != TMAP->lno ||
207 			    vip->sv_tm_soff != TMAP->soff)
208 				if (vs_sm_1down(sp))
209 					return (1);
210 	}
211 
212 	/*
213 	 * Invalidate the cursor and the line size cache, the line never
214 	 * really existed.  This fixes bugs where the user searches for
215 	 * the last line on the screen + 1 and the refresh routine thinks
216 	 * that's where we just were.
217 	 */
218 	VI_SCR_CFLUSH(vip);
219 	F_SET(vip, VIP_CUR_INVALID);
220 
221 	return (0);
222 }
223 
224 /*
225  * If doing input mapping on the colon command line, may need to unmap
226  * based on the command.
227  */
228 #define	UNMAP_TST							\
229 	FL_ISSET(ec_flags, EC_MAPINPUT) && LF_ISSET(TXT_INFOLINE)
230 
231 /*
232  * Internally, we maintain tp->lno and tp->cno, externally, everyone uses
233  * sp->lno and sp->cno.  Make them consistent as necessary.
234  */
235 #define	UPDATE_POSITION(sp, tp) {					\
236 	(sp)->lno = (tp)->lno;						\
237 	(sp)->cno = (tp)->cno;						\
238 }
239 
240 /*
241  * v_txt --
242  *	Vi text input.
243  *
244  * PUBLIC: int v_txt __P((SCR *, VICMD *, MARK *,
245  * PUBLIC:    const char *, size_t, ARG_CHAR_T, recno_t, u_long, u_int32_t));
246  */
247 int
248 v_txt(sp, vp, tm, lp, len, prompt, ai_line, rcount, flags)
249 	SCR *sp;
250 	VICMD *vp;
251 	MARK *tm;		/* To MARK. */
252 	const char *lp;		/* Input line. */
253 	size_t len;		/* Input line length. */
254 	ARG_CHAR_T prompt;	/* Prompt to display. */
255 	recno_t ai_line;	/* Line number to use for autoindent count. */
256 	u_long rcount;		/* Replay count. */
257 	u_int32_t flags;	/* TXT_* flags. */
258 {
259 	EVENT ev, *evp;		/* Current event. */
260 	EVENT fc;		/* File name completion event. */
261 	GS *gp;
262 	TEXT *ntp, *tp;		/* Input text structures. */
263 	TEXT ait;		/* Autoindent text structure. */
264 	TEXT wmt;		/* Wrapmargin text structure. */
265 	TEXTH *tiqh;
266 	VI_PRIVATE *vip;
267 	abb_t abb;		/* State of abbreviation checks. */
268 	carat_t carat;		/* State of the "[^0]^D" sequences. */
269 	quote_t quote;		/* State of quotation. */
270 	size_t owrite, insert;	/* Temporary copies of TEXT fields. */
271 	size_t margin;		/* Wrapmargin value. */
272 	size_t rcol;		/* 0-N: insert offset in the replay buffer. */
273 	size_t tcol;		/* Temporary column. */
274 	u_int32_t ec_flags;	/* Input mapping flags. */
275 #define	IS_RESTART	0x01	/* Reset the incremental search. */
276 #define	IS_RUNNING	0x02	/* Incremental search turned on. */
277 	u_int8_t is_flags;
278 	int abcnt, ab_turnoff;	/* Abbreviation character count, switch. */
279 	int filec_redraw;	/* Redraw after the file completion routine. */
280 	int hexcnt;		/* Hex character count. */
281 	int showmatch;		/* Showmatch set on this character. */
282 	int wm_set, wm_skip;	/* Wrapmargin happened, blank skip flags. */
283 	int max, tmp;
284 	char *p;
285 
286 	gp = sp->gp;
287 	vip = VIP(sp);
288 
289 	/*
290 	 * Set the input flag, so tabs get displayed correctly
291 	 * and everyone knows that the text buffer is in use.
292 	 */
293 	F_SET(sp, SC_TINPUT);
294 
295 	/*
296 	 * Get one TEXT structure with some initial buffer space, reusing
297 	 * the last one if it's big enough.  (All TEXT bookkeeping fields
298 	 * default to 0 -- text_init() handles this.)  If changing a line,
299 	 * copy it into the TEXT buffer.
300 	 */
301 	tiqh = &sp->tiq;
302 	if (tiqh->cqh_first != (void *)tiqh) {
303 		tp = tiqh->cqh_first;
304 		if (tp->q.cqe_next != (void *)tiqh || tp->lb_len < len + 32) {
305 			text_lfree(tiqh);
306 			goto newtp;
307 		}
308 		tp->ai = tp->insert = tp->offset = tp->owrite = 0;
309 		if (lp != NULL) {
310 			tp->len = len;
311 			memmove(tp->lb, lp, len);
312 		} else
313 			tp->len = 0;
314 	} else {
315 newtp:		if ((tp = text_init(sp, lp, len, len + 32)) == NULL)
316 			return (1);
317 		CIRCLEQ_INSERT_HEAD(tiqh, tp, q);
318 	}
319 
320 	/* Set default termination condition. */
321 	tp->term = TERM_OK;
322 
323 	/* Set the starting line, column. */
324 	tp->lno = sp->lno;
325 	tp->cno = sp->cno;
326 
327 	/*
328 	 * Set the insert and overwrite counts.  If overwriting characters,
329 	 * do insertion afterward.  If not overwriting characters, assume
330 	 * doing insertion.  If change is to a mark, emphasize it with an
331 	 * CH_ENDMARK character.
332 	 */
333 	if (len) {
334 		if (LF_ISSET(TXT_OVERWRITE)) {
335 			tp->owrite = (tm->cno - tp->cno) + 1;
336 			tp->insert = (len - tm->cno) - 1;
337 		} else
338 			tp->insert = len - tp->cno;
339 
340 		if (LF_ISSET(TXT_EMARK) && txt_emark(sp, tp, tm->cno))
341 			return (1);
342 	}
343 
344 	/*
345 	 * Many of the special cases in text input are to handle autoindent
346 	 * support.  Somebody decided that it would be a good idea if "^^D"
347 	 * and "0^D" deleted all of the autoindented characters.  In an editor
348 	 * that takes single character input from the user, this beggars the
349 	 * imagination.  Note also, "^^D" resets the next lines' autoindent,
350 	 * but "0^D" doesn't.
351 	 *
352 	 * We assume that autoindent only happens on empty lines, so insert
353 	 * and overwrite will be zero.  If doing autoindent, figure out how
354 	 * much indentation we need and fill it in.  Update input column and
355 	 * screen cursor as necessary.
356 	 */
357 	if (LF_ISSET(TXT_AUTOINDENT) && ai_line != OOBLNO) {
358 		if (v_txt_auto(sp, ai_line, NULL, 0, tp))
359 			return (1);
360 		tp->cno = tp->ai;
361 	} else {
362 		/*
363 		 * The cc and S commands have a special feature -- leading
364 		 * <blank> characters are handled as autoindent characters.
365 		 * Beauty!
366 		 */
367 		if (LF_ISSET(TXT_AICHARS)) {
368 			tp->offset = 0;
369 			tp->ai = tp->cno;
370 		} else
371 			tp->offset = tp->cno;
372 	}
373 
374 	/* If getting a command buffer from the user, there may be a prompt. */
375 	if (LF_ISSET(TXT_PROMPT)) {
376 		tp->lb[tp->cno++] = prompt;
377 		++tp->len;
378 		++tp->offset;
379 	}
380 
381 	/*
382 	 * If appending after the end-of-line, add a space into the buffer
383 	 * and move the cursor right.  This space is inserted, i.e. pushed
384 	 * along, and then deleted when the line is resolved.  Assumes that
385 	 * the cursor is already positioned at the end of the line.  This
386 	 * avoids the nastiness of having the cursor reside on a magical
387 	 * column, i.e. a column that doesn't really exist.  The only down
388 	 * side is that we may wrap lines or scroll the screen before it's
389 	 * strictly necessary.  Not a big deal.
390 	 */
391 	if (LF_ISSET(TXT_APPENDEOL)) {
392 		tp->lb[tp->cno] = CH_CURSOR;
393 		++tp->len;
394 		++tp->insert;
395 		(void)vs_change(sp, tp->lno, LINE_RESET);
396 	}
397 
398 	/*
399 	 * Historic practice is that the wrapmargin value was a distance
400 	 * from the RIGHT-HAND margin, not the left.  It's more useful to
401 	 * us as a distance from the left-hand margin, i.e. the same as
402 	 * the wraplen value.  The wrapmargin option is historic practice.
403 	 * Nvi added the wraplen option so that it would be possible to
404 	 * edit files with consistent margins without knowing the number of
405 	 * columns in the window.
406 	 *
407 	 * XXX
408 	 * Setting margin causes a significant performance hit.  Normally
409 	 * we don't update the screen if there are keys waiting, but we
410 	 * have to if margin is set, otherwise the screen routines don't
411 	 * know where the cursor is.
412 	 *
413 	 * !!!
414 	 * Abbreviated keys were affected by the wrapmargin option in the
415 	 * historic 4BSD vi.  Mapped keys were usually, but sometimes not.
416 	 * See the comment in vi/v_text():set_txt_std for more information.
417 	 *
418 	 * !!!
419 	 * One more special case.  If an inserted <blank> character causes
420 	 * wrapmargin to split the line, the next user entered character is
421 	 * discarded if it's a <space> character.
422 	 */
423 	wm_set = wm_skip = 0;
424 	if (LF_ISSET(TXT_WRAPMARGIN))
425 		if ((margin = O_VAL(sp, O_WRAPMARGIN)) != 0)
426 			margin = sp->cols - margin;
427 		else
428 			margin = O_VAL(sp, O_WRAPLEN);
429 	else
430 		margin = 0;
431 
432 	/* Initialize abbreviation checks. */
433 	abcnt = ab_turnoff = 0;
434 	abb = F_ISSET(gp, G_ABBREV) &&
435 	    LF_ISSET(TXT_MAPINPUT) ? AB_INWORD : AB_NOTSET;
436 
437 	/*
438 	 * Set up the dot command.  Dot commands are done by saving the actual
439 	 * characters and then reevaluating them so that things like wrapmargin
440 	 * can change between the insert and the replay.
441 	 *
442 	 * !!!
443 	 * Historically, vi did not remap or reabbreviate replayed input.  (It
444 	 * did beep at you if you changed an abbreviation and then replayed the
445 	 * input.  We're not that compatible.)  We don't have to do anything to
446 	 * avoid remapping, as we're not getting characters from the terminal
447 	 * routines.  Turn the abbreviation check off.
448 	 *
449 	 * XXX
450 	 * It would be nice if we could swallow backspaces and such, but it's
451 	 * not all that easy to do.  What we can do is turn off the common
452 	 * error messages during the replay.  Otherwise, when the user enters
453 	 * an illegal command, e.g., "Ia<erase><erase><erase><erase>b<escape>",
454 	 * and then does a '.', they get a list of error messages after command
455 	 * completion.
456 	 */
457 	rcol = 0;
458 	if (LF_ISSET(TXT_REPLAY)) {
459 		abb = AB_NOTSET;
460 		LF_CLR(TXT_RECORD);
461 	}
462 
463 	/* Other text input mode setup. */
464 	quote = Q_NOTSET;
465 	carat = C_NOTSET;
466 	FL_INIT(is_flags,
467 	    LF_ISSET(TXT_SEARCHINCR) ? IS_RESTART | IS_RUNNING : 0);
468 	filec_redraw = hexcnt = showmatch = 0;
469 
470 	/* Initialize input flags. */
471 	ec_flags = LF_ISSET(TXT_MAPINPUT) ? EC_MAPINPUT : 0;
472 
473 	/* Refresh the screen. */
474 	UPDATE_POSITION(sp, tp);
475 	if (vs_refresh(sp, 1))
476 		return (1);
477 
478 	/* If it's dot, just do it now. */
479 	if (F_ISSET(vp, VC_ISDOT))
480 		goto replay;
481 
482 	/* Get an event. */
483 	evp = &ev;
484 next:	if (v_event_get(sp, evp, 0, ec_flags))
485 		return (1);
486 
487 	/*
488 	 * If file completion overwrote part of the screen and nothing else has
489 	 * been displayed, clean up.  We don't do this as part of the normal
490 	 * message resolution because we know the user is on the colon command
491 	 * line and there's no reason to enter explicit characters to continue.
492 	 */
493 	if (filec_redraw && !F_ISSET(sp, SC_SCR_EXWROTE)) {
494 		filec_redraw = 0;
495 
496 		fc.e_event = E_REPAINT;
497 		fc.e_flno = vip->totalcount >=
498 		    sp->rows ? 1 : sp->rows - vip->totalcount;
499 		fc.e_tlno = sp->rows;
500 		vip->linecount = vip->lcontinue = vip->totalcount = 0;
501 		(void)vs_repaint(sp, &fc);
502 		(void)vs_refresh(sp, 1);
503 	}
504 
505 	/* Deal with all non-character events. */
506 	switch (evp->e_event) {
507 	case E_CHARACTER:
508 		break;
509 	case E_ERR:
510 	case E_EOF:
511 		F_SET(sp, SC_EXIT_FORCE);
512 		return (1);
513 	case E_INTERRUPT:
514 		/*
515 		 * !!!
516 		 * Historically, <interrupt> exited the user from text input
517 		 * mode or cancelled a colon command, and returned to command
518 		 * mode.  It also beeped the terminal, but that seems a bit
519 		 * excessive.
520 		 */
521 		goto k_escape;
522 	case E_REPAINT:
523 		if (vs_repaint(sp, &ev))
524 			return (1);
525 		goto next;
526 	case E_WRESIZE:
527 		/* <resize> interrupts the input mode. */
528 		v_emsg(sp, NULL, VIM_WRESIZE);
529 		goto k_escape;
530 	default:
531 		v_event_err(sp, evp);
532 		goto k_escape;
533 	}
534 
535 	/*
536 	 * !!!
537 	 * If the first character of the input is a nul, replay the previous
538 	 * input.  (Historically, it's okay to replay non-existent input.)
539 	 * This was not documented as far as I know, and is a great test of vi
540 	 * clones.
541 	 */
542 	if (rcol == 0 && !LF_ISSET(TXT_REPLAY) && evp->e_c == '\0') {
543 		if (vip->rep == NULL)
544 			goto done;
545 
546 		abb = AB_NOTSET;
547 		LF_CLR(TXT_RECORD);
548 		LF_SET(TXT_REPLAY);
549 		goto replay;
550 	}
551 
552 	/*
553 	 * File name completion and colon command-line editing.   We don't
554 	 * have enough meta characters, so we expect people to overload
555 	 * them.  If the two characters are the same, then we do file name
556 	 * completion if the cursor is past the first column, and do colon
557 	 * command-line editing if it's not.
558 	 */
559 	if (quote == Q_NOTSET) {
560 		int L__cedit, L__filec;
561 
562 		L__cedit = L__filec = 0;
563 		if (LF_ISSET(TXT_CEDIT) && O_STR(sp, O_CEDIT) != NULL &&
564 		    O_STR(sp, O_CEDIT)[0] == evp->e_c)
565 			L__cedit = 1;
566 		if (LF_ISSET(TXT_FILEC) && O_STR(sp, O_FILEC) != NULL &&
567 		    O_STR(sp, O_FILEC)[0] == evp->e_c)
568 			L__filec = 1;
569 		if (L__cedit == 1 && (L__filec == 0 || tp->cno == tp->offset)) {
570 			tp->term = TERM_CEDIT;
571 			goto k_escape;
572 		}
573 		if (L__filec == 1) {
574 			if (txt_fc(sp, tp, &filec_redraw))
575 				goto err;
576 			goto resolve;
577 		}
578 	}
579 
580 	/* Abbreviation overflow check.  See comment in txt_abbrev(). */
581 #define	MAX_ABBREVIATION_EXPANSION	256
582 	if (F_ISSET(&evp->e_ch, CH_ABBREVIATED)) {
583 		if (++abcnt > MAX_ABBREVIATION_EXPANSION) {
584 			if (v_event_flush(sp, CH_ABBREVIATED))
585 				msgq(sp, M_ERR,
586 "191|Abbreviation exceeded expansion limit: characters discarded");
587 			abcnt = 0;
588 			if (LF_ISSET(TXT_REPLAY))
589 				goto done;
590 			goto resolve;
591 		}
592 	} else
593 		abcnt = 0;
594 
595 	/* Check to see if the character fits into the replay buffers. */
596 	if (LF_ISSET(TXT_RECORD)) {
597 		BINC_GOTO(sp, vip->rep,
598 		    vip->rep_len, (rcol + 1) * sizeof(EVENT));
599 		vip->rep[rcol++] = *evp;
600 	}
601 
602 replay:	if (LF_ISSET(TXT_REPLAY))
603 		evp = vip->rep + rcol++;
604 
605 	/* Wrapmargin check for leading space. */
606 	if (wm_skip) {
607 		wm_skip = 0;
608 		if (evp->e_c == ' ')
609 			goto resolve;
610 	}
611 
612 	/* If quoted by someone else, simply insert the character. */
613 	if (F_ISSET(&evp->e_ch, CH_QUOTED))
614 		goto insq_ch;
615 
616 	/*
617 	 * !!!
618 	 * If this character was quoted by a K_VLNEXT or a backslash, replace
619 	 * the placeholder (a carat or a backslash) with the new character.
620 	 * If it was quoted by a K_VLNEXT, we've already adjusted the cursor
621 	 * because it has to appear on top of the placeholder character.  If
622 	 * it was quoted by a backslash, adjust the cursor now, the cursor
623 	 * doesn't appear on top of it.  Historic practice in both cases.
624 	 *
625 	 * Skip tests for abbreviations; ":ab xa XA" followed by "ixa^V<space>"
626 	 * doesn't perform an abbreviation.  Special case, ^V^J (not ^V^M) is
627 	 * the same as ^J, historically.
628 	 */
629 	if (quote == Q_BTHIS || quote == Q_VTHIS) {
630 		FL_CLR(ec_flags, EC_QUOTED);
631 		if (LF_ISSET(TXT_MAPINPUT))
632 			FL_SET(ec_flags, EC_MAPINPUT);
633 
634 		if (quote == Q_BTHIS &&
635 		    (evp->e_value == K_VERASE || evp->e_value == K_VKILL)) {
636 			quote = Q_NOTSET;
637 			--tp->cno;
638 			++tp->owrite;
639 			goto insl_ch;
640 		}
641 		if (quote == Q_VTHIS && evp->e_value != K_NL) {
642 			quote = Q_NOTSET;
643 			goto insl_ch;
644 		}
645 		quote = Q_NOTSET;
646 	}
647 
648 	/*
649 	 * !!!
650 	 * Translate "<CH_HEX>[isxdigit()]*" to a character with a hex value:
651 	 * this test delimits the value by any non-hex character.  Offset by
652 	 * one, we use 0 to mean that we've found <CH_HEX>.
653 	 */
654 	if (hexcnt > 1 && !isxdigit(evp->e_c)) {
655 		hexcnt = 0;
656 		if (txt_hex(sp, tp))
657 			goto err;
658 	}
659 
660 	switch (evp->e_value) {
661 	case K_CR:				/* Carriage return. */
662 	case K_NL:				/* New line. */
663 		/* Return in script windows and the command line. */
664 k_cr:		if (LF_ISSET(TXT_CR)) {
665 			/*
666 			 * If this was a map, we may have not displayed
667 			 * the line.  Display it, just in case.
668 			 *
669 			 * If a script window and not the colon line,
670 			 * push a <cr> so it gets executed.
671 			 */
672 			if (LF_ISSET(TXT_INFOLINE)) {
673 				if (vs_change(sp, tp->lno, LINE_RESET))
674 					goto err;
675 			} else if (F_ISSET(sp, SC_SCRIPT))
676 				(void)v_event_push(sp, NULL, "\r", 1, CH_NOMAP);
677 
678 			/* Set term condition: if empty. */
679 			if (tp->cno <= tp->offset)
680 				tp->term = TERM_CR;
681 			/*
682 			 * Set term condition: if searching incrementally and
683 			 * the user entered a pattern, return a completed
684 			 * search, regardless if the entire pattern was found.
685 			 */
686 			if (FL_ISSET(is_flags, IS_RUNNING) &&
687 			    tp->cno >= tp->offset + 1)
688 				tp->term = TERM_SEARCH;
689 
690 			goto k_escape;
691 		}
692 
693 #define	LINE_RESOLVE {							\
694 		/*							\
695 		 * Handle abbreviations.  If there was one, discard the	\
696 		 * replay characters.					\
697 		 */							\
698 		if (abb == AB_INWORD &&					\
699 		    !LF_ISSET(TXT_REPLAY) && F_ISSET(gp, G_ABBREV)) {	\
700 			if (txt_abbrev(sp, tp, &evp->e_c,		\
701 			    LF_ISSET(TXT_INFOLINE), &tmp,		\
702 			    &ab_turnoff))				\
703 				goto err;				\
704 			if (tmp) {					\
705 				if (LF_ISSET(TXT_RECORD))		\
706 					rcol -= tmp + 1;		\
707 				goto resolve;				\
708 			}						\
709 		}							\
710 		if (abb != AB_NOTSET)					\
711 			abb = AB_NOTWORD;				\
712 		if (UNMAP_TST)						\
713 			txt_unmap(sp, tp, &ec_flags);			\
714 		/*							\
715 		 * Delete any appended cursor.  It's possible to get in	\
716 		 * situations where TXT_APPENDEOL is set but tp->insert	\
717 		 * is 0 when using the R command and all the characters	\
718 		 * are tp->owrite characters.				\
719 		 */							\
720 		if (LF_ISSET(TXT_APPENDEOL) && tp->insert > 0) {	\
721 			--tp->len;					\
722 			--tp->insert;					\
723 		}							\
724 }
725 		LINE_RESOLVE;
726 
727 		/*
728 		 * Save the current line information for restoration in
729 		 * txt_backup(), and set the line final length.
730 		 */
731 		tp->sv_len = tp->len;
732 		tp->sv_cno = tp->cno;
733 		tp->len = tp->cno;
734 
735 		/* Update the old line. */
736 		if (vs_change(sp, tp->lno, LINE_RESET))
737 			goto err;
738 
739 		/*
740 		 * Historic practice, when the autoindent edit option was set,
741 		 * was to delete <blank> characters following the inserted
742 		 * newline.  This affected the 'R', 'c', and 's' commands; 'c'
743 		 * and 's' retained the insert characters only, 'R' moved the
744 		 * overwrite and insert characters into the next TEXT structure.
745 		 * We keep track of the number of characters erased for the 'R'
746 		 * command so that the final resolution of the line is correct.
747 		 */
748 		tp->R_erase = 0;
749 		owrite = tp->owrite;
750 		insert = tp->insert;
751 		if (LF_ISSET(TXT_REPLACE) && owrite != 0) {
752 			for (p = tp->lb + tp->cno; owrite > 0 && isblank(*p);
753 			    ++p, --owrite, ++tp->R_erase);
754 			if (owrite == 0)
755 				for (; insert > 0 && isblank(*p);
756 				    ++p, ++tp->R_erase, --insert);
757 		} else {
758 			p = tp->lb + tp->cno + owrite;
759 			if (O_ISSET(sp, O_AUTOINDENT))
760 				for (; insert > 0 &&
761 				    isblank(*p); ++p, --insert);
762 			owrite = 0;
763 		}
764 
765 		/*
766 		 * !!!
767 		 * Create a new line and insert the new TEXT into the queue.
768 		 * DON'T insert until the old line has been updated, or the
769 		 * inserted line count in line.c:db_get() will be wrong.
770 		 */
771 		if ((ntp = text_init(sp, p,
772 		    insert + owrite, insert + owrite + 32)) == NULL)
773 			goto err;
774 		CIRCLEQ_INSERT_TAIL(&sp->tiq, ntp, q);
775 
776 		/* Set up bookkeeping for the new line. */
777 		ntp->insert = insert;
778 		ntp->owrite = owrite;
779 		ntp->lno = tp->lno + 1;
780 
781 		/*
782 		 * Reset the autoindent line value.  0^D keeps the autoindent
783 		 * line from changing, ^D changes the level, even if there were
784 		 * no characters in the old line.  Note, if using the current
785 		 * tp structure, use the cursor as the length, the autoindent
786 		 * characters may have been erased.
787 		 */
788 		if (LF_ISSET(TXT_AUTOINDENT)) {
789 			if (carat == C_NOCHANGE) {
790 				if (v_txt_auto(sp, OOBLNO, &ait, ait.ai, ntp))
791 					goto err;
792 				FREE_SPACE(sp, ait.lb, ait.lb_len);
793 			} else
794 				if (v_txt_auto(sp, OOBLNO, tp, tp->cno, ntp))
795 					goto err;
796 			carat = C_NOTSET;
797 		}
798 
799 		/* Reset the cursor. */
800 		ntp->cno = ntp->ai;
801 
802 		/*
803 		 * If we're here because wrapmargin was set and we've broken a
804 		 * line, there may be additional information (i.e. the start of
805 		 * a line) in the wmt structure.
806 		 */
807 		if (wm_set) {
808 			if (wmt.offset != 0 ||
809 			    wmt.owrite != 0 || wmt.insert != 0) {
810 #define	WMTSPACE	wmt.offset + wmt.owrite + wmt.insert
811 				BINC_GOTO(sp, ntp->lb,
812 				    ntp->lb_len, ntp->len + WMTSPACE + 32);
813 				memmove(ntp->lb + ntp->cno, wmt.lb, WMTSPACE);
814 				ntp->len += WMTSPACE;
815 				ntp->cno += wmt.offset;
816 				ntp->owrite = wmt.owrite;
817 				ntp->insert = wmt.insert;
818 			}
819 			wm_set = 0;
820 		}
821 
822 		/* New lines are TXT_APPENDEOL. */
823 		if (ntp->owrite == 0 && ntp->insert == 0) {
824 			BINC_GOTO(sp, ntp->lb, ntp->lb_len, ntp->len + 1);
825 			LF_SET(TXT_APPENDEOL);
826 			ntp->lb[ntp->cno] = CH_CURSOR;
827 			++ntp->insert;
828 			++ntp->len;
829 		}
830 
831 		/* Swap old and new TEXT's, and update the new line. */
832 		tp = ntp;
833 		if (vs_change(sp, tp->lno, LINE_INSERT))
834 			goto err;
835 
836 		goto resolve;
837 	case K_ESCAPE:				/* Escape. */
838 		if (!LF_ISSET(TXT_ESCAPE))
839 			goto ins_ch;
840 
841 		/* If we have a count, start replaying the input. */
842 		if (rcount > 1) {
843 			--rcount;
844 
845 			rcol = 0;
846 			abb = AB_NOTSET;
847 			LF_CLR(TXT_RECORD);
848 			LF_SET(TXT_REPLAY);
849 
850 			/*
851 			 * Some commands (e.g. 'o') need a <newline> for each
852 			 * repetition.
853 			 */
854 			if (LF_ISSET(TXT_ADDNEWLINE))
855 				goto k_cr;
856 
857 			/*
858 			 * The R command turns into the 'a' command after the
859 			 * first repetition.
860 			 */
861 			if (LF_ISSET(TXT_REPLACE)) {
862 				tp->insert = tp->owrite;
863 				tp->owrite = 0;
864 				LF_CLR(TXT_REPLACE);
865 			}
866 			goto replay;
867 		}
868 
869 		/* Set term condition: if empty. */
870 		if (tp->cno <= tp->offset)
871 			tp->term = TERM_ESC;
872 		/*
873 		 * Set term condition: if searching incrementally and the user
874 		 * entered a pattern, return a completed search, regardless if
875 		 * the entire pattern was found.
876 		 */
877 		if (FL_ISSET(is_flags, IS_RUNNING) && tp->cno >= tp->offset + 1)
878 			tp->term = TERM_SEARCH;
879 
880 k_escape:	LINE_RESOLVE;
881 
882 		/*
883 		 * Clean up for the 'R' command, restoring overwrite
884 		 * characters, and making them into insert characters.
885 		 */
886 		if (LF_ISSET(TXT_REPLACE))
887 			txt_Rresolve(sp, &sp->tiq, tp, len);
888 
889 		/*
890 		 * If there are any overwrite characters, copy down
891 		 * any insert characters, and decrement the length.
892 		 */
893 		if (tp->owrite) {
894 			if (tp->insert)
895 				memmove(tp->lb + tp->cno,
896 				    tp->lb + tp->cno + tp->owrite, tp->insert);
897 			tp->len -= tp->owrite;
898 		}
899 
900 		/*
901 		 * Optionally resolve the lines into the file.  If not
902 		 * resolving the lines into the file, end the line with
903 		 * a nul.  If the line is empty, then set the length to
904 		 * 0, the termination condition has already been set.
905 		 *
906 		 * XXX
907 		 * This is wrong, should pass back a length.
908 		 */
909 		if (LF_ISSET(TXT_RESOLVE)) {
910 			if (txt_resolve(sp, &sp->tiq, flags))
911 				goto err;
912 		} else {
913 			BINC_GOTO(sp, tp->lb, tp->lb_len, tp->len + 1);
914 			tp->lb[tp->len] = '\0';
915 		}
916 
917 		/*
918 		 * Set the return cursor position to rest on the last
919 		 * inserted character.
920 		 */
921 		if (tp->cno != 0)
922 			--tp->cno;
923 
924 		/* Update the last line. */
925 		if (vs_change(sp, tp->lno, LINE_RESET))
926 			return (1);
927 		goto done;
928 	case K_CARAT:			/* Delete autoindent chars. */
929 		if (tp->cno <= tp->ai && LF_ISSET(TXT_AUTOINDENT))
930 			carat = C_CARATSET;
931 		goto ins_ch;
932 	case K_ZERO:			/* Delete autoindent chars. */
933 		if (tp->cno <= tp->ai && LF_ISSET(TXT_AUTOINDENT))
934 			carat = C_ZEROSET;
935 		goto ins_ch;
936 	case K_CNTRLD:			/* Delete autoindent char. */
937 		/*
938 		 * If in the first column or no characters to erase, ignore
939 		 * the ^D (this matches historic practice).  If not doing
940 		 * autoindent or already inserted non-ai characters, it's a
941 		 * literal.  The latter test is done in the switch, as the
942 		 * CARAT forms are N + 1, not N.
943 		 */
944 		if (!LF_ISSET(TXT_AUTOINDENT))
945 			goto ins_ch;
946 		if (tp->cno == 0)
947 			goto resolve;
948 
949 		switch (carat) {
950 		case C_CARATSET:	/* ^^D */
951 			if (tp->ai == 0 || tp->cno > tp->ai + tp->offset + 1)
952 				goto ins_ch;
953 
954 			/* Save the ai string for later. */
955 			ait.lb = NULL;
956 			ait.lb_len = 0;
957 			BINC_GOTO(sp, ait.lb, ait.lb_len, tp->ai);
958 			memmove(ait.lb, tp->lb, tp->ai);
959 			ait.ai = ait.len = tp->ai;
960 
961 			carat = C_NOCHANGE;
962 			goto leftmargin;
963 		case C_ZEROSET:		/* 0^D */
964 			if (tp->ai == 0 || tp->cno > tp->ai + tp->offset + 1)
965 				goto ins_ch;
966 
967 			carat = C_NOTSET;
968 leftmargin:		tp->lb[tp->cno - 1] = ' ';
969 			tp->owrite += tp->cno - tp->offset;
970 			tp->ai = 0;
971 			tp->cno = tp->offset;
972 			break;
973 		case C_NOTSET:		/* ^D */
974 			if (tp->ai == 0 || tp->cno > tp->ai + tp->offset)
975 				goto ins_ch;
976 
977 			(void)txt_dent(sp, tp, 0);
978 			break;
979 		default:
980 			abort();
981 		}
982 		break;
983 	case K_VERASE:			/* Erase the last character. */
984 		/* If can erase over the prompt, return. */
985 		if (tp->cno <= tp->offset && LF_ISSET(TXT_BS)) {
986 			tp->term = TERM_BS;
987 			goto done;
988 		}
989 
990 		/*
991 		 * If at the beginning of the line, try and drop back to a
992 		 * previously inserted line.
993 		 */
994 		if (tp->cno == 0) {
995 			if ((ntp =
996 			    txt_backup(sp, &sp->tiq, tp, &flags)) == NULL)
997 				goto err;
998 			tp = ntp;
999 			break;
1000 		}
1001 
1002 		/* If nothing to erase, bell the user. */
1003 		if (tp->cno <= tp->offset) {
1004 			if (!LF_ISSET(TXT_REPLAY))
1005 				txt_nomorech(sp);
1006 			break;
1007 		}
1008 
1009 		/* Drop back one character. */
1010 		--tp->cno;
1011 
1012 		/*
1013 		 * Historically, vi didn't replace the erased characters with
1014 		 * <blank>s, presumably because it's easier to fix a minor
1015 		 * typing mistake and continue on if the previous letters are
1016 		 * already there.  This is a problem for incremental searching,
1017 		 * because the user can no longer tell where they are in the
1018 		 * colon command line because the cursor is at the last search
1019 		 * point in the screen.  So, if incrementally searching, erase
1020 		 * the erased characters from the screen.
1021 		 */
1022 		if (FL_ISSET(is_flags, IS_RUNNING))
1023 			tp->lb[tp->cno] = ' ';
1024 
1025 		/*
1026 		 * Increment overwrite, decrement ai if deleted.
1027 		 *
1028 		 * !!!
1029 		 * Historic vi did not permit users to use erase characters
1030 		 * to delete autoindent characters.  We do.  Eat hot death,
1031 		 * POSIX.
1032 		 */
1033 		++tp->owrite;
1034 		if (tp->cno < tp->ai)
1035 			--tp->ai;
1036 
1037 		/* Reset if we deleted an incremental search character. */
1038 		if (FL_ISSET(is_flags, IS_RUNNING))
1039 			FL_SET(is_flags, IS_RESTART);
1040 		break;
1041 	case K_VWERASE:			/* Skip back one word. */
1042 		/*
1043 		 * If at the beginning of the line, try and drop back to a
1044 		 * previously inserted line.
1045 		 */
1046 		if (tp->cno == 0) {
1047 			if ((ntp =
1048 			    txt_backup(sp, &sp->tiq, tp, &flags)) == NULL)
1049 				goto err;
1050 			tp = ntp;
1051 		}
1052 
1053 		/*
1054 		 * If at offset, nothing to erase so bell the user.
1055 		 */
1056 		if (tp->cno <= tp->offset) {
1057 			if (!LF_ISSET(TXT_REPLAY))
1058 				txt_nomorech(sp);
1059 			break;
1060 		}
1061 
1062 		/*
1063 		 * The first werase goes back to any autoindent column and the
1064 		 * second werase goes back to the offset.
1065 		 *
1066 		 * !!!
1067 		 * Historic vi did not permit users to use erase characters to
1068 		 * delete autoindent characters.
1069 		 */
1070 		if (tp->ai && tp->cno > tp->ai)
1071 			max = tp->ai;
1072 		else {
1073 			tp->ai = 0;
1074 			max = tp->offset;
1075 		}
1076 
1077 		/* Skip over trailing space characters. */
1078 		while (tp->cno > max && isblank(tp->lb[tp->cno - 1])) {
1079 			--tp->cno;
1080 			++tp->owrite;
1081 		}
1082 		if (tp->cno == max)
1083 			break;
1084 		/*
1085 		 * There are three types of word erase found on UNIX systems.
1086 		 * They can be identified by how the string /a/b/c is treated
1087 		 * -- as 1, 3, or 6 words.  Historic vi had two classes of
1088 		 * characters, and strings were delimited by them and
1089 		 * <blank>'s, so, 6 words.  The historic tty interface used
1090 		 * <blank>'s to delimit strings, so, 1 word.  The algorithm
1091 		 * offered in the 4.4BSD tty interface (as stty altwerase)
1092 		 * treats it as 3 words -- there are two classes of
1093 		 * characters, and strings are delimited by them and
1094 		 * <blank>'s.  The difference is that the type of the first
1095 		 * erased character erased is ignored, which is exactly right
1096 		 * when erasing pathname components.  The edit options
1097 		 * TXT_ALTWERASE and TXT_TTYWERASE specify the 4.4BSD tty
1098 		 * interface and the historic tty driver behavior,
1099 		 * respectively, and the default is the same as the historic
1100 		 * vi behavior.
1101 		 *
1102 		 * Overwrite erased characters if doing incremental search;
1103 		 * see comment above.
1104 		 */
1105 		if (LF_ISSET(TXT_TTYWERASE))
1106 			while (tp->cno > max) {
1107 				--tp->cno;
1108 				++tp->owrite;
1109 				if (FL_ISSET(is_flags, IS_RUNNING))
1110 					tp->lb[tp->cno] = ' ';
1111 				if (isblank(tp->lb[tp->cno - 1]))
1112 					break;
1113 			}
1114 		else {
1115 			if (LF_ISSET(TXT_ALTWERASE)) {
1116 				--tp->cno;
1117 				++tp->owrite;
1118 				if (FL_ISSET(is_flags, IS_RUNNING))
1119 					tp->lb[tp->cno] = ' ';
1120 				if (isblank(tp->lb[tp->cno - 1]))
1121 					break;
1122 			}
1123 			if (tp->cno > max)
1124 				tmp = inword(tp->lb[tp->cno - 1]);
1125 			while (tp->cno > max) {
1126 				--tp->cno;
1127 				++tp->owrite;
1128 				if (FL_ISSET(is_flags, IS_RUNNING))
1129 					tp->lb[tp->cno] = ' ';
1130 				if (tmp != inword(tp->lb[tp->cno - 1])
1131 				    || isblank(tp->lb[tp->cno - 1]))
1132 					break;
1133 			}
1134 		}
1135 
1136 		/* Reset if we deleted an incremental search character. */
1137 		if (FL_ISSET(is_flags, IS_RUNNING))
1138 			FL_SET(is_flags, IS_RESTART);
1139 		break;
1140 	case K_VKILL:			/* Restart this line. */
1141 		/*
1142 		 * !!!
1143 		 * If at the beginning of the line, try and drop back to a
1144 		 * previously inserted line.  Historic vi did not permit
1145 		 * users to go back to previous lines.
1146 		 */
1147 		if (tp->cno == 0) {
1148 			if ((ntp =
1149 			    txt_backup(sp, &sp->tiq, tp, &flags)) == NULL)
1150 				goto err;
1151 			tp = ntp;
1152 		}
1153 
1154 		/* If at offset, nothing to erase so bell the user. */
1155 		if (tp->cno <= tp->offset) {
1156 			if (!LF_ISSET(TXT_REPLAY))
1157 				txt_nomorech(sp);
1158 			break;
1159 		}
1160 
1161 		/*
1162 		 * First kill goes back to any autoindent and second kill goes
1163 		 * back to the offset.
1164 		 *
1165 		 * !!!
1166 		 * Historic vi did not permit users to use erase characters to
1167 		 * delete autoindent characters.
1168 		 */
1169 		if (tp->ai && tp->cno > tp->ai)
1170 			max = tp->ai;
1171 		else {
1172 			tp->ai = 0;
1173 			max = tp->offset;
1174 		}
1175 		tp->owrite += tp->cno - max;
1176 
1177 		/*
1178 		 * Overwrite erased characters if doing incremental search;
1179 		 * see comment above.
1180 		 */
1181 		if (FL_ISSET(is_flags, IS_RUNNING))
1182 			do {
1183 				tp->lb[--tp->cno] = ' ';
1184 			} while (tp->cno > max);
1185 		else
1186 			tp->cno = max;
1187 
1188 		/* Reset if we deleted an incremental search character. */
1189 		if (FL_ISSET(is_flags, IS_RUNNING))
1190 			FL_SET(is_flags, IS_RESTART);
1191 		break;
1192 	case K_CNTRLT:			/* Add autoindent characters. */
1193 		if (!LF_ISSET(TXT_CNTRLT))
1194 			goto ins_ch;
1195 		if (txt_dent(sp, tp, 1))
1196 			goto err;
1197 		goto ebuf_chk;
1198 	case K_RIGHTBRACE:
1199 	case K_RIGHTPAREN:
1200 		if (LF_ISSET(TXT_SHOWMATCH))
1201 			showmatch = 1;
1202 		goto ins_ch;
1203 	case K_BACKSLASH:		/* Quote next erase/kill. */
1204 		/*
1205 		 * !!!
1206 		 * Historic vi tried to make abbreviations after a backslash
1207 		 * escape work.  If you did ":ab x y", and inserted "x\^H",
1208 		 * (assuming the erase character was ^H) you got "x^H", and
1209 		 * no abbreviation was done.  If you inserted "x\z", however,
1210 		 * it tried to back up and do the abbreviation, i.e. replace
1211 		 * 'x' with 'y'.  The problem was it got it wrong, and you
1212 		 * ended up with "zy\".
1213 		 *
1214 		 * This is really hard to do (you have to remember the
1215 		 * word/non-word state, for example), and doesn't make any
1216 		 * sense to me.  Both backslash and the characters it
1217 		 * (usually) escapes will individually trigger the
1218 		 * abbreviation, so I don't see why the combination of them
1219 		 * wouldn't.  I don't expect to get caught on this one,
1220 		 * particularly since it never worked right, but I've been
1221 		 * wrong before.
1222 		 *
1223 		 * Do the tests for abbreviations, so ":ab xa XA",
1224 		 * "ixa\<K_VERASE>" performs the abbreviation.
1225 		 */
1226 		quote = Q_BNEXT;
1227 		goto insq_ch;
1228 	case K_VLNEXT:			/* Quote next character. */
1229 		evp->e_c = '^';
1230 		quote = Q_VNEXT;
1231 		/*
1232 		 * Turn on the quote flag so that the underlying routines
1233 		 * quote the next character where it's possible. Turn off
1234 		 * the input mapbiting flag so that we don't remap the next
1235 		 * character.
1236 		 */
1237 		FL_SET(ec_flags, EC_QUOTED);
1238 		FL_CLR(ec_flags, EC_MAPINPUT);
1239 
1240 		/*
1241 		 * !!!
1242 		 * Skip the tests for abbreviations, so ":ab xa XA",
1243 		 * "ixa^V<space>" doesn't perform the abbreviation.
1244 		 */
1245 		goto insl_ch;
1246 	case K_HEXCHAR:
1247 		hexcnt = 1;
1248 		goto insq_ch;
1249 	default:			/* Insert the character. */
1250 ins_ch:		/*
1251 		 * Historically, vi eliminated nul's out of hand.  If the
1252 		 * beautify option was set, it also deleted any unknown
1253 		 * ASCII value less than space (040) and the del character
1254 		 * (0177), except for tabs.  Unknown is a key word here.
1255 		 * Most vi documentation claims that it deleted everything
1256 		 * but <tab>, <nl> and <ff>, as that's what the original
1257 		 * 4BSD documentation said.  This is obviously wrong,
1258 		 * however, as <esc> would be included in that list.  What
1259 		 * we do is eliminate any unquoted, iscntrl() character that
1260 		 * wasn't a replay and wasn't handled specially, except
1261 		 * <tab> or <ff>.
1262 		 */
1263 		if (LF_ISSET(TXT_BEAUTIFY) && iscntrl(evp->e_c) &&
1264 		    evp->e_value != K_FORMFEED && evp->e_value != K_TAB) {
1265 			msgq(sp, M_BERR,
1266 			    "192|Illegal character; quote to enter");
1267 			if (LF_ISSET(TXT_REPLAY))
1268 				goto done;
1269 			break;
1270 		}
1271 
1272 insq_ch:	/*
1273 		 * If entering a non-word character after a word, check for
1274 		 * abbreviations.  If there was one, discard replay characters.
1275 		 * If entering a blank character, check for unmap commands,
1276 		 * as well.
1277 		 */
1278 		if (!inword(evp->e_c)) {
1279 			if (abb == AB_INWORD &&
1280 			    !LF_ISSET(TXT_REPLAY) && F_ISSET(gp, G_ABBREV)) {
1281 				if (txt_abbrev(sp, tp, &evp->e_c,
1282 				    LF_ISSET(TXT_INFOLINE), &tmp, &ab_turnoff))
1283 					goto err;
1284 				if (tmp) {
1285 					if (LF_ISSET(TXT_RECORD))
1286 						rcol -= tmp + 1;
1287 					goto resolve;
1288 				}
1289 			}
1290 			if (isblank(evp->e_c) && UNMAP_TST)
1291 				txt_unmap(sp, tp, &ec_flags);
1292 		}
1293 		if (abb != AB_NOTSET)
1294 			abb = inword(evp->e_c) ? AB_INWORD : AB_NOTWORD;
1295 
1296 insl_ch:	if (txt_insch(sp, tp, &evp->e_c, flags))
1297 			goto err;
1298 
1299 		/*
1300 		 * If we're using K_VLNEXT to quote the next character, then
1301 		 * we want the cursor to position itself on the ^ placeholder
1302 		 * we're displaying, to match historic practice.
1303 		 */
1304 		if (quote == Q_VNEXT) {
1305 			--tp->cno;
1306 			++tp->owrite;
1307 		}
1308 
1309 		/*
1310 		 * !!!
1311 		 * Translate "<CH_HEX>[isxdigit()]*" to a character with
1312 		 * a hex value: this test delimits the value by the max
1313 		 * number of hex bytes.  Offset by one, we use 0 to mean
1314 		 * that we've found <CH_HEX>.
1315 		 */
1316 		if (hexcnt != 0 && hexcnt++ == sizeof(CHAR_T) * 2 + 1) {
1317 			hexcnt = 0;
1318 			if (txt_hex(sp, tp))
1319 				goto err;
1320 		}
1321 
1322 		/*
1323 		 * Check to see if we've crossed the margin.
1324 		 *
1325 		 * !!!
1326 		 * In the historic vi, the wrapmargin value was figured out
1327 		 * using the display widths of the characters, i.e. <tab>
1328 		 * characters were counted as two characters if the list edit
1329 		 * option is set, but as the tabstop edit option number of
1330 		 * characters otherwise.  That's what the vs_column() function
1331 		 * gives us, so we use it.
1332 		 */
1333 		if (margin != 0) {
1334 			if (vs_column(sp, &tcol))
1335 				goto err;
1336 			if (tcol >= margin) {
1337 				if (txt_margin(sp, tp, &wmt, &tmp, flags))
1338 					goto err;
1339 				if (tmp) {
1340 					if (isblank(evp->e_c))
1341 						wm_skip = 1;
1342 					wm_set = 1;
1343 					goto k_cr;
1344 				}
1345 			}
1346 		}
1347 
1348 		/*
1349 		 * If we've reached the end of the buffer, then we need to
1350 		 * switch into insert mode.  This happens when there's a
1351 		 * change to a mark and the user puts in more characters than
1352 		 * the length of the motion.
1353 		 */
1354 ebuf_chk:	if (tp->cno >= tp->len) {
1355 			BINC_GOTO(sp, tp->lb, tp->lb_len, tp->len + 1);
1356 			LF_SET(TXT_APPENDEOL);
1357 
1358 			tp->lb[tp->cno] = CH_CURSOR;
1359 			++tp->insert;
1360 			++tp->len;
1361 		}
1362 
1363 		/* Step the quote state forward. */
1364 		if (quote != Q_NOTSET) {
1365 			if (quote == Q_BNEXT)
1366 				quote = Q_BTHIS;
1367 			if (quote == Q_VNEXT)
1368 				quote = Q_VTHIS;
1369 		}
1370 		break;
1371 	}
1372 
1373 #ifdef DEBUG
1374 	if (tp->cno + tp->insert + tp->owrite != tp->len) {
1375 		msgq(sp, M_ERR,
1376 		    "len %u != cno: %u ai: %u insert %u overwrite %u",
1377 		    tp->len, tp->cno, tp->ai, tp->insert, tp->owrite);
1378 		if (LF_ISSET(TXT_REPLAY))
1379 			goto done;
1380 		tp->len = tp->cno + tp->insert + tp->owrite;
1381 	}
1382 #endif
1383 
1384 resolve:/*
1385 	 * 1: If we don't need to know where the cursor really is and we're
1386 	 *    replaying text, keep going.
1387 	 */
1388 	if (margin == 0 && LF_ISSET(TXT_REPLAY))
1389 		goto replay;
1390 
1391 	/*
1392 	 * 2: Reset the line.  Don't bother unless we're about to wait on
1393 	 *    a character or we need to know where the cursor really is.
1394 	 *    We have to do this before showing matching characters so the
1395 	 *    user can see what they're matching.
1396 	 */
1397 	if ((margin != 0 || !KEYS_WAITING(sp)) &&
1398 	    vs_change(sp, tp->lno, LINE_RESET))
1399 		return (1);
1400 
1401 	/*
1402 	 * 3: If there aren't keys waiting, display the matching character.
1403 	 *    We have to do this before resolving any messages, otherwise
1404 	 *    the error message from a missing match won't appear correctly.
1405 	 */
1406 	if (showmatch) {
1407 		if (!KEYS_WAITING(sp) && txt_showmatch(sp, tp))
1408 			return (1);
1409 		showmatch = 0;
1410 	}
1411 
1412 	/*
1413 	 * 4: If there have been messages and we're not editing on the colon
1414 	 *    command line or doing file name completion, resolve them.
1415 	 */
1416 	if ((vip->totalcount != 0 || F_ISSET(gp, G_BELLSCHED)) &&
1417 	    !F_ISSET(sp, SC_TINPUT_INFO) && !filec_redraw &&
1418 	    vs_resolve(sp, NULL, 0))
1419 		return (1);
1420 
1421 	/*
1422 	 * 5: Refresh the screen if we're about to wait on a character or we
1423 	 *    need to know where the cursor really is.
1424 	 */
1425 	if (margin != 0 || !KEYS_WAITING(sp)) {
1426 		UPDATE_POSITION(sp, tp);
1427 		if (vs_refresh(sp, margin != 0))
1428 			return (1);
1429 	}
1430 
1431 	/* 6: Proceed with the incremental search. */
1432 	if (FL_ISSET(is_flags, IS_RUNNING) && txt_isrch(sp, vp, tp, &is_flags))
1433 		return (1);
1434 
1435 	/* 7: Next character... */
1436 	if (LF_ISSET(TXT_REPLAY))
1437 		goto replay;
1438 	goto next;
1439 
1440 done:	/* Leave input mode. */
1441 	F_CLR(sp, SC_TINPUT);
1442 
1443 	/* If recording for playback, save it. */
1444 	if (LF_ISSET(TXT_RECORD))
1445 		vip->rep_cnt = rcol;
1446 
1447 	/*
1448 	 * If not working on the colon command line, set the final cursor
1449 	 * position.
1450 	 */
1451 	if (!F_ISSET(sp, SC_TINPUT_INFO)) {
1452 		vp->m_final.lno = tp->lno;
1453 		vp->m_final.cno = tp->cno;
1454 	}
1455 	return (0);
1456 
1457 err:
1458 alloc_err:
1459 	txt_err(sp, &sp->tiq);
1460 	return (1);
1461 }
1462 
1463 /*
1464  * txt_abbrev --
1465  *	Handle abbreviations.
1466  */
1467 static int
1468 txt_abbrev(sp, tp, pushcp, isinfoline, didsubp, turnoffp)
1469 	SCR *sp;
1470 	TEXT *tp;
1471 	CHAR_T *pushcp;
1472 	int isinfoline, *didsubp, *turnoffp;
1473 {
1474 	VI_PRIVATE *vip;
1475 	CHAR_T ch, *p;
1476 	SEQ *qp;
1477 	size_t len, off;
1478 
1479 	/* Check to make sure we're not at the start of an append. */
1480 	*didsubp = 0;
1481 	if (tp->cno == tp->offset)
1482 		return (0);
1483 
1484 	vip = VIP(sp);
1485 
1486 	/*
1487 	 * Find the start of the "word".
1488 	 *
1489 	 * !!!
1490 	 * We match historic practice, which, as far as I can tell, had an
1491 	 * off-by-one error.  The way this worked was that when the inserted
1492 	 * text switched from a "word" character to a non-word character,
1493 	 * vi would check for possible abbreviations.  It would then take the
1494 	 * type (i.e. word/non-word) of the character entered TWO characters
1495 	 * ago, and move backward in the text until reaching a character that
1496 	 * was not that type, or the beginning of the insert, the line, or
1497 	 * the file.  For example, in the string "abc<space>", when the <space>
1498 	 * character triggered the abbreviation check, the type of the 'b'
1499 	 * character was used for moving through the string.  Maybe there's a
1500 	 * reason for not using the first (i.e. 'c') character, but I can't
1501 	 * think of one.
1502 	 *
1503 	 * Terminate at the beginning of the insert or the character after the
1504 	 * offset character -- both can be tested for using tp->offset.
1505 	 */
1506 	off = tp->cno - 1;			/* Previous character. */
1507 	p = tp->lb + off;
1508 	len = 1;				/* One character test. */
1509 	if (off == tp->offset || isblank(p[-1]))
1510 		goto search;
1511 	if (inword(p[-1]))			/* Move backward to change. */
1512 		for (;;) {
1513 			--off; --p; ++len;
1514 			if (off == tp->offset || !inword(p[-1]))
1515 				break;
1516 		}
1517 	else
1518 		for (;;) {
1519 			--off; --p; ++len;
1520 			if (off == tp->offset ||
1521 			    inword(p[-1]) || isblank(p[-1]))
1522 				break;
1523 		}
1524 
1525 	/*
1526 	 * !!!
1527 	 * Historic vi exploded abbreviations on the command line.  This has
1528 	 * obvious problems in that unabbreviating the string can be extremely
1529 	 * tricky, particularly if the string has, say, an embedded escape
1530 	 * character.  Personally, I think it's a stunningly bad idea.  Other
1531 	 * examples of problems this caused in historic vi are:
1532 	 *	:ab foo bar
1533 	 *	:ab foo baz
1534 	 * results in "bar" being abbreviated to "baz", which wasn't what the
1535 	 * user had in mind at all.  Also, the commands:
1536 	 *	:ab foo bar
1537 	 *	:unab foo<space>
1538 	 * resulted in an error message that "bar" wasn't mapped.  Finally,
1539 	 * since the string was already exploded by the time the unabbreviate
1540 	 * command got it, all it knew was that an abbreviation had occurred.
1541 	 * Cleverly, it checked the replacement string for its unabbreviation
1542 	 * match, which meant that the commands:
1543 	 *	:ab foo1 bar
1544 	 *	:ab foo2 bar
1545 	 *	:unab foo2
1546 	 * unabbreviate "foo1", and the commands:
1547 	 *	:ab foo bar
1548 	 *	:ab bar baz
1549 	 * unabbreviate "foo"!
1550 	 *
1551 	 * Anyway, people neglected to first ask my opinion before they wrote
1552 	 * macros that depend on this stuff, so, we make this work as follows.
1553 	 * When checking for an abbreviation on the command line, if we get a
1554 	 * string which is <blank> terminated and which starts at the beginning
1555 	 * of the line, we check to see it is the abbreviate or unabbreviate
1556 	 * commands.  If it is, turn abbreviations off and return as if no
1557 	 * abbreviation was found.  Note also, minor trickiness, so that if
1558 	 * the user erases the line and starts another command, we turn the
1559 	 * abbreviations back on.
1560 	 *
1561 	 * This makes the layering look like a Nachos Supreme.
1562 	 */
1563 search:	if (isinfoline)
1564 		if (off == tp->ai || off == tp->offset)
1565 			if (ex_is_abbrev(p, len)) {
1566 				*turnoffp = 1;
1567 				return (0);
1568 			} else
1569 				*turnoffp = 0;
1570 		else
1571 			if (*turnoffp)
1572 				return (0);
1573 
1574 	/* Check for any abbreviations. */
1575 	if ((qp = seq_find(sp, NULL, NULL, p, len, SEQ_ABBREV, NULL)) == NULL)
1576 		return (0);
1577 
1578 	/*
1579 	 * Push the abbreviation onto the tty stack.  Historically, characters
1580 	 * resulting from an abbreviation expansion were themselves subject to
1581 	 * map expansions, O_SHOWMATCH matching etc.  This means the expanded
1582 	 * characters will be re-tested for abbreviations.  It's difficult to
1583 	 * know what historic practice in this case was, since abbreviations
1584 	 * were applied to :colon command lines, so entering abbreviations that
1585 	 * looped was tricky, although possible.  In addition, obvious loops
1586 	 * didn't work as expected.  (The command ':ab a b|ab b c|ab c a' will
1587 	 * silently only implement and/or display the last abbreviation.)
1588 	 *
1589 	 * This implementation doesn't recover well from such abbreviations.
1590 	 * The main input loop counts abbreviated characters, and, when it
1591 	 * reaches a limit, discards any abbreviated characters on the queue.
1592 	 * It's difficult to back up to the original position, as the replay
1593 	 * queue would have to be adjusted, and the line state when an initial
1594 	 * abbreviated character was received would have to be saved.
1595 	 */
1596 	ch = *pushcp;
1597 	if (v_event_push(sp, NULL, &ch, 1, CH_ABBREVIATED))
1598 		return (1);
1599 	if (v_event_push(sp, NULL, qp->output, qp->olen, CH_ABBREVIATED))
1600 		return (1);
1601 
1602 	/*
1603 	 * If the size of the abbreviation is larger than or equal to the size
1604 	 * of the original text, move to the start of the replaced characters,
1605 	 * and add their length to the overwrite count.
1606 	 *
1607 	 * If the abbreviation is smaller than the original text, we have to
1608 	 * delete the additional overwrite characters and copy down any insert
1609 	 * characters.
1610 	 */
1611 	tp->cno -= len;
1612 	if (qp->olen >= len)
1613 		tp->owrite += len;
1614 	else {
1615 		if (tp->insert)
1616 			memmove(tp->lb + tp->cno + qp->olen,
1617 			    tp->lb + tp->cno + tp->owrite + len, tp->insert);
1618 		tp->owrite += qp->olen;
1619 		tp->len -= len - qp->olen;
1620 	}
1621 
1622 	/*
1623 	 * We return the length of the abbreviated characters.  This is so
1624 	 * the calling routine can replace the replay characters with the
1625 	 * abbreviation.  This means that subsequent '.' commands will produce
1626 	 * the same text, regardless of intervening :[un]abbreviate commands.
1627 	 * This is historic practice.
1628 	 */
1629 	*didsubp = len;
1630 	return (0);
1631 }
1632 
1633 /*
1634  * txt_unmap --
1635  *	Handle the unmap command.
1636  */
1637 static void
1638 txt_unmap(sp, tp, ec_flagsp)
1639 	SCR *sp;
1640 	TEXT *tp;
1641 	u_int32_t *ec_flagsp;
1642 {
1643 	size_t len, off;
1644 	char *p;
1645 
1646 	/* Find the beginning of this "word". */
1647 	for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --p, --off) {
1648 		if (isblank(*p)) {
1649 			++p;
1650 			break;
1651 		}
1652 		++len;
1653 		if (off == tp->ai || off == tp->offset)
1654 			break;
1655 	}
1656 
1657 	/*
1658 	 * !!!
1659 	 * Historic vi exploded input mappings on the command line.  See the
1660 	 * txt_abbrev() routine for an explanation of the problems inherent
1661 	 * in this.
1662 	 *
1663 	 * We make this work as follows.  If we get a string which is <blank>
1664 	 * terminated and which starts at the beginning of the line, we check
1665 	 * to see it is the unmap command.  If it is, we return that the input
1666 	 * mapping should be turned off.  Note also, minor trickiness, so that
1667 	 * if the user erases the line and starts another command, we go ahead
1668 	 * an turn mapping back on.
1669 	 */
1670 	if ((off == tp->ai || off == tp->offset) && ex_is_unmap(p, len))
1671 		FL_CLR(*ec_flagsp, EC_MAPINPUT);
1672 	else
1673 		FL_SET(*ec_flagsp, EC_MAPINPUT);
1674 }
1675 
1676 /*
1677  * txt_ai_resolve --
1678  *	When a line is resolved by <esc>, review autoindent characters.
1679  */
1680 static void
1681 txt_ai_resolve(sp, tp, changedp)
1682 	SCR *sp;
1683 	TEXT *tp;
1684 	int *changedp;
1685 {
1686 	u_long ts;
1687 	int del;
1688 	size_t cno, len, new, old, scno, spaces, tab_after_sp, tabs;
1689 	char *p;
1690 
1691 	*changedp = 0;
1692 
1693 	/*
1694 	 * If the line is empty, has an offset, or no autoindent
1695 	 * characters, we're done.
1696 	 */
1697 	if (!tp->len || tp->offset || !tp->ai)
1698 		return;
1699 
1700 	/*
1701 	 * If the length is less than or equal to the autoindent
1702 	 * characters, delete them.
1703 	 */
1704 	if (tp->len <= tp->ai) {
1705 		tp->ai = tp->cno = tp->len = 0;
1706 		return;
1707 	}
1708 
1709 	/*
1710 	 * The autoindent characters plus any leading <blank> characters
1711 	 * in the line are resolved into the minimum number of characters.
1712 	 * Historic practice.
1713 	 */
1714 	ts = O_VAL(sp, O_TABSTOP);
1715 
1716 	/* Figure out the last <blank> screen column. */
1717 	for (p = tp->lb, scno = 0, len = tp->len,
1718 	    spaces = tab_after_sp = 0; len-- && isblank(*p); ++p)
1719 		if (*p == '\t') {
1720 			if (spaces)
1721 				tab_after_sp = 1;
1722 			scno += COL_OFF(scno, ts);
1723 		} else {
1724 			++spaces;
1725 			++scno;
1726 		}
1727 
1728 	/*
1729 	 * If there are no spaces, or no tabs after spaces and less than
1730 	 * ts spaces, it's already minimal.
1731 	 */
1732 	if (!spaces || !tab_after_sp && spaces < ts)
1733 		return;
1734 
1735 	/* Count up spaces/tabs needed to get to the target. */
1736 	for (cno = 0, tabs = 0; cno + COL_OFF(cno, ts) <= scno; ++tabs)
1737 		cno += COL_OFF(cno, ts);
1738 	spaces = scno - cno;
1739 
1740 	/*
1741 	 * Figure out how many characters we're dropping -- if we're not
1742 	 * dropping any, it's already minimal, we're done.
1743 	 */
1744 	old = p - tp->lb;
1745 	new = spaces + tabs;
1746 	if (old == new)
1747 		return;
1748 
1749 	/* Shift the rest of the characters down, adjust the counts. */
1750 	del = old - new;
1751 	memmove(p - del, p, tp->len - old);
1752 	tp->len -= del;
1753 	tp->cno -= del;
1754 
1755 	/* Fill in space/tab characters. */
1756 	for (p = tp->lb; tabs--;)
1757 		*p++ = '\t';
1758 	while (spaces--)
1759 		*p++ = ' ';
1760 	*changedp = 1;
1761 }
1762 
1763 /*
1764  * v_txt_auto --
1765  *	Handle autoindent.  If aitp isn't NULL, use it, otherwise,
1766  *	retrieve the line.
1767  *
1768  * PUBLIC: int v_txt_auto __P((SCR *, recno_t, TEXT *, size_t, TEXT *));
1769  */
1770 int
1771 v_txt_auto(sp, lno, aitp, len, tp)
1772 	SCR *sp;
1773 	recno_t lno;
1774 	TEXT *aitp, *tp;
1775 	size_t len;
1776 {
1777 	size_t nlen;
1778 	char *p, *t;
1779 
1780 	if (aitp == NULL) {
1781 		/*
1782 		 * If the ex append command is executed with an address of 0,
1783 		 * it's possible to get here with a line number of 0.  Return
1784 		 * an indent of 0.
1785 		 */
1786 		if (lno == 0) {
1787 			tp->ai = 0;
1788 			return (0);
1789 		}
1790 		if (db_get(sp, lno, DBG_FATAL, &t, &len))
1791 			return (1);
1792 	} else
1793 		t = aitp->lb;
1794 
1795 	/* Count whitespace characters. */
1796 	for (p = t; len > 0; ++p, --len)
1797 		if (!isblank(*p))
1798 			break;
1799 
1800 	/* Set count, check for no indentation. */
1801 	if ((nlen = (p - t)) == 0)
1802 		return (0);
1803 
1804 	/* Make sure the buffer's big enough. */
1805 	BINC_RET(sp, tp->lb, tp->lb_len, tp->len + nlen);
1806 
1807 	/* Copy the buffer's current contents up. */
1808 	if (tp->len != 0)
1809 		memmove(tp->lb + nlen, tp->lb, tp->len);
1810 	tp->len += nlen;
1811 
1812 	/* Copy the indentation into the new buffer. */
1813 	memmove(tp->lb, t, nlen);
1814 
1815 	/* Set the autoindent count. */
1816 	tp->ai = nlen;
1817 	return (0);
1818 }
1819 
1820 /*
1821  * txt_backup --
1822  *	Back up to the previously edited line.
1823  */
1824 static TEXT *
1825 txt_backup(sp, tiqh, tp, flagsp)
1826 	SCR *sp;
1827 	TEXTH *tiqh;
1828 	TEXT *tp;
1829 	u_int32_t *flagsp;
1830 {
1831 	VI_PRIVATE *vip;
1832 	TEXT *ntp;
1833 
1834 	/* Get a handle on the previous TEXT structure. */
1835 	if ((ntp = tp->q.cqe_prev) == (void *)tiqh) {
1836 		if (!FL_ISSET(*flagsp, TXT_REPLAY))
1837 			msgq(sp, M_BERR,
1838 			    "193|Already at the beginning of the insert");
1839 		return (tp);
1840 	}
1841 
1842 	/* Bookkeeping. */
1843 	ntp->len = ntp->sv_len;
1844 
1845 	/* Handle appending to the line. */
1846 	vip = VIP(sp);
1847 	if (ntp->owrite == 0 && ntp->insert == 0) {
1848 		ntp->lb[ntp->len] = CH_CURSOR;
1849 		++ntp->insert;
1850 		++ntp->len;
1851 		FL_SET(*flagsp, TXT_APPENDEOL);
1852 	} else
1853 		FL_CLR(*flagsp, TXT_APPENDEOL);
1854 
1855 	/* Release the current TEXT. */
1856 	CIRCLEQ_REMOVE(tiqh, tp, q);
1857 	text_free(tp);
1858 
1859 	/* Update the old line on the screen. */
1860 	if (vs_change(sp, ntp->lno + 1, LINE_DELETE))
1861 		return (NULL);
1862 
1863 	/* Return the new/current TEXT. */
1864 	return (ntp);
1865 }
1866 
1867 /*
1868  * Text indentation is truly strange.  ^T and ^D do movements to the next or
1869  * previous shiftwidth value, i.e. for a 1-based numbering, with shiftwidth=3,
1870  * ^T moves a cursor on the 7th, 8th or 9th column to the 10th column, and ^D
1871  * moves it back.
1872  *
1873  * !!!
1874  * The ^T and ^D characters in historical vi had special meaning only when they
1875  * were the first characters entered after entering text input mode.  As normal
1876  * erase characters couldn't erase autoindent characters (^T in this case), it
1877  * meant that inserting text into previously existing text was strange -- ^T
1878  * only worked if it was the first keystroke(s), and then could only be erased
1879  * using ^D.  This implementation treats ^T specially anywhere it occurs in the
1880  * input, and permits the standard erase characters to erase the characters it
1881  * inserts.
1882  *
1883  * !!!
1884  * A fun test is to try:
1885  *	:se sw=4 ai list
1886  *	i<CR>^Tx<CR>^Tx<CR>^Tx<CR>^Dx<CR>^Dx<CR>^Dx<esc>
1887  * Historic vi loses some of the '$' marks on the line ends, but otherwise gets
1888  * it right.
1889  *
1890  * XXX
1891  * Technically, txt_dent should be part of the screen interface, as it requires
1892  * knowledge of character sizes, including <space>s, on the screen.  It's here
1893  * because it's a complicated little beast, and I didn't want to shove it down
1894  * into the screen.  It's probable that KEY_LEN will call into the screen once
1895  * there are screens with different character representations.
1896  *
1897  * txt_dent --
1898  *	Handle ^T indents, ^D outdents.
1899  *
1900  * If anything changes here, check the ex version to see if it needs similar
1901  * changes.
1902  */
1903 static int
1904 txt_dent(sp, tp, isindent)
1905 	SCR *sp;
1906 	TEXT *tp;
1907 	int isindent;
1908 {
1909 	CHAR_T ch;
1910 	u_long sw, ts;
1911 	size_t cno, current, spaces, target, tabs, off;
1912 	int ai_reset;
1913 
1914 	ts = O_VAL(sp, O_TABSTOP);
1915 	sw = O_VAL(sp, O_SHIFTWIDTH);
1916 
1917 	/*
1918 	 * Since we don't know what precedes the character(s) being inserted
1919 	 * (or deleted), the preceding whitespace characters must be resolved.
1920 	 * An example is a <tab>, which doesn't need a full shiftwidth number
1921 	 * of columns because it's preceded by <space>s.  This is easy to get
1922 	 * if the user sets shiftwidth to a value less than tabstop (or worse,
1923 	 * something for which tabstop isn't a multiple) and then uses ^T to
1924 	 * indent, and ^D to outdent.
1925 	 *
1926 	 * Figure out the current and target screen columns.  In the historic
1927 	 * vi, the autoindent column was NOT determined using display widths
1928 	 * of characters as was the wrapmargin column.  For that reason, we
1929 	 * can't use the vs_column() function, but have to calculate it here.
1930 	 * This is slow, but it's normally only on the first few characters of
1931 	 * a line.
1932 	 */
1933 	for (current = cno = 0; cno < tp->cno; ++cno)
1934 		current += tp->lb[cno] == '\t' ?
1935 		    COL_OFF(current, ts) : KEY_LEN(sp, tp->lb[cno]);
1936 
1937 	target = current;
1938 	if (isindent)
1939 		target += COL_OFF(target, sw);
1940 	else
1941 		target -= --target % sw;
1942 
1943 	/*
1944 	 * The AI characters will be turned into overwrite characters if the
1945 	 * cursor immediately follows them.  We test both the cursor position
1946 	 * and the indent flag because there's no single test.  (^T can only
1947 	 * be detected by the cursor position, and while we know that the test
1948 	 * is always true for ^D, the cursor can be in more than one place, as
1949 	 * "0^D" and "^D" are different.)
1950 	 */
1951 	ai_reset = !isindent || tp->cno == tp->ai + tp->offset;
1952 
1953 	/*
1954 	 * Back up over any previous <blank> characters, changing them into
1955 	 * overwrite characters (including any ai characters).  Then figure
1956 	 * out the current screen column.
1957 	 */
1958 	for (; tp->cno > tp->offset &&
1959 	    (tp->lb[tp->cno - 1] == ' ' || tp->lb[tp->cno - 1] == '\t');
1960 	    --tp->cno, ++tp->owrite);
1961 	for (current = cno = 0; cno < tp->cno; ++cno)
1962 		current += tp->lb[cno] == '\t' ?
1963 		    COL_OFF(current, ts) : KEY_LEN(sp, tp->lb[cno]);
1964 
1965 	/*
1966 	 * If we didn't move up to or past the target, it's because there
1967 	 * weren't enough characters to delete, e.g. the first character
1968 	 * of the line was a tp->offset character, and the user entered
1969 	 * ^D to move to the beginning of a line.  An example of this is:
1970 	 *
1971 	 *	:set ai sw=4<cr>i<space>a<esc>i^T^D
1972 	 *
1973 	 * Otherwise, count up the total spaces/tabs needed to get from the
1974 	 * beginning of the line (or the last non-<blank> character) to the
1975 	 * target.
1976 	 */
1977 	if (current >= target)
1978 		spaces = tabs = 0;
1979 	else {
1980 		for (cno = current,
1981 		    tabs = 0; cno + COL_OFF(cno, ts) <= target; ++tabs)
1982 			cno += COL_OFF(cno, ts);
1983 		spaces = target - cno;
1984 	}
1985 
1986 	/* If we overwrote ai characters, reset the ai count. */
1987 	if (ai_reset)
1988 		tp->ai = tabs + spaces;
1989 
1990 	/*
1991 	 * Call txt_insch() to insert each character, so that we get the
1992 	 * correct effect when we add a <tab> to replace N <spaces>.
1993 	 */
1994 	for (ch = '\t'; tabs > 0; --tabs)
1995 		(void)txt_insch(sp, tp, &ch, 0);
1996 	for (ch = ' '; spaces > 0; --spaces)
1997 		(void)txt_insch(sp, tp, &ch, 0);
1998 	return (0);
1999 }
2000 
2001 /*
2002  * txt_fc --
2003  *	File name completion.
2004  */
2005 static int
2006 txt_fc(sp, tp, redrawp)
2007 	SCR *sp;
2008 	TEXT *tp;
2009 	int *redrawp;
2010 {
2011 	struct stat sb;
2012 	ARGS **argv;
2013 	CHAR_T s_ch;
2014 	EXCMD cmd;
2015 	size_t indx, len, nlen, off;
2016 	int argc, trydir;
2017 	char *p, *t;
2018 
2019 	trydir = 0;
2020 	*redrawp = 0;
2021 
2022 	/*
2023 	 * Find the beginning of this "word" -- if we're at the beginning
2024 	 * of the line, it's a special case.
2025 	 */
2026 	if (tp->cno == 1) {
2027 		len = 0;
2028 		p = tp->lb;
2029 	} else
2030 retry:		for (len = 0,
2031 		    off = tp->cno - 1, p = tp->lb + off;; --off, --p) {
2032 			if (isblank(*p)) {
2033 				++p;
2034 				break;
2035 			}
2036 			++len;
2037 			if (off == tp->ai || off == tp->offset)
2038 				break;
2039 		}
2040 
2041 	/*
2042 	 * Get enough space for a wildcard character.
2043 	 *
2044 	 * XXX
2045 	 * This won't work for "foo\", since the \ will escape the expansion
2046 	 * character.  I'm not sure if that's a bug or not...
2047 	 */
2048 	off = p - tp->lb;
2049 	BINC_RET(sp, tp->lb, tp->lb_len, tp->len + 1);
2050 	p = tp->lb + off;
2051 
2052 	s_ch = p[len];
2053 	p[len] = '*';
2054 
2055 	/* Build an ex command, and call the ex expansion routines. */
2056 	ex_cinit(&cmd, 0, 0, OOBLNO, OOBLNO, 0, NULL);
2057 	if (argv_init(sp, &cmd))
2058 		return (1);
2059 	if (argv_exp2(sp, &cmd, p, len + 1)) {
2060 		p[len] = s_ch;
2061 		return (0);
2062 	}
2063 	argc = cmd.argc;
2064 	argv = cmd.argv;
2065 
2066 	p[len] = s_ch;
2067 
2068 	switch (argc) {
2069 	case 0:				/* No matches. */
2070 		if (!trydir)
2071 			(void)sp->gp->scr_bell(sp);
2072 		return (0);
2073 	case 1:				/* One match. */
2074 		/* If something changed, do the exchange. */
2075 		nlen = strlen(cmd.argv[0]->bp);
2076 		if (len != nlen || memcmp(cmd.argv[0]->bp, p, len))
2077 			break;
2078 
2079 		/* If haven't done a directory test, do it now. */
2080 		if (!trydir &&
2081 		    !stat(cmd.argv[0]->bp, &sb) && S_ISDIR(sb.st_mode)) {
2082 			p += len;
2083 			goto isdir;
2084 		}
2085 
2086 		/* If nothing changed, period, ring the bell. */
2087 		if (!trydir)
2088 			(void)sp->gp->scr_bell(sp);
2089 		return (0);
2090 	default:			/* Multiple matches. */
2091 		*redrawp = 1;
2092 		if (txt_fc_col(sp, argc, argv))
2093 			return (1);
2094 
2095 		/* Find the length of the shortest match. */
2096 		for (nlen = cmd.argv[0]->len; --argc > 0;) {
2097 			if (cmd.argv[argc]->len < nlen)
2098 				nlen = cmd.argv[argc]->len;
2099 			for (indx = 0; indx < nlen &&
2100 			    cmd.argv[argc]->bp[indx] == cmd.argv[0]->bp[indx];
2101 			    ++indx);
2102 			nlen = indx;
2103 		}
2104 		break;
2105 	}
2106 
2107 	/* Overwrite the expanded text first. */
2108 	for (t = cmd.argv[0]->bp; len > 0 && nlen > 0; --len, --nlen)
2109 		*p++ = *t++;
2110 
2111 	/* If lost text, make the remaining old text overwrite characters. */
2112 	if (len) {
2113 		tp->cno -= len;
2114 		tp->owrite += len;
2115 	}
2116 
2117 	/* Overwrite any overwrite characters next. */
2118 	for (; nlen > 0 && tp->owrite > 0; --nlen, --tp->owrite, ++tp->cno)
2119 		*p++ = *t++;
2120 
2121 	/* Shift remaining text up, and move the cursor to the end. */
2122 	if (nlen) {
2123 		off = p - tp->lb;
2124 		BINC_RET(sp, tp->lb, tp->lb_len, tp->len + nlen);
2125 		p = tp->lb + off;
2126 
2127 		tp->cno += nlen;
2128 		tp->len += nlen;
2129 
2130 		if (tp->insert != 0)
2131 			(void)memmove(p + nlen, p, tp->insert);
2132 		while (nlen--)
2133 			*p++ = *t++;
2134 	}
2135 
2136 	/* If a single match and it's a directory, retry it. */
2137 	if (argc == 1 && !stat(cmd.argv[0]->bp, &sb) && S_ISDIR(sb.st_mode)) {
2138 isdir:		if (tp->owrite == 0) {
2139 			off = p - tp->lb;
2140 			BINC_RET(sp, tp->lb, tp->lb_len, tp->len + 1);
2141 			p = tp->lb + off;
2142 			if (tp->insert != 0)
2143 				(void)memmove(p + 1, p, tp->insert);
2144 			++tp->len;
2145 		} else
2146 			--tp->owrite;
2147 
2148 		++tp->cno;
2149 		*p++ = '/';
2150 
2151 		trydir = 1;
2152 		goto retry;
2153 	}
2154 	return (0);
2155 }
2156 
2157 /*
2158  * txt_fc_col --
2159  *	Display file names for file name completion.
2160  */
2161 static int
2162 txt_fc_col(sp, argc, argv)
2163 	SCR *sp;
2164 	int argc;
2165 	ARGS **argv;
2166 {
2167 	ARGS **av;
2168 	CHAR_T *p;
2169 	GS *gp;
2170 	size_t base, cnt, col, colwidth, numrows, numcols, prefix, row;
2171 	int ac, nf, reset;
2172 
2173 	gp = sp->gp;
2174 
2175 	/* Trim any directory prefix common to all of the files. */
2176 	if ((p = strrchr(argv[0]->bp, '/')) == NULL)
2177 		prefix = 0;
2178 	else {
2179 		prefix = (p - argv[0]->bp) + 1;
2180 		for (ac = argc - 1, av = argv + 1; ac > 0; --ac, ++av)
2181 			if (av[0]->len < prefix ||
2182 			    memcmp(av[0]->bp, argv[0]->bp, prefix)) {
2183 				prefix = 0;
2184 				break;
2185 			}
2186 	}
2187 
2188 	/*
2189 	 * Figure out the column width for the longest name.  Output is done on
2190 	 * 6 character "tab" boundaries for no particular reason.  (Since we
2191 	 * don't output tab characters, we ignore the terminal's tab settings.)
2192 	 * Ignore the user's tab setting because we have no idea how reasonable
2193 	 * it is.
2194 	 */
2195 	for (ac = argc, av = argv, colwidth = 0; ac > 0; --ac, ++av) {
2196 		for (col = 0, p = av[0]->bp + prefix; *p != '\0'; ++p)
2197 			col += KEY_LEN(sp, *p);
2198 		if (col > colwidth)
2199 			colwidth = col;
2200 	}
2201 	colwidth += COL_OFF(colwidth, 6);
2202 
2203 	/*
2204 	 * Writing to the bottom line of the screen is always turned off when
2205 	 * SC_TINPUT_INFO is set.  Turn it back on, we know what we're doing.
2206 	 */
2207 	if (F_ISSET(sp, SC_TINPUT_INFO)) {
2208 		reset = 1;
2209 		F_CLR(sp, SC_TINPUT_INFO);
2210 	} else
2211 		reset = 0;
2212 
2213 #define	CHK_INTR							\
2214 	if (F_ISSET(gp, G_INTERRUPTED))					\
2215 		goto intr;
2216 
2217 	/* If the largest file name is too large, just print them. */
2218 	if (colwidth > sp->cols) {
2219 		p = msg_print(sp, av[0]->bp + prefix, &nf);
2220 		for (ac = argc, av = argv; ac > 0; --ac, ++av) {
2221 			(void)ex_printf(sp, "%s\n", p);
2222 			if (F_ISSET(gp, G_INTERRUPTED))
2223 				break;
2224 		}
2225 		if (nf)
2226 			FREE_SPACE(sp, p, 0);
2227 		CHK_INTR;
2228 	} else {
2229 		/* Figure out the number of columns. */
2230 		numcols = (sp->cols - 1) / colwidth;
2231 		if (argc > numcols) {
2232 			numrows = argc / numcols;
2233 			if (argc % numcols)
2234 				++numrows;
2235 		} else
2236 			numrows = 1;
2237 
2238 		/* Display the files in sorted order. */
2239 		for (row = 0; row < numrows; ++row) {
2240 			for (base = row, col = 0; col < numcols; ++col) {
2241 				p = msg_print(sp, argv[base]->bp + prefix, &nf);
2242 				cnt = ex_printf(sp, "%s", p);
2243 				if (nf)
2244 					FREE_SPACE(sp, p, 0);
2245 				CHK_INTR;
2246 				if ((base += numrows) >= argc)
2247 					break;
2248 				(void)ex_printf(sp,
2249 				    "%*s", (int)(colwidth - cnt), "");
2250 				CHK_INTR;
2251 			}
2252 			(void)ex_puts(sp, "\n");
2253 			CHK_INTR;
2254 		}
2255 		(void)ex_puts(sp, "\n");
2256 		CHK_INTR;
2257 	}
2258 	(void)ex_fflush(sp);
2259 
2260 	if (0) {
2261 intr:		F_CLR(gp, G_INTERRUPTED);
2262 	}
2263 	if (reset)
2264 		F_SET(sp, SC_TINPUT_INFO);
2265 
2266 	return (0);
2267 }
2268 
2269 /*
2270  * txt_emark --
2271  *	Set the end mark on the line.
2272  */
2273 static int
2274 txt_emark(sp, tp, cno)
2275 	SCR *sp;
2276 	TEXT *tp;
2277 	size_t cno;
2278 {
2279 	CHAR_T ch, *kp;
2280 	size_t chlen, nlen, olen;
2281 	char *p;
2282 
2283 	ch = CH_ENDMARK;
2284 
2285 	/*
2286 	 * The end mark may not be the same size as the current character.
2287 	 * Don't let the line shift.
2288 	 */
2289 	nlen = KEY_LEN(sp, ch);
2290 	if (tp->lb[cno] == '\t')
2291 		(void)vs_columns(sp, tp->lb, tp->lno, &cno, &olen);
2292 	else
2293 		olen = KEY_LEN(sp, tp->lb[cno]);
2294 
2295 	/*
2296 	 * If the line got longer, well, it's weird, but it's easy.  If
2297 	 * it's the same length, it's easy.  If it got shorter, we have
2298 	 * to fix it up.
2299 	 */
2300 	if (olen > nlen) {
2301 		BINC_RET(sp, tp->lb, tp->lb_len, tp->len + olen);
2302 		chlen = olen - nlen;
2303 		if (tp->insert != 0)
2304 			memmove(tp->lb + cno + 1 + chlen,
2305 			    tp->lb + cno + 1, tp->insert);
2306 
2307 		tp->len += chlen;
2308 		tp->owrite += chlen;
2309 		p = tp->lb + cno;
2310 		if (tp->lb[cno] == '\t')
2311 			for (cno += chlen; chlen--;)
2312 				*p++ = ' ';
2313 		else
2314 			for (kp = KEY_NAME(sp, tp->lb[cno]),
2315 			    cno += chlen; chlen--;)
2316 				*p++ = *kp++;
2317 	}
2318 	tp->lb[cno] = ch;
2319 	return (vs_change(sp, tp->lno, LINE_RESET));
2320 }
2321 
2322 /*
2323  * txt_err --
2324  *	Handle an error during input processing.
2325  */
2326 static void
2327 txt_err(sp, tiqh)
2328 	SCR *sp;
2329 	TEXTH *tiqh;
2330 {
2331 	recno_t lno;
2332 
2333 	/*
2334 	 * The problem with input processing is that the cursor is at an
2335 	 * indeterminate position since some input may have been lost due
2336 	 * to a malloc error.  So, try to go back to the place from which
2337 	 * the cursor started, knowing that it may no longer be available.
2338 	 *
2339 	 * We depend on at least one line number being set in the text
2340 	 * chain.
2341 	 */
2342 	for (lno = tiqh->cqh_first->lno;
2343 	    !db_exist(sp, lno) && lno > 0; --lno);
2344 
2345 	sp->lno = lno == 0 ? 1 : lno;
2346 	sp->cno = 0;
2347 
2348 	/* Redraw the screen, just in case. */
2349 	F_SET(sp, SC_SCR_REDRAW);
2350 }
2351 
2352 /*
2353  * txt_hex --
2354  *	Let the user insert any character value they want.
2355  *
2356  * !!!
2357  * This is an extension.  The pattern "^X[0-9a-fA-F]*" is a way
2358  * for the user to specify a character value which their keyboard
2359  * may not be able to enter.
2360  */
2361 static int
2362 txt_hex(sp, tp)
2363 	SCR *sp;
2364 	TEXT *tp;
2365 {
2366 	CHAR_T savec;
2367 	size_t len, off;
2368 	u_long value;
2369 	char *p, *wp;
2370 
2371 	/*
2372 	 * Null-terminate the string.  Since nul isn't a legal hex value,
2373 	 * this should be okay, and lets us use a local routine, which
2374 	 * presumably understands the character set, to convert the value.
2375 	 */
2376 	savec = tp->lb[tp->cno];
2377 	tp->lb[tp->cno] = 0;
2378 
2379 	/* Find the previous CH_HEX character. */
2380 	for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --p, --off, ++len) {
2381 		if (*p == CH_HEX) {
2382 			wp = p + 1;
2383 			break;
2384 		}
2385 		/* Not on this line?  Shouldn't happen. */
2386 		if (off == tp->ai || off == tp->offset)
2387 			goto nothex;
2388 	}
2389 
2390 	/* If length of 0, then it wasn't a hex value. */
2391 	if (len == 0)
2392 		goto nothex;
2393 
2394 	/* Get the value. */
2395 	errno = 0;
2396 	value = strtol(wp, NULL, 16);
2397 	if (errno || value > MAX_CHAR_T) {
2398 nothex:		tp->lb[tp->cno] = savec;
2399 		return (0);
2400 	}
2401 
2402 	/* Restore the original character. */
2403 	tp->lb[tp->cno] = savec;
2404 
2405 	/* Adjust the bookkeeping. */
2406 	tp->cno -= len;
2407 	tp->len -= len;
2408 	tp->lb[tp->cno - 1] = value;
2409 
2410 	/* Copy down any overwrite characters. */
2411 	if (tp->owrite)
2412 		memmove(tp->lb + tp->cno, tp->lb + tp->cno + len, tp->owrite);
2413 
2414 	/* Copy down any insert characters. */
2415 	if (tp->insert)
2416 		memmove(tp->lb + tp->cno + tp->owrite,
2417 		    tp->lb + tp->cno + tp->owrite + len, tp->insert);
2418 
2419 	return (0);
2420 }
2421 
2422 /*
2423  * txt_insch --
2424  *
2425  * !!!
2426  * Historic vi did a special screen optimization for tab characters.  As an
2427  * example, for the keystrokes "iabcd<esc>0C<tab>", the tab overwrote the
2428  * rest of the string when it was displayed.
2429  *
2430  * Because early versions of this implementation redisplayed the entire line
2431  * on each keystroke, the "bcd" was pushed to the right as it ignored that
2432  * the user had "promised" to change the rest of the characters.  However,
2433  * the historic vi implementation had an even worse bug: given the keystrokes
2434  * "iabcd<esc>0R<tab><esc>", the "bcd" disappears, and magically reappears
2435  * on the second <esc> key.
2436  *
2437  * POSIX 1003.2 requires (will require) that this be fixed, specifying that
2438  * vi overwrite characters the user has committed to changing, on the basis
2439  * of the screen space they require, but that it not overwrite other characters.
2440  */
2441 static int
2442 txt_insch(sp, tp, chp, flags)
2443 	SCR *sp;
2444 	TEXT *tp;
2445 	CHAR_T *chp;
2446 	u_int flags;
2447 {
2448 	CHAR_T *kp, savech;
2449 	size_t chlen, cno, copydown, olen, nlen;
2450 	char *p;
2451 
2452 	/*
2453 	 * The 'R' command does one-for-one replacement, because there's
2454 	 * no way to know how many characters the user intends to replace.
2455 	 */
2456 	if (LF_ISSET(TXT_REPLACE)) {
2457 		if (tp->owrite) {
2458 			--tp->owrite;
2459 			tp->lb[tp->cno++] = *chp;
2460 			return (0);
2461 		}
2462 	} else if (tp->owrite) {		/* Overwrite a character. */
2463 		cno = tp->cno;
2464 
2465 		/*
2466 		 * If the old or new characters are tabs, then the length of the
2467 		 * display depends on the character position in the display.  We
2468 		 * don't even try to handle this here, just ask the screen.
2469 		 */
2470 		if (*chp == '\t') {
2471 			savech = tp->lb[cno];
2472 			tp->lb[cno] = '\t';
2473 			(void)vs_columns(sp, tp->lb, tp->lno, &cno, &nlen);
2474 			tp->lb[cno] = savech;
2475 		} else
2476 			nlen = KEY_LEN(sp, *chp);
2477 
2478 		/*
2479 		 * Eat overwrite characters until we run out of them or we've
2480 		 * handled the length of the new character.  If we only eat
2481 		 * part of an overwrite character, break it into its component
2482 		 * elements and display the remaining components.
2483 		 */
2484 		for (copydown = 0; nlen != 0 && tp->owrite != 0;) {
2485 			--tp->owrite;
2486 
2487 			if (tp->lb[cno] == '\t')
2488 				(void)vs_columns(sp,
2489 				    tp->lb, tp->lno, &cno, &olen);
2490 			else
2491 				olen = KEY_LEN(sp, tp->lb[cno]);
2492 
2493 			if (olen == nlen) {
2494 				nlen = 0;
2495 				break;
2496 			}
2497 			if (olen < nlen) {
2498 				++copydown;
2499 				nlen -= olen;
2500 			} else {
2501 				BINC_RET(sp,
2502 				    tp->lb, tp->lb_len, tp->len + olen);
2503 				chlen = olen - nlen;
2504 				memmove(tp->lb + cno + 1 + chlen,
2505 				    tp->lb + cno + 1, tp->owrite + tp->insert);
2506 
2507 				tp->len += chlen;
2508 				tp->owrite += chlen;
2509 				if (tp->lb[cno] == '\t')
2510 					for (p = tp->lb + cno + 1; chlen--;)
2511 						*p++ = ' ';
2512 				else
2513 					for (kp =
2514 					    KEY_NAME(sp, tp->lb[cno]) + nlen,
2515 					    p = tp->lb + cno + 1; chlen--;)
2516 						*p++ = *kp++;
2517 				nlen = 0;
2518 				break;
2519 			}
2520 		}
2521 
2522 		/*
2523 		 * If had to erase several characters, we adjust the total
2524 		 * count, and if there are any characters left, shift them
2525 		 * into position.
2526 		 */
2527 		if (copydown != 0 && (tp->len -= copydown) != 0)
2528 			memmove(tp->lb + cno, tp->lb + cno + copydown,
2529 			    tp->owrite + tp->insert + copydown);
2530 
2531 		/* If we had enough overwrite characters, we're done. */
2532 		if (nlen == 0) {
2533 			tp->lb[tp->cno++] = *chp;
2534 			return (0);
2535 		}
2536 	}
2537 
2538 	/* Check to see if the character fits into the input buffer. */
2539 	BINC_RET(sp, tp->lb, tp->lb_len, tp->len + 1);
2540 
2541 	++tp->len;
2542 	if (tp->insert) {			/* Insert a character. */
2543 		if (tp->insert == 1)
2544 			tp->lb[tp->cno + 1] = tp->lb[tp->cno];
2545 		else
2546 			memmove(tp->lb + tp->cno + 1,
2547 			    tp->lb + tp->cno, tp->owrite + tp->insert);
2548 	}
2549 	tp->lb[tp->cno++] = *chp;
2550 	return (0);
2551 }
2552 
2553 /*
2554  * txt_isrch --
2555  *	Do an incremental search.
2556  */
2557 static int
2558 txt_isrch(sp, vp, tp, is_flagsp)
2559 	SCR *sp;
2560 	VICMD *vp;
2561 	TEXT *tp;
2562 	u_int8_t *is_flagsp;
2563 {
2564 	MARK start;
2565 	recno_t lno;
2566 	u_int sf;
2567 
2568 	/* If it's a one-line screen, we don't do incrementals. */
2569 	if (IS_ONELINE(sp)) {
2570 		FL_CLR(*is_flagsp, IS_RUNNING);
2571 		return (0);
2572 	}
2573 
2574 	/*
2575 	 * If the user erases back to the beginning of the buffer, there's
2576 	 * nothing to search for.  Reset the cursor to the starting point.
2577 	 */
2578 	if (tp->cno <= 1) {
2579 		vp->m_final = vp->m_start;
2580 		return (0);
2581 	}
2582 
2583 	/*
2584 	 * If it's an RE quote character, and not quoted, ignore it until
2585 	 * we get another character.
2586 	 */
2587 	if (tp->lb[tp->cno - 1] == '\\' &&
2588 	    (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\'))
2589 		return (0);
2590 
2591 	/*
2592 	 * If it's a magic shell character, and not quoted, reset the cursor
2593 	 * to the starting point.
2594 	 */
2595 	if (strchr(O_STR(sp, O_SHELLMETA), tp->lb[tp->cno - 1]) != NULL &&
2596 	    (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\'))
2597 		vp->m_final = vp->m_start;
2598 
2599 	/*
2600 	 * If we see the search pattern termination character, then quit doing
2601 	 * an incremental search.  There may be more, e.g., ":/foo/;/bar/",
2602 	 * and we can't handle that incrementally.  Also, reset the cursor to
2603 	 * the original location, the ex search routines don't know anything
2604 	 * about incremental searches.
2605 	 */
2606 	if (tp->lb[0] == tp->lb[tp->cno - 1] &&
2607 	    (tp->cno == 2 || tp->lb[tp->cno - 2] != '\\')) {
2608 		vp->m_final = vp->m_start;
2609 		FL_CLR(*is_flagsp, IS_RUNNING);
2610 		return (0);
2611 	}
2612 
2613 	/*
2614 	 * Remember the input line and discard the special input map,
2615 	 * but don't overwrite the input line on the screen.
2616 	 */
2617 	lno = tp->lno;
2618 	F_SET(VIP(sp), VIP_S_MODELINE);
2619 	F_CLR(sp, SC_TINPUT | SC_TINPUT_INFO);
2620 	if (txt_map_end(sp))
2621 		return (1);
2622 
2623 	/*
2624 	 * Specify a starting point and search.  If we find a match, move to
2625 	 * it and refresh the screen.  If we didn't find the match, then we
2626 	 * beep the screen.  When searching from the original cursor position,
2627 	 * we have to move the cursor, otherwise, we don't want to move the
2628 	 * cursor in case the text at the current position continues to match.
2629 	 */
2630 	if (FL_ISSET(*is_flagsp, IS_RESTART)) {
2631 		start = vp->m_start;
2632 		sf = SEARCH_SET;
2633 	} else {
2634 		start = vp->m_final;
2635 		sf = SEARCH_INCR | SEARCH_SET;
2636 	}
2637 
2638 	if (tp->lb[0] == '/' ?
2639 	    !f_search(sp,
2640 	    &start, &vp->m_final, tp->lb + 1, tp->cno - 1, NULL, sf) :
2641 	    !b_search(sp,
2642 	    &start, &vp->m_final, tp->lb + 1, tp->cno - 1, NULL, sf)) {
2643 		sp->lno = vp->m_final.lno;
2644 		sp->cno = vp->m_final.cno;
2645 		FL_CLR(*is_flagsp, IS_RESTART);
2646 
2647 		if (!KEYS_WAITING(sp) && vs_refresh(sp, 0))
2648 			return (1);
2649 	} else
2650 		FL_SET(*is_flagsp, IS_RESTART);
2651 
2652 	/* Reinstantiate the special input map. */
2653 	if (txt_map_init(sp))
2654 		return (1);
2655 	F_CLR(VIP(sp), VIP_S_MODELINE);
2656 	F_SET(sp, SC_TINPUT | SC_TINPUT_INFO);
2657 
2658 	/* Reset the line number of the input line. */
2659 	tp->lno = TMAP[0].lno;
2660 
2661 	/*
2662 	 * If the colon command-line moved, i.e. the screen scrolled,
2663 	 * refresh the input line.
2664 	 *
2665 	 * XXX
2666 	 * We shouldn't be calling vs_line, here -- we need dirty bits
2667 	 * on entries in the SMAP array.
2668 	 */
2669 	if (lno != TMAP[0].lno) {
2670 		if (vs_line(sp, &TMAP[0], NULL, NULL))
2671 			return (1);
2672 		(void)sp->gp->scr_refresh(sp, 0);
2673 	}
2674 	return (0);
2675 }
2676 
2677 /*
2678  * txt_resolve --
2679  *	Resolve the input text chain into the file.
2680  */
2681 static int
2682 txt_resolve(sp, tiqh, flags)
2683 	SCR *sp;
2684 	TEXTH *tiqh;
2685 	u_int32_t flags;
2686 {
2687 	VI_PRIVATE *vip;
2688 	TEXT *tp;
2689 	recno_t lno;
2690 	int changed;
2691 
2692 	/*
2693 	 * The first line replaces a current line, and all subsequent lines
2694 	 * are appended into the file.  Resolve autoindented characters for
2695 	 * each line before committing it.  If the latter causes the line to
2696 	 * change, we have to redisplay it, otherwise the information cached
2697 	 * about the line will be wrong.
2698 	 */
2699 	vip = VIP(sp);
2700 	tp = tiqh->cqh_first;
2701 
2702 	if (LF_ISSET(TXT_AUTOINDENT))
2703 		txt_ai_resolve(sp, tp, &changed);
2704 	else
2705 		changed = 0;
2706 	if (db_set(sp, tp->lno, tp->lb, tp->len) ||
2707 	    changed && vs_change(sp, tp->lno, LINE_RESET))
2708 		return (1);
2709 
2710 	for (lno = tp->lno; (tp = tp->q.cqe_next) != (void *)&sp->tiq; ++lno) {
2711 		if (LF_ISSET(TXT_AUTOINDENT))
2712 			txt_ai_resolve(sp, tp, &changed);
2713 		else
2714 			changed = 0;
2715 		if (db_append(sp, 0, lno, tp->lb, tp->len) ||
2716 		    changed && vs_change(sp, tp->lno, LINE_RESET))
2717 			return (1);
2718 	}
2719 
2720 	/*
2721 	 * Clear the input flag, the look-aside buffer is no longer valid.
2722 	 * Has to be done as part of text resolution, or upon return we'll
2723 	 * be looking at incorrect data.
2724 	 */
2725 	F_CLR(sp, SC_TINPUT);
2726 
2727 	return (0);
2728 }
2729 
2730 /*
2731  * txt_showmatch --
2732  *	Show a character match.
2733  *
2734  * !!!
2735  * Historic vi tried to display matches even in the :colon command line.
2736  * I think not.
2737  */
2738 static int
2739 txt_showmatch(sp, tp)
2740 	SCR *sp;
2741 	TEXT *tp;
2742 {
2743 	GS *gp;
2744 	VCS cs;
2745 	MARK m;
2746 	int cnt, endc, startc;
2747 
2748 	gp = sp->gp;
2749 
2750 	/*
2751 	 * Do a refresh first, in case we haven't done one in awhile,
2752 	 * so the user can see what we're complaining about.
2753 	 */
2754 	UPDATE_POSITION(sp, tp);
2755 	if (vs_refresh(sp, 1))
2756 		return (1);
2757 
2758 	/*
2759 	 * We don't display the match if it's not on the screen.  Find
2760 	 * out what the first character on the screen is.
2761 	 */
2762 	if (vs_sm_position(sp, &m, 0, P_TOP))
2763 		return (1);
2764 
2765 	/* Initialize the getc() interface. */
2766 	cs.cs_lno = tp->lno;
2767 	cs.cs_cno = tp->cno - 1;
2768 	if (cs_init(sp, &cs))
2769 		return (1);
2770 	startc = (endc = cs.cs_ch)  == ')' ? '(' : '{';
2771 
2772 	/* Search for the match. */
2773 	for (cnt = 1;;) {
2774 		if (cs_prev(sp, &cs))
2775 			return (1);
2776 		if (cs.cs_flags != 0) {
2777 			if (cs.cs_flags == CS_EOF || cs.cs_flags == CS_SOF) {
2778 				msgq(sp, M_BERR,
2779 				    "Unmatched %s", KEY_NAME(sp, endc));
2780 				return (0);
2781 			}
2782 			continue;
2783 		}
2784 		if (cs.cs_ch == endc)
2785 			++cnt;
2786 		else if (cs.cs_ch == startc && --cnt == 0)
2787 			break;
2788 	}
2789 
2790 	/* If the match is on the screen, move to it. */
2791 	if (cs.cs_lno < m.lno || cs.cs_lno == m.lno && cs.cs_cno < m.cno)
2792 		return (0);
2793 	sp->lno = cs.cs_lno;
2794 	sp->cno = cs.cs_cno;
2795 	if (vs_refresh(sp, 1))
2796 		return (1);
2797 
2798 	/* Wait for timeout or character arrival. */
2799 	return (v_event_get(sp,
2800 	    NULL, O_VAL(sp, O_MATCHTIME) * 100, EC_TIMEOUT));
2801 }
2802 
2803 /*
2804  * txt_margin --
2805  *	Handle margin wrap.
2806  */
2807 static int
2808 txt_margin(sp, tp, wmtp, didbreak, flags)
2809 	SCR *sp;
2810 	TEXT *tp, *wmtp;
2811 	int *didbreak;
2812 	u_int32_t flags;
2813 {
2814 	VI_PRIVATE *vip;
2815 	size_t len, off;
2816 	char *p, *wp;
2817 
2818 	/* Find the nearest previous blank. */
2819 	for (off = tp->cno - 1, p = tp->lb + off, len = 0;; --off, --p, ++len) {
2820 		if (isblank(*p)) {
2821 			wp = p + 1;
2822 			break;
2823 		}
2824 
2825 		/*
2826 		 * If reach the start of the line, there's nowhere to break.
2827 		 *
2828 		 * !!!
2829 		 * Historic vi belled each time a character was entered after
2830 		 * crossing the margin until a space was entered which could
2831 		 * be used to break the line.  I don't as it tends to wake the
2832 		 * cats.
2833 		 */
2834 		if (off == tp->ai || off == tp->offset) {
2835 			*didbreak = 0;
2836 			return (0);
2837 		}
2838 	}
2839 
2840 	/*
2841 	 * Store saved information about the rest of the line in the
2842 	 * wrapmargin TEXT structure.
2843 	 *
2844 	 * !!!
2845 	 * The offset field holds the length of the current characters
2846 	 * that the user entered, but which are getting split to the new
2847 	 * line -- it's going to be used to set the cursor value when we
2848 	 * move to the new line.
2849 	 */
2850 	vip = VIP(sp);
2851 	wmtp->lb = p + 1;
2852 	wmtp->offset = len;
2853 	wmtp->insert = LF_ISSET(TXT_APPENDEOL) ?  tp->insert - 1 : tp->insert;
2854 	wmtp->owrite = tp->owrite;
2855 
2856 	/* Correct current bookkeeping information. */
2857 	tp->cno -= len;
2858 	if (LF_ISSET(TXT_APPENDEOL)) {
2859 		tp->len -= len + tp->owrite + (tp->insert - 1);
2860 		tp->insert = 1;
2861 	} else {
2862 		tp->len -= len + tp->owrite + tp->insert;
2863 		tp->insert = 0;
2864 	}
2865 	tp->owrite = 0;
2866 
2867 	/*
2868 	 * !!!
2869 	 * Delete any trailing whitespace from the current line.
2870 	 */
2871 	for (;; --p, --off) {
2872 		if (!isblank(*p))
2873 			break;
2874 		--tp->cno;
2875 		--tp->len;
2876 		if (off == tp->ai || off == tp->offset)
2877 			break;
2878 	}
2879 	*didbreak = 1;
2880 	return (0);
2881 }
2882 
2883 /*
2884  * txt_Rresolve --
2885  *	Resolve the input line for the 'R' command.
2886  */
2887 static void
2888 txt_Rresolve(sp, tiqh, tp, orig_len)
2889 	SCR *sp;
2890 	TEXTH *tiqh;
2891 	TEXT *tp;
2892 	const size_t orig_len;
2893 {
2894 	TEXT *ttp;
2895 	size_t input_len, retain;
2896 	char *p;
2897 
2898 	/*
2899 	 * Check to make sure that the cursor hasn't moved beyond
2900 	 * the end of the line.
2901 	 */
2902 	if (tp->owrite == 0)
2903 		return;
2904 
2905 	/*
2906 	 * Calculate how many characters the user has entered,
2907 	 * plus the blanks erased by <carriage-return>/<newline>s.
2908 	 */
2909 	for (ttp = tiqh->cqh_first, input_len = 0;;) {
2910 		input_len += ttp == tp ? tp->cno : ttp->len + ttp->R_erase;
2911 		if ((ttp = ttp->q.cqe_next) == (void *)&sp->tiq)
2912 			break;
2913 	}
2914 
2915 	/*
2916 	 * If the user has entered less characters than the original line
2917 	 * was long, restore any overwriteable characters to the original
2918 	 * characters.  These characters are entered as "insert characters",
2919 	 * because they're after the cursor and we don't want to lose them.
2920 	 * (This is okay because the R command has no insert characters.)
2921 	 * We set owrite to 0 so that the insert characters don't get copied
2922 	 * to somewhere else, which means that the line and the length have
2923 	 * to be adjusted here as well.
2924 	 *
2925 	 * We have to retrieve the original line because the original pinned
2926 	 * page has long since been discarded.  If it doesn't exist, that's
2927 	 * okay, the user just extended the file.
2928 	 */
2929 	if (input_len < orig_len) {
2930 		retain = MIN(tp->owrite, orig_len - input_len);
2931 		if (db_get(sp,
2932 		    tiqh->cqh_first->lno, DBG_FATAL | DBG_NOCACHE, &p, NULL))
2933 			return;
2934 		memcpy(tp->lb + tp->cno, p + input_len, retain);
2935 		tp->len -= tp->owrite - retain;
2936 		tp->owrite = 0;
2937 		tp->insert += retain;
2938 	}
2939 }
2940 
2941 /*
2942  * txt_nomorech --
2943  *	No more characters message.
2944  */
2945 static void
2946 txt_nomorech(sp)
2947 	SCR *sp;
2948 {
2949 	msgq(sp, M_BERR, "194|No more characters to erase");
2950 }
2951