xref: /freebsd/contrib/tcsh/sh.lex.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /* $Header: /p/tcsh/cvsroot/tcsh/sh.lex.c,v 3.91 2016/08/01 16:21:09 christos Exp $ */
2 /*
3  * sh.lex.c: Lexical analysis into tokens
4  */
5 /*-
6  * Copyright (c) 1980, 1991 The Regents of the University of California.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 #include "sh.h"
34 
35 RCSID("$tcsh: sh.lex.c,v 3.91 2016/08/01 16:21:09 christos Exp $")
36 
37 #include "ed.h"
38 
39 #include <assert.h>
40 /* #define DEBUG_INP */
41 /* #define DEBUG_SEEK */
42 
43 /*
44  * C shell
45  */
46 
47 #define FLAG_G	1
48 #define FLAG_A	2
49 /*
50  * These lexical routines read input and form lists of words.
51  * There is some involved processing here, because of the complications
52  * of input buffering, and especially because of history substitution.
53  */
54 static	Char		*word		(int);
55 static	eChar	 	 getC1		(int);
56 static	void	 	 getdol		(void);
57 static	void	 	 getexcl	(Char);
58 static	struct Hist 	*findev		(Char *, int);
59 static	void	 	 setexclp	(Char *);
60 static	eChar	 	 bgetc		(void);
61 static	void		 balloc		(int);
62 static	void	 	 bfree		(void);
63 static	struct wordent	*gethent	(Char);
64 static	int	 	 matchs		(const Char *, const Char *);
65 static	int	 	 getsel		(int *, int *, int);
66 static	struct wordent	*getsub		(struct wordent *);
67 static	Char 		*subword	(Char *, Char, int *, size_t *);
68 static	struct wordent	*dosub		(Char, struct wordent *, int);
69 
70 /*
71  * Peekc is a peek character for getC, peekread for readc.
72  * There is a subtlety here in many places... history routines
73  * will read ahead and then insert stuff into the input stream.
74  * If they push back a character then they must push it behind
75  * the text substituted by the history substitution.  On the other
76  * hand in several places we need 2 peek characters.  To make this
77  * all work, the history routines read with getC, and make use both
78  * of ungetC and unreadc.  The key observation is that the state
79  * of getC at the call of a history reference is such that calls
80  * to getC from the history routines will always yield calls of
81  * readc, unless this peeking is involved.  That is to say that during
82  * getexcl the variables lap, exclp, and exclnxt are all zero.
83  *
84  * Getdol invokes history substitution, hence the extra peek, peekd,
85  * which it can ungetD to be before history substitutions.
86  */
87 static Char peekc = 0, peekd = 0;
88 static Char peekread = 0;
89 
90 /* (Tail of) current word from ! subst */
91 static Char *exclp = NULL;
92 
93 /* The rest of the ! subst words */
94 static struct wordent *exclnxt = NULL;
95 
96 /* Count of remaining words in ! subst */
97 static int exclc = 0;
98 
99 /* "Globp" for alias resubstitution */
100 int aret = TCSH_F_SEEK;
101 
102 /*
103  * Labuf implements a general buffer for lookahead during lexical operations.
104  * Text which is to be placed in the input stream can be stuck here.
105  * We stick parsed ahead $ constructs during initial input,
106  * process id's from `$$', and modified variable values (from qualifiers
107  * during expansion in sh.dol.c) here.
108  */
109 struct Strbuf labuf; /* = Strbuf_INIT; */
110 
111 /*
112  * Lex returns to its caller not only a wordlist (as a "var" parameter)
113  * but also whether a history substitution occurred.  This is used in
114  * the main (process) routine to determine whether to echo, and also
115  * when called by the alias routine to determine whether to keep the
116  * argument list.
117  */
118 static int hadhist = 0;
119 
120 /*
121  * Avoid alias expansion recursion via \!#
122  */
123 int     hleft;
124 
125 struct Strbuf histline; /* = Strbuf_INIT; last line input */
126 
127 int    histvalid = 0;		/* is histline valid */
128 
129 static Char getCtmp;
130 
131 #define getC(f)		(((getCtmp = peekc) != '\0') ? (peekc = 0, (eChar)getCtmp) : getC1(f))
132 #define	ungetC(c)	peekc = (Char) c
133 #define	ungetD(c)	peekd = (Char) c
134 
135 /* Use Htime to store timestamps picked up from history file for enthist()
136  * if reading saved history (sg)
137  */
138 time_t Htime = (time_t)0;
139 static time_t a2time_t (Char *);
140 
141 /*
142  * special parsing rules apply for source -h
143  */
144 extern int enterhist;
145 
146 int
147 lex(struct wordent *hp)
148 {
149     struct wordent *wdp;
150     eChar    c;
151     int     parsehtime = enterhist;
152 
153     histvalid = 0;
154     histline.len = 0;
155 
156     btell(&lineloc);
157     hp->next = hp->prev = hp;
158     hp->word = STRNULL;
159     hadhist = 0;
160     do
161 	c = readc(0);
162     while (c == ' ' || c == '\t');
163     if (c == (eChar)HISTSUB && intty)
164 	/* ^lef^rit	from tty is short !:s^lef^rit */
165 	getexcl(c);
166     else
167 	unreadc(c);
168     cleanup_push(hp, lex_cleanup);
169     wdp = hp;
170     /*
171      * The following loop is written so that the links needed by freelex will
172      * be ready and rarin to go even if it is interrupted.
173      */
174     do {
175 	struct wordent *new;
176 
177 	new = xmalloc(sizeof(*new));
178 	new->word = NULL;
179 	new->prev = wdp;
180 	new->next = hp;
181 	wdp->next = new;
182 	hp->prev = new;
183 	wdp = new;
184 	wdp->word = word(parsehtime);
185 	parsehtime = 0;
186     } while (wdp->word[0] != '\n');
187     cleanup_ignore(hp);
188     cleanup_until(hp);
189     Strbuf_terminate(&histline);
190     if (histline.len != 0 && histline.s[histline.len - 1] == '\n')
191 	histline.s[histline.len - 1] = '\0';
192     histvalid = 1;
193 
194     return (hadhist);
195 }
196 
197 static time_t
198 a2time_t(Char *wordx)
199 {
200     /* Attempt to distinguish timestamps from other possible entries.
201      * Format: "+NNNNNNNNNN" (10 digits, left padded with ascii '0') */
202 
203     time_t ret;
204     Char *s;
205     int ct;
206 
207     if (!wordx || *(s = wordx) != '+')
208 	return (time_t)0;
209 
210     for (++s, ret = 0, ct = 0; *s; ++s, ++ct) {
211 	if (!isdigit((unsigned char)*s))
212 	    return (time_t)0;
213 	ret = ret * 10 + (time_t)((unsigned char)*s - '0');
214     }
215 
216     if (ct != 10)
217 	return (time_t)0;
218 
219     return ret;
220 }
221 
222 void
223 prlex(struct wordent *sp0)
224 {
225     struct wordent *sp = sp0->next;
226 
227     for (;;) {
228 	xprintf("%S", sp->word);
229 	sp = sp->next;
230 	if (sp == sp0)
231 	    break;
232 	if (sp->word[0] != '\n')
233 	    xputchar(' ');
234     }
235 }
236 
237 void
238 copylex(struct wordent *hp, struct wordent *fp)
239 {
240     struct wordent *wdp;
241 
242     wdp = hp;
243     fp = fp->next;
244     do {
245 	struct wordent *new;
246 
247 	new = xmalloc(sizeof(*new));
248 	new->word = NULL;
249 	new->prev = wdp;
250 	new->next = hp;
251 	wdp->next = new;
252 	hp->prev = new;
253 	wdp = new;
254 	wdp->word = Strsave(fp->word);
255 	fp = fp->next;
256     } while (wdp->word[0] != '\n');
257 }
258 
259 void
260 initlex(struct wordent *vp)
261 {
262 	vp->word = STRNULL;
263 	vp->prev = vp;
264 	vp->next = vp;
265 }
266 
267 void
268 freelex(struct wordent *vp)
269 {
270     struct wordent *fp;
271 
272     while (vp->next != vp) {
273 	fp = vp->next;
274 	vp->next = fp->next;
275 	xfree(fp->word);
276 	xfree(fp);
277     }
278     vp->prev = vp;
279 }
280 
281 void
282 lex_cleanup(void *xvp)
283 {
284     struct wordent *vp;
285 
286     vp = xvp;
287     freelex(vp);
288 }
289 
290 static Char *
291 word(int parsehtime)
292 {
293     eChar c, c1;
294     struct Strbuf wbuf = Strbuf_INIT;
295     Char    hbuf[12];
296     int	    h;
297     int dolflg;
298 
299     cleanup_push(&wbuf, Strbuf_cleanup);
300 loop:
301     while ((c = getC(DOALL)) == ' ' || c == '\t')
302 	continue;
303     if (cmap(c, _META | _ESC))
304 	switch (c) {
305 	case '&':
306 	case '|':
307 	case '<':
308 	case '>':
309 	    Strbuf_append1(&wbuf, c);
310 	    c1 = getC(DOALL);
311 	    if (c1 == c)
312 		Strbuf_append1(&wbuf, c1);
313 	    else
314 		ungetC(c1);
315 	    goto ret;
316 
317 	case '#':
318 	    if (intty || (enterhist && !parsehtime))
319 		break;
320 	    c = 0;
321 	    h = 0;
322 	    do {
323 		c1 = c;
324 		c = getC(0);
325 		if (h < 11 && parsehtime)
326 		    hbuf[h++] = c;
327 	    } while (c != '\n');
328 	    if (parsehtime) {
329 		hbuf[11] = '\0';
330 		Htime = a2time_t(hbuf);
331 	    }
332 	    if (c1 == '\\')
333 		goto loop;
334 	    /*FALLTHROUGH*/
335 
336 	case ';':
337 	case '(':
338 	case ')':
339 	case '\n':
340 	    Strbuf_append1(&wbuf, c);
341 	    goto ret;
342 
343 	case '\\':
344 	    c = getC(0);
345 	    if (c == '\n') {
346 		if (onelflg == 1)
347 		    onelflg = 2;
348 		goto loop;
349 	    }
350 	    if (c != (eChar)HIST)
351 		Strbuf_append1(&wbuf, '\\');
352 	    c |= QUOTE;
353 	default:
354 	    break;
355 	}
356     c1 = 0;
357     dolflg = DOALL;
358     for (;;) {
359 	if (c1) {
360 	    if (c == c1) {
361 		c1 = 0;
362 		dolflg = DOALL;
363 	    }
364 	    else if (c == '\\') {
365 		c = getC(0);
366 /*
367  * PWP: this is dumb, but how all of the other shells work.  If \ quotes
368  * a character OUTSIDE of a set of ''s, why shouldn't it quote EVERY
369  * following character INSIDE a set of ''s.
370  *
371  * Actually, all I really want to be able to say is 'foo\'bar' --> foo'bar
372  */
373 		if (c == (eChar)HIST)
374 		    c |= QUOTE;
375 		else {
376 		    if (bslash_quote &&
377 			((c == '\'') || (c == '"') ||
378 			 (c == '\\') || (c == '$'))) {
379 			c |= QUOTE;
380 		    }
381 		    else {
382 			if (c == '\n')
383 			    /*
384 			     * if (c1 == '`') c = ' '; else
385 			     */
386 			    c |= QUOTE;
387 			ungetC(c);
388 			c = '\\' | QUOTE;
389 		    }
390 		}
391 	    }
392 	    else if (c == '\n') {
393 		seterror(ERR_UNMATCHED, c1);
394 		ungetC(c);
395 		break;
396 	    }
397 	}
398 	else if (cmap(c, _META | _QF | _QB | _ESC)) {
399 	    if (c == '\\') {
400 		c = getC(0);
401 		if (c == '\n') {
402 		    if (onelflg == 1)
403 			onelflg = 2;
404 		    break;
405 		}
406 		if (c != (eChar)HIST)
407 		    Strbuf_append1(&wbuf, '\\');
408 		c |= QUOTE;
409 	    }
410 	    else if (cmap(c, _QF | _QB)) {	/* '"` */
411 		c1 = c;
412 		dolflg = c == '"' ? DOALL : DOEXCL;
413 	    }
414 	    else if (c != '#' || (!intty && !enterhist)) {
415 		ungetC(c);
416 		break;
417 	    }
418 	}
419 	Strbuf_append1(&wbuf, c);
420 	c = getC(dolflg);
421     }
422 ret:
423     cleanup_ignore(&wbuf);
424     cleanup_until(&wbuf);
425     return Strbuf_finish(&wbuf);
426 }
427 
428 static eChar
429 getC1(int flag)
430 {
431     eChar c;
432 
433     for (;;) {
434 	if ((c = peekc) != 0) {
435 	    peekc = 0;
436 	    return (c);
437 	}
438 	if (lap < labuf.len) {
439 	    c = labuf.s[lap++];
440 	    if (cmap(c, _META | _QF | _QB))
441 		c |= QUOTE;
442 	    return (c);
443 	}
444 	if ((c = peekd) != 0) {
445 	    peekd = 0;
446 	    return (c);
447 	}
448 	if (exclp) {
449 	    if ((c = *exclp++) != 0)
450 		return (c);
451 	    if (exclnxt && --exclc >= 0) {
452 		exclnxt = exclnxt->next;
453 		setexclp(exclnxt->word);
454 		return (' ');
455 	    }
456 	    exclp = 0;
457 	    exclnxt = 0;
458 	    /* this will throw away the dummy history entries */
459 	    savehist(NULL, 0);
460 
461 	}
462 	if (exclnxt) {
463 	    exclnxt = exclnxt->next;
464 	    if (--exclc < 0)
465 		exclnxt = 0;
466 	    else
467 		setexclp(exclnxt->word);
468 	    continue;
469 	}
470 	c = readc(1);
471 
472 	/* Catch EOF in the middle of a line.  (An EOF at the beginning of
473 	 * a line would have been processed by the readc(0) in lex().) */
474 	if (c == CHAR_ERR)
475 	    c = '\n';
476 
477 	if (c == '$' && (flag & DODOL)) {
478 	    getdol();
479 	    continue;
480 	}
481 	if (c == (eChar)HIST && (flag & DOEXCL)) {
482 	    getexcl(0);
483 	    continue;
484 	}
485 	break;
486     }
487     return (c);
488 }
489 
490 static void
491 getdol(void)
492 {
493     struct Strbuf name = Strbuf_INIT;
494     eChar c;
495     eChar   sc;
496     int    special = 0;
497 
498     c = sc = getC(DOEXCL);
499     if (any("\t \n", c)) {
500 	ungetD(c);
501 	ungetC('$' | QUOTE);
502 	return;
503     }
504     cleanup_push(&name, Strbuf_cleanup);
505     Strbuf_append1(&name, '$');
506     if (c == '{')
507 	Strbuf_append1(&name, c), c = getC(DOEXCL);
508     if (c == '#' || c == '?' || c == '%')
509 	special++, Strbuf_append1(&name, c), c = getC(DOEXCL);
510     Strbuf_append1(&name, c);
511     switch (c) {
512 
513     case '<':
514     case '$':
515     case '!':
516 	if (special)
517 	    seterror(ERR_SPDOLLT);
518 	goto end;
519 
520     case '\n':
521 	ungetD(c);
522 	name.len--;
523 	if (!special)
524 	    seterror(ERR_NEWLINE);
525 	goto end;
526 
527     case '*':
528 	if (special)
529 	    seterror(ERR_SPSTAR);
530 	goto end;
531 
532     default:
533 	if (Isdigit(c)) {
534 #ifdef notdef
535 	    /* let $?0 pass for now */
536 	    if (special) {
537 		seterror(ERR_DIGIT);
538 		goto end;
539 	    }
540 #endif
541 	    while ((c = getC(DOEXCL)) != 0) {
542 		if (!Isdigit(c))
543 		    break;
544 		Strbuf_append1(&name, c);
545 	    }
546 	}
547 	else if (letter(c)) {
548 	    while ((c = getC(DOEXCL)) != 0) {
549 		/* Bugfix for ${v123x} from Chris Torek, DAS DEC-90. */
550 		if (!letter(c) && !Isdigit(c))
551 		    break;
552 		Strbuf_append1(&name, c);
553 	    }
554 	}
555 	else {
556 	    if (!special)
557 		seterror(ERR_VARILL);
558 	    else {
559 		ungetD(c);
560 		name.len--;
561 	    }
562 	    goto end;
563 	}
564 	break;
565     }
566     if (c == '[') {
567 	Strbuf_append1(&name, c);
568 	do {
569 	    /*
570 	     * Michael Greim: Allow $ expansion to take place in selector
571 	     * expressions. (limits the number of characters returned)
572 	     */
573 	    c = getC(DOEXCL | DODOL);
574 	    if (c == '\n') {
575 		ungetD(c);
576 		name.len--;
577 		seterror(ERR_NLINDEX);
578 		goto end;
579 	    }
580 	    Strbuf_append1(&name, c);
581 	} while (c != ']');
582 	c = getC(DOEXCL);
583     }
584     if (c == ':') {
585 	/*
586 	 * if the :g modifier is followed by a newline, then error right away!
587 	 * -strike
588 	 */
589 
590 	int     gmodflag = 0, amodflag = 0;
591 
592 	do {
593 	    Strbuf_append1(&name, c), c = getC(DOEXCL);
594 	    if (c == 'g' || c == 'a') {
595 		if (c == 'g')
596 		    gmodflag++;
597 		else
598 		    amodflag++;
599 		Strbuf_append1(&name, c); c = getC(DOEXCL);
600 	    }
601 	    if ((c == 'g' && !gmodflag) || (c == 'a' && !amodflag)) {
602 		if (c == 'g')
603 		    gmodflag++;
604 		else
605 		    amodflag++;
606 		Strbuf_append1(&name, c); c = getC(DOEXCL);
607 	    }
608 	    Strbuf_append1(&name, c);
609 	    /* scan s// [eichin:19910926.0512EST] */
610 	    if (c == 's') {
611 		int delimcnt = 2;
612 		eChar delim = getC(0);
613 
614 		Strbuf_append1(&name, delim);
615 		if (!delim || letter(delim)
616 		    || Isdigit(delim) || any(" \t\n", delim)) {
617 		    seterror(ERR_BADSUBST);
618 		    break;
619 		}
620 		while ((c = getC(0)) != CHAR_ERR) {
621 		    Strbuf_append1(&name, c);
622 		    if(c == delim) delimcnt--;
623 		    if(!delimcnt) break;
624 		}
625 		if(delimcnt) {
626 		    seterror(ERR_BADSUBST);
627 		    break;
628 		}
629 		c = 's';
630 	    }
631 	    if (!any("htrqxesul", c)) {
632 		if ((amodflag || gmodflag) && c == '\n')
633 		    stderror(ERR_VARSYN);	/* strike */
634 		seterror(ERR_BADMOD, c);
635 		goto end;
636 	    }
637 	}
638 	while ((c = getC(DOEXCL)) == ':');
639 	ungetD(c);
640     }
641     else
642 	ungetD(c);
643     if (sc == '{') {
644 	c = getC(DOEXCL);
645 	if (c != '}') {
646 	    ungetD(c);
647 	    seterror(ERR_MISSING, '}');
648 	    goto end;
649 	}
650 	Strbuf_append1(&name, c);
651     }
652  end:
653     cleanup_ignore(&name);
654     cleanup_until(&name);
655     addla(Strbuf_finish(&name));
656 }
657 
658 /* xfree()'s its argument */
659 void
660 addla(Char *cp)
661 {
662     static struct Strbuf buf; /* = Strbuf_INIT; */
663 
664     buf.len = 0;
665     Strbuf_appendn(&buf, labuf.s + lap, labuf.len - lap);
666     labuf.len = 0;
667     Strbuf_append(&labuf, cp);
668     Strbuf_terminate(&labuf);
669     Strbuf_appendn(&labuf, buf.s, buf.len);
670     xfree(cp);
671     lap = 0;
672 }
673 
674 /* left-hand side of last :s or search string of last ?event? */
675 static struct Strbuf lhsb; /* = Strbuf_INIT; */
676 static struct Strbuf slhs; /* = Strbuf_INIT; left-hand side of last :s */
677 static struct Strbuf rhsb; /* = Strbuf_INIT; right-hand side of last :s */
678 static int quesarg;
679 
680 static void
681 getexcl(Char sc)
682 {
683     struct wordent *hp, *ip;
684     int     left, right, dol;
685     eChar c;
686 
687     if (sc == 0) {
688 	c = getC(0);
689 	if (c == '{')
690 	    sc = (Char) c;
691 	else
692 	    ungetC(c);
693     }
694     quesarg = -1;
695 
696     lastev = eventno;
697     hp = gethent(sc);
698     if (hp == 0)
699 	return;
700     hadhist = 1;
701     dol = 0;
702     if (hp == alhistp)
703 	for (ip = hp->next->next; ip != alhistt; ip = ip->next)
704 	    dol++;
705     else
706 	for (ip = hp->next->next; ip != hp->prev; ip = ip->next)
707 	    dol++;
708     left = 0, right = dol;
709     if (sc == HISTSUB && HISTSUB != '\0') {
710 	ungetC('s'), unreadc(HISTSUB), c = ':';
711 	goto subst;
712     }
713     c = getC(0);
714     if (!any(":^$*-%", c))
715 	goto subst;
716     left = right = -1;
717     if (c == ':') {
718 	c = getC(0);
719 	unreadc(c);
720 	if (letter(c) || c == '&') {
721 	    c = ':';
722 	    left = 0, right = dol;
723 	    goto subst;
724 	}
725     }
726     else
727 	ungetC(c);
728     if (!getsel(&left, &right, dol))
729 	return;
730     c = getC(0);
731     if (c == '*')
732 	ungetC(c), c = '-';
733     if (c == '-') {
734 	if (!getsel(&left, &right, dol))
735 	    return;
736 	c = getC(0);
737     }
738 subst:
739     exclc = right - left + 1;
740     while (--left >= 0)
741 	hp = hp->next;
742     if ((sc == HISTSUB && HISTSUB != '\0') || c == ':') {
743 	do {
744 	    hp = getsub(hp);
745 	    c = getC(0);
746 	} while (c == ':');
747     }
748     unreadc(c);
749     if (sc == '{') {
750 	c = getC(0);
751 	if (c != '}')
752 	    seterror(ERR_BADBANG);
753     }
754     exclnxt = hp;
755 }
756 
757 static struct wordent *
758 getsub(struct wordent *en)
759 {
760     eChar   delim;
761     eChar   c;
762     eChar   sc;
763     int global;
764 
765     do {
766 	exclnxt = 0;
767 	global = 0;
768 	sc = c = getC(0);
769 	while (c == 'g' || c == 'a') {
770 	    global |= (c == 'g') ? FLAG_G : FLAG_A;
771 	    sc = c = getC(0);
772 	}
773 
774 	switch (c) {
775 	case 'p':
776 	    justpr++;
777 	    return (en);
778 
779 	case 'x':
780 	case 'q':
781 	    global |= FLAG_G;
782 	    /*FALLTHROUGH*/
783 
784 	case 'h':
785 	case 'r':
786 	case 't':
787 	case 'e':
788 	case 'u':
789 	case 'l':
790 	    break;
791 
792 	case '&':
793 	    if (slhs.len == 0) {
794 		seterror(ERR_NOSUBST);
795 		return (en);
796 	    }
797 	    lhsb.len = 0;
798 	    Strbuf_append(&lhsb, slhs.s);
799 	    Strbuf_terminate(&lhsb);
800 	    break;
801 
802 #ifdef notdef
803 	case '~':
804 	    if (lhsb.len == 0)
805 		goto badlhs;
806 	    break;
807 #endif
808 
809 	case 's':
810 	    delim = getC(0);
811 	    if (letter(delim) || Isdigit(delim) || any(" \t\n", delim)) {
812 		unreadc(delim);
813 		lhsb.len = 0;
814 		seterror(ERR_BADSUBST);
815 		return (en);
816 	    }
817 	    Strbuf_terminate(&lhsb);
818 	    lhsb.len = 0;
819 	    for (;;) {
820 		c = getC(0);
821 		if (c == '\n') {
822 		    unreadc(c);
823 		    break;
824 		}
825 		if (c == delim)
826 		    break;
827 		if (c == '\\') {
828 		    c = getC(0);
829 		    if (c != delim && c != '\\')
830 			Strbuf_append1(&lhsb, '\\');
831 		}
832 		Strbuf_append1(&lhsb, c);
833 	    }
834 	    if (lhsb.len != 0)
835 		Strbuf_terminate(&lhsb);
836 	    else if (lhsb.s[0] == 0) {
837 		seterror(ERR_LHS);
838 		return (en);
839 	    } else
840 		lhsb.len = Strlen(lhsb.s); /* lhsb.s wasn't changed */
841 	    rhsb.len = 0;
842 	    for (;;) {
843 		c = getC(0);
844 		if (c == '\n') {
845 		    unreadc(c);
846 		    break;
847 		}
848 		if (c == delim)
849 		    break;
850 		if (c == '\\') {
851 		    c = getC(0);
852 		    if (c != delim /* && c != '~' */ )
853 			Strbuf_append1(&rhsb,  '\\');
854 		}
855 		Strbuf_append1(&rhsb, c);
856 	    }
857 	    Strbuf_terminate(&rhsb);
858 	    break;
859 
860 	default:
861 	    if (c == '\n')
862 		unreadc(c);
863 	    seterror(ERR_BADBANGMOD, (int)c);
864 	    return (en);
865 	}
866 	slhs.len = 0;
867 	if (lhsb.s != NULL && lhsb.len != 0)
868 	    Strbuf_append(&slhs, lhsb.s);
869 	Strbuf_terminate(&slhs);
870 	if (exclc)
871 	    en = dosub(sc, en, global);
872     }
873     while ((c = getC(0)) == ':');
874     unreadc(c);
875     return (en);
876 }
877 
878 /*
879  *
880  * From Beto Appleton (beto@aixwiz.austin.ibm.com)
881  *
882  * when using history substitution, and the variable
883  * 'history' is set to a value higher than 1000,
884  * the shell might either freeze (hang) or core-dump.
885  * We raise the limit to 50000000
886  */
887 
888 #define HIST_PURGE -50000000
889 static struct wordent *
890 dosub(Char sc, struct wordent *en, int global)
891 {
892     struct wordent lexi;
893     int    didsub = 0, didone = 0;
894     struct wordent *hp = &lexi;
895     struct wordent *wdp;
896     int i = exclc;
897     struct Hist *hst;
898 
899     wdp = hp;
900     while (--i >= 0) {
901 	struct wordent *new = xcalloc(1, sizeof *wdp);
902 
903 	new->word = 0;
904 	new->prev = wdp;
905 	new->next = hp;
906 	wdp->next = new;
907 	wdp = new;
908 	en = en->next;
909 	if (en->word) {
910 	    Char *tword, *otword;
911 
912 	    if ((global & FLAG_G) || didsub == 0) {
913 		size_t pos;
914 
915 		pos = 0;
916 		tword = subword(en->word, sc, &didone, &pos);
917 		if (didone)
918 		    didsub = 1;
919 		if (global & FLAG_A) {
920 		    while (didone && tword != STRNULL) {
921 			otword = tword;
922 			tword = subword(otword, sc, &didone, &pos);
923 			if (Strcmp(tword, otword) == 0) {
924 			    xfree(otword);
925 			    break;
926 			}
927 			else
928 			    xfree(otword);
929 		    }
930 		}
931 	    }
932 	    else
933 		tword = Strsave(en->word);
934 	    wdp->word = tword;
935 	}
936     }
937     if (didsub == 0)
938 	seterror(ERR_MODFAIL);
939     hp->prev = wdp;
940     /*
941      * ANSI mode HP/UX compiler chokes on
942      * return &enthist(HIST_PURGE, &lexi, 0)->Hlex;
943      */
944     hst = enthist(HIST_PURGE, &lexi, 0, 0, -1);
945     return &(hst->Hlex);
946 }
947 
948 /* Return a newly allocated result of one modification of CP using the
949    operation TYPE.  Set ADID to 1 if a modification was performed.
950    If TYPE == 's', perform substitutions only from *START_POS on and set
951    *START_POS to the position of next substitution attempt. */
952 static Char *
953 subword(Char *cp, Char type, int *adid, size_t *start_pos)
954 {
955     Char *wp;
956     const Char *mp, *np;
957 
958     switch (type) {
959 
960     case 'r':
961     case 'e':
962     case 'h':
963     case 't':
964     case 'q':
965     case 'x':
966     case 'u':
967     case 'l':
968 	wp = domod(cp, type);
969 	if (wp == 0) {
970 	    *adid = 0;
971 	    return (Strsave(cp));
972 	}
973 	*adid = 1;
974 	return (wp);
975 
976     default:
977 	for (mp = cp + *start_pos; *mp; mp++) {
978 	    if (matchs(mp, lhsb.s)) {
979 		struct Strbuf wbuf = Strbuf_INIT;
980 
981 		Strbuf_appendn(&wbuf, cp, mp - cp);
982 		for (np = rhsb.s; *np; np++)
983 		    switch (*np) {
984 
985 		    case '\\':
986 			if (np[1] == '&')
987 			    np++;
988 			/* fall into ... */
989 
990 		    default:
991 			Strbuf_append1(&wbuf, *np);
992 			continue;
993 
994 		    case '&':
995 			Strbuf_append(&wbuf, lhsb.s);
996 			continue;
997 		    }
998 		*start_pos = wbuf.len;
999 		Strbuf_append(&wbuf, mp + lhsb.len);
1000 		*adid = 1;
1001 		return Strbuf_finish(&wbuf);
1002 	    }
1003 	}
1004 	*adid = 0;
1005 	return (Strsave(cp));
1006     }
1007 }
1008 
1009 Char   *
1010 domod(Char *cp, Char type)
1011 {
1012     Char *wp, *xp;
1013     int c;
1014 
1015     switch (type) {
1016 
1017     case 'x':
1018     case 'q':
1019 	wp = Strsave(cp);
1020 	for (xp = wp; (c = *xp) != 0; xp++)
1021 	    if ((c != ' ' && c != '\t') || type == 'q')
1022 		*xp |= QUOTE;
1023 	return (wp);
1024 
1025     case 'l':
1026 	wp = NLSChangeCase(cp, 1);
1027 	return wp ? wp : Strsave(cp);
1028 
1029     case 'u':
1030 	wp = NLSChangeCase(cp, 0);
1031 	return wp ? wp : Strsave(cp);
1032 
1033     case 'h':
1034     case 't':
1035 	if (!any(short2str(cp), '/'))
1036 	    return (type == 't' ? Strsave(cp) : 0);
1037 	wp = Strrchr(cp, '/');
1038 	if (type == 'h')
1039 	    xp = Strnsave(cp, wp - cp);
1040 	else
1041 	    xp = Strsave(wp + 1);
1042 	return (xp);
1043 
1044     case 'e':
1045     case 'r':
1046 	wp = Strend(cp);
1047 	for (wp--; wp >= cp && *wp != '/'; wp--)
1048 	    if (*wp == '.') {
1049 		if (type == 'e')
1050 		    xp = Strsave(wp + 1);
1051 		else
1052 		    xp = Strnsave(cp, wp - cp);
1053 		return (xp);
1054 	    }
1055 	return (Strsave(type == 'e' ? STRNULL : cp));
1056     default:
1057 	break;
1058     }
1059     return (0);
1060 }
1061 
1062 static int
1063 matchs(const Char *str, const Char *pat)
1064 {
1065     while (*str && *pat && *str == *pat)
1066 	str++, pat++;
1067     return (*pat == 0);
1068 }
1069 
1070 static int
1071 getsel(int *al, int *ar, int dol)
1072 {
1073     eChar c = getC(0);
1074     int i;
1075     int    first = *al < 0;
1076 
1077     switch (c) {
1078 
1079     case '%':
1080 	if (quesarg == -1) {
1081 	    seterror(ERR_BADBANGARG);
1082 	    return (0);
1083 	}
1084 	if (*al < 0)
1085 	    *al = quesarg;
1086 	*ar = quesarg;
1087 	break;
1088 
1089     case '-':
1090 	if (*al < 0) {
1091 	    *al = 0;
1092 	    *ar = dol - 1;
1093 	    unreadc(c);
1094 	}
1095 	return (1);
1096 
1097     case '^':
1098 	if (*al < 0)
1099 	    *al = 1;
1100 	*ar = 1;
1101 	break;
1102 
1103     case '$':
1104 	if (*al < 0)
1105 	    *al = dol;
1106 	*ar = dol;
1107 	break;
1108 
1109     case '*':
1110 	if (*al < 0)
1111 	    *al = 1;
1112 	*ar = dol;
1113 	if (*ar < *al) {
1114 	    *ar = 0;
1115 	    *al = 1;
1116 	    return (1);
1117 	}
1118 	break;
1119 
1120     default:
1121 	if (Isdigit(c)) {
1122 	    i = 0;
1123 	    while (Isdigit(c)) {
1124 		i = i * 10 + c - '0';
1125 		c = getC(0);
1126 	    }
1127 	    if (i < 0)
1128 		i = dol + 1;
1129 	    if (*al < 0)
1130 		*al = i;
1131 	    *ar = i;
1132 	}
1133 	else if (*al < 0)
1134 	    *al = 0, *ar = dol;
1135 	else
1136 	    *ar = dol - 1;
1137 	unreadc(c);
1138 	break;
1139     }
1140     if (first) {
1141 	c = getC(0);
1142 	unreadc(c);
1143 	if (any("-$*", c))
1144 	    return (1);
1145     }
1146     if (*al > *ar || *ar > dol) {
1147 	seterror(ERR_BADBANGARG);
1148 	return (0);
1149     }
1150     return (1);
1151 
1152 }
1153 
1154 static struct wordent *
1155 gethent(Char sc)
1156 {
1157     struct Hist *hp;
1158     Char *np;
1159     eChar c;
1160     int     event;
1161     int    back = 0;
1162 
1163     c = (sc == HISTSUB && HISTSUB != '\0') ? (eChar)HIST : getC(0);
1164     if (c == (eChar)HIST) {
1165 	if (alhistp)
1166 	    return (alhistp);
1167 	event = eventno;
1168     }
1169     else
1170 	switch (c) {
1171 
1172 	case ':':
1173 	case '^':
1174 	case '$':
1175 	case '*':
1176 	case '%':
1177 	    ungetC(c);
1178 	    if (lastev == eventno && alhistp)
1179 		return (alhistp);
1180 	    event = lastev;
1181 	    break;
1182 
1183 	case '#':		/* !# is command being typed in (mrh) */
1184 	    if (--hleft == 0) {
1185 		seterror(ERR_HISTLOOP);
1186 		return (0);
1187 	    }
1188 	    else
1189 		return (&paraml);
1190 	    /* NOTREACHED */
1191 
1192 	case '-':
1193 	    back = 1;
1194 	    c = getC(0);
1195 	    /* FALLSTHROUGH */
1196 
1197 	default:
1198 	    if (any("(=~", c)) {
1199 		unreadc(c);
1200 		ungetC(HIST);
1201 		return (0);
1202 	    }
1203 	    Strbuf_terminate(&lhsb);
1204 	    lhsb.len = 0;
1205 	    event = 0;
1206 	    while (!cmap(c, _ESC | _META | _QF | _QB) && !any("^*-%${}:#", c)) {
1207 		if (event != -1 && Isdigit(c))
1208 		    event = event * 10 + c - '0';
1209 		else
1210 		    event = -1;
1211 		Strbuf_append1(&lhsb, c);
1212 		c = getC(0);
1213 	    }
1214 	    unreadc(c);
1215 	    if (lhsb.len == 0) {
1216 		lhsb.len = Strlen(lhsb.s); /* lhsb.s wasn't changed */
1217 		ungetC(HIST);
1218 		return (0);
1219 	    }
1220 	    Strbuf_terminate(&lhsb);
1221 	    if (event != -1) {
1222 		/*
1223 		 * History had only digits
1224 		 */
1225 		if (back)
1226 		    event = eventno + (alhistp == 0) - event;
1227 		break;
1228 	    }
1229 	    if (back) {
1230 		Strbuf_append1(&lhsb, '\0'); /* Allocate space */
1231 		Strbuf_terminate(&lhsb);
1232 		memmove(lhsb.s + 1, lhsb.s, (lhsb.len - 1) * sizeof (*lhsb.s));
1233 		lhsb.s[0] = '-';
1234 	    }
1235 	    hp = findev(lhsb.s, 0);
1236 	    if (hp)
1237 		lastev = hp->Hnum;
1238 	    return (&hp->Hlex);
1239 
1240 	case '?':
1241 	    Strbuf_terminate(&lhsb);
1242 	    lhsb.len = 0;
1243 	    for (;;) {
1244 		c = getC(0);
1245 		if (c == '\n') {
1246 		    unreadc(c);
1247 		    break;
1248 		}
1249 		if (c == '?')
1250 		    break;
1251 		Strbuf_append1(&lhsb, c);
1252 	    }
1253 	    if (lhsb.len == 0) {
1254 		lhsb.len = Strlen(lhsb.s); /* lhsb.s wasn't changed */
1255 		if (lhsb.len == 0) {
1256 		    seterror(ERR_NOSEARCH);
1257 		    return (0);
1258 		}
1259 	    }
1260 	    else
1261 		Strbuf_terminate(&lhsb);
1262 	    hp = findev(lhsb.s, 1);
1263 	    if (hp)
1264 		lastev = hp->Hnum;
1265 	    return (&hp->Hlex);
1266 	}
1267 
1268     for (hp = Histlist.Hnext; hp; hp = hp->Hnext)
1269 	if (hp->Hnum == event) {
1270 	    hp->Href = eventno;
1271 	    lastev = hp->Hnum;
1272 	    return (&hp->Hlex);
1273 	}
1274     np = putn((tcsh_number_t)event);
1275     seterror(ERR_NOEVENT, short2str(np));
1276     xfree(np);
1277     return (0);
1278 }
1279 
1280 static struct Hist *
1281 findev(Char *cp, int anyarg)
1282 {
1283     struct Hist *hp;
1284 
1285     for (hp = Histlist.Hnext; hp; hp = hp->Hnext) {
1286 	Char   *dp;
1287 	Char *p, *q;
1288 	struct wordent *lp = hp->Hlex.next;
1289 	int     argno = 0;
1290 
1291 	/*
1292 	 * The entries added by alias substitution don't have a newline but do
1293 	 * have a negative event number. Savehist() trims off these entries,
1294 	 * but it happens before alias expansion, too early to delete those
1295 	 * from the previous command.
1296 	 */
1297 	if (hp->Hnum < 0)
1298 	    continue;
1299 	if (lp->word[0] == '\n')
1300 	    continue;
1301 	if (!anyarg) {
1302 	    p = cp;
1303 	    q = lp->word;
1304 	    do
1305 		if (!*p)
1306 		    return (hp);
1307 	    while (*p++ == *q++);
1308 	    continue;
1309 	}
1310 	do {
1311 	    for (dp = lp->word; *dp; dp++) {
1312 		p = cp;
1313 		q = dp;
1314 		do
1315 		    if (!*p) {
1316 			quesarg = argno;
1317 			return (hp);
1318 		    }
1319 		while (*p++ == *q++);
1320 	    }
1321 	    lp = lp->next;
1322 	    argno++;
1323 	} while (lp->word[0] != '\n');
1324     }
1325     seterror(ERR_NOEVENT, short2str(cp));
1326     return (0);
1327 }
1328 
1329 
1330 static void
1331 setexclp(Char *cp)
1332 {
1333     if (cp && cp[0] == '\n')
1334 	return;
1335     exclp = cp;
1336 }
1337 
1338 void
1339 unreadc(Char c)
1340 {
1341     peekread = (Char) c;
1342 }
1343 
1344 eChar
1345 readc(int wanteof)
1346 {
1347     eChar c;
1348     static  int sincereal;	/* Number of real EOFs we've seen */
1349 
1350 #ifdef DEBUG_INP
1351     xprintf("readc\n");
1352 #endif
1353     if ((c = peekread) != 0) {
1354 	peekread = 0;
1355 	return (c);
1356     }
1357 
1358 top:
1359     aret = TCSH_F_SEEK;
1360     if (alvecp) {
1361 	arun = 1;
1362 #ifdef DEBUG_INP
1363 	xprintf("alvecp %c\n", *alvecp & 0xff);
1364 #endif
1365 	aret = TCSH_A_SEEK;
1366 	if ((c = *alvecp++) != 0)
1367 	    return (c);
1368 	if (alvec && *alvec) {
1369 		alvecp = *alvec++;
1370 		return (' ');
1371 	}
1372 	else {
1373 	    alvecp = NULL;
1374 	    aret = TCSH_F_SEEK;
1375 	    return('\n');
1376 	}
1377     }
1378     if (alvec) {
1379 	arun = 1;
1380 	if ((alvecp = *alvec) != 0) {
1381 	    alvec++;
1382 	    goto top;
1383 	}
1384 	/* Infinite source! */
1385 	return ('\n');
1386     }
1387     arun = 0;
1388     if (evalp) {
1389 	aret = TCSH_E_SEEK;
1390 	if ((c = *evalp++) != 0)
1391 	    return (c);
1392 	if (evalvec && *evalvec) {
1393 	    evalp = *evalvec++;
1394 	    return (' ');
1395 	}
1396 	aret = TCSH_F_SEEK;
1397 	evalp = 0;
1398     }
1399     if (evalvec) {
1400 	if (evalvec == INVPPTR) {
1401 	    doneinp = 1;
1402 	    reset();
1403 	}
1404 	if ((evalp = *evalvec) != 0) {
1405 	    evalvec++;
1406 	    goto top;
1407 	}
1408 	evalvec = INVPPTR;
1409 	return ('\n');
1410     }
1411     do {
1412 	if (arginp == INVPTR || onelflg == 1) {
1413 	    if (wanteof)
1414 		return CHAR_ERR;
1415 	    exitstat();
1416 	}
1417 	if (arginp) {
1418 	    if ((c = *arginp++) == 0) {
1419 		arginp = INVPTR;
1420 		return ('\n');
1421 	    }
1422 	    return (c);
1423 	}
1424 #ifdef BSDJOBS
1425 reread:
1426 #endif /* BSDJOBS */
1427 	c = bgetc();
1428 	if (c == CHAR_ERR) {
1429 #ifndef WINNT_NATIVE
1430 # ifndef POSIX
1431 #  ifdef TERMIO
1432 	    struct termio tty;
1433 #  else /* SGTTYB */
1434 	    struct sgttyb tty;
1435 #  endif /* TERMIO */
1436 # else /* POSIX */
1437 	    struct termios tty;
1438 # endif /* POSIX */
1439 #endif /* !WINNT_NATIVE */
1440 	    if (wanteof)
1441 		return CHAR_ERR;
1442 	    /* was isatty but raw with ignoreeof yields problems */
1443 #ifndef WINNT_NATIVE
1444 # ifndef POSIX
1445 #  ifdef TERMIO
1446 	    if (ioctl(SHIN, TCGETA, (ioctl_t) & tty) == 0 &&
1447 		(tty.c_lflag & ICANON))
1448 #  else /* GSTTYB */
1449 	    if (ioctl(SHIN, TIOCGETP, (ioctl_t) & tty) == 0 &&
1450 		(tty.sg_flags & RAW) == 0)
1451 #  endif /* TERMIO */
1452 # else /* POSIX */
1453 	    if (tcgetattr(SHIN, &tty) == 0 &&
1454 		(tty.c_lflag & ICANON))
1455 # endif /* POSIX */
1456 #else /* WINNT_NATIVE */
1457 	    if (isatty(SHIN))
1458 #endif /* !WINNT_NATIVE */
1459 	    {
1460 #ifdef BSDJOBS
1461 		pid_t ctpgrp;
1462 #endif /* BSDJOBS */
1463 
1464 		if (numeof != 0 && ++sincereal >= numeof)	/* Too many EOFs?  Bye! */
1465 		    goto oops;
1466 #ifdef BSDJOBS
1467 		if (tpgrp != -1 &&
1468 		    (ctpgrp = tcgetpgrp(FSHTTY)) != -1 &&
1469 		    tpgrp != ctpgrp) {
1470 		    (void) tcsetpgrp(FSHTTY, tpgrp);
1471 # ifdef _SEQUENT_
1472 		    if (ctpgrp)
1473 # endif /* _SEQUENT */
1474 		    (void) killpg(ctpgrp, SIGHUP);
1475 # ifdef notdef
1476 		    /*
1477 		     * With the walking process group fix, this message
1478 		     * is now obsolete. As the foreground process group
1479 		     * changes, the shell needs to adjust. Well too bad.
1480 		     */
1481 		    xprintf(CGETS(16, 1, "Reset tty pgrp from %d to %d\n"),
1482 			    (int)ctpgrp, (int)tpgrp);
1483 # endif /* notdef */
1484 		    goto reread;
1485 		}
1486 #endif /* BSDJOBS */
1487 		/* What follows is complicated EOF handling -- sterling@netcom.com */
1488 		/* First, we check to see if we have ignoreeof set */
1489 		if (adrof(STRignoreeof)) {
1490 			/* If so, we check for any stopped jobs only on the first EOF */
1491 			if ((sincereal == 1) && (chkstop == 0)) {
1492 				panystop(1);
1493 			}
1494 		} else {
1495 			/* If we don't have ignoreeof set, always check for stopped jobs */
1496 			if (chkstop == 0) {
1497 				panystop(1);
1498 			}
1499 		}
1500 		/* At this point, if there were stopped jobs, we would have already
1501 		 * called reset().  If we got this far, assume we can print an
1502 		 * exit/logout message if we ignoreeof, or just exit.
1503 		 */
1504 		if (adrof(STRignoreeof)) {
1505 			/* If so, tell the user to use exit or logout */
1506 		    if (loginsh) {
1507 				xprintf("%s", CGETS(16, 2,
1508 					"\nUse \"logout\" to logout.\n"));
1509 		   	} else {
1510 				xprintf(CGETS(16, 3,
1511 					"\nUse \"exit\" to leave %s.\n"),
1512 					progname);
1513 			}
1514 		    reset();
1515 		} else {
1516 			/* If we don't have ignoreeof set, just fall through */
1517 			;	/* EMPTY */
1518 		}
1519 	    }
1520     oops:
1521 	    doneinp = 1;
1522 	    reset();
1523 	}
1524 	sincereal = 0;
1525 	if (c == '\n' && onelflg)
1526 	    onelflg--;
1527     } while (c == 0);
1528     Strbuf_append1(&histline, c);
1529     return (c);
1530 }
1531 
1532 static void
1533 balloc(int buf)
1534 {
1535     Char **nfbuf;
1536 
1537     while (buf >= fblocks) {
1538 	nfbuf = xcalloc(fblocks + 2, sizeof(Char **));
1539 	if (fbuf) {
1540 	    (void) blkcpy(nfbuf, fbuf);
1541 	    xfree(fbuf);
1542 	}
1543 	fbuf = nfbuf;
1544 	fbuf[fblocks] = xcalloc(BUFSIZE, sizeof(Char));
1545 	fblocks++;
1546     }
1547 }
1548 
1549 ssize_t
1550 wide_read(int fildes, Char *buf, size_t nchars, int use_fclens)
1551 {
1552     char cbuf[BUFSIZE + 1];
1553     ssize_t res, r = 0;
1554     size_t partial;
1555     int err;
1556 
1557     if (nchars == 0)
1558 	return 0;
1559     assert (nchars <= sizeof(cbuf) / sizeof(*cbuf));
1560     USE(use_fclens);
1561     res = 0;
1562     partial = 0;
1563     do {
1564 	size_t i;
1565 	size_t len = nchars > partial ? nchars - partial : 1;
1566 
1567 	if (partial + len >= sizeof(cbuf) / sizeof(*cbuf))
1568 	    break;
1569 
1570 	r = xread(fildes, cbuf + partial, len);
1571 
1572 	if (partial == 0 && r <= 0)
1573 	    break;
1574 	partial += r;
1575 	i = 0;
1576 	while (i < partial && nchars != 0) {
1577 	    int tlen;
1578 
1579 	    tlen = normal_mbtowc(buf + res, cbuf + i, partial - i);
1580 	    if (tlen == -1) {
1581 	        reset_mbtowc();
1582 		if ((partial - i) < MB_LEN_MAX && r > 0)
1583 		    /* Maybe a partial character and there is still a chance
1584 		       to read more */
1585 		    break;
1586 		buf[res] = (unsigned char)cbuf[i] | INVALID_BYTE;
1587 	    }
1588 	    if (tlen <= 0)
1589 		tlen = 1;
1590 #ifdef WIDE_STRINGS
1591 	    if (use_fclens)
1592 		fclens[res] = tlen;
1593 #endif
1594 	    i += tlen;
1595 	    res++;
1596 	    nchars--;
1597 	}
1598 	if (i != partial)
1599 	    memmove(cbuf, cbuf + i, partial - i);
1600 	partial -= i;
1601     } while (partial != 0 && nchars > 0);
1602     /* Throwing away possible partial multibyte characters on error if the
1603        stream is not seekable */
1604     err = errno;
1605     lseek(fildes, -(off_t)partial, L_INCR);
1606     errno = err;
1607     return res != 0 ? res : r;
1608 }
1609 
1610 static eChar
1611 bgetc(void)
1612 {
1613     Char ch;
1614     int c, off, buf;
1615     int numleft = 0, roomleft;
1616 
1617     if (cantell) {
1618 	if (fseekp < fbobp || fseekp > feobp) {
1619 	    fbobp = feobp = fseekp;
1620 	    (void) lseek(SHIN, fseekp, L_SET);
1621 	}
1622 	if (fseekp == feobp) {
1623 #ifdef WIDE_STRINGS
1624 	    off_t bytes;
1625 	    size_t i;
1626 
1627 	    bytes = fbobp;
1628 	    for (i = 0; i < (size_t)(feobp - fbobp); i++)
1629 		bytes += fclens[i];
1630 	    fseekp = feobp = bytes;
1631 #endif
1632 	    fbobp = feobp;
1633 	    c = wide_read(SHIN, fbuf[0], BUFSIZE, 1);
1634 #ifdef convex
1635 	    if (c < 0)
1636 		stderror(ERR_SYSTEM, progname, strerror(errno));
1637 #endif /* convex */
1638 	    if (c <= 0)
1639 		return CHAR_ERR;
1640 	    feobp += c;
1641 	}
1642 #if !defined(WINNT_NATIVE) && !defined(__CYGWIN__)
1643 	ch = fbuf[0][fseekp - fbobp];
1644 	fseekp++;
1645 #else
1646 	do {
1647 	    ch = fbuf[0][fseekp - fbobp];
1648 	    fseekp++;
1649 	} while(ch == '\r');
1650 #endif /* !WINNT_NATIVE && !__CYGWIN__ */
1651 	return (ch);
1652     }
1653 
1654     while (fseekp >= feobp) {
1655 	if ((editing
1656 #if defined(FILEC) && defined(TIOCSTI)
1657 	    || filec
1658 #endif /* FILEC && TIOCSTI */
1659 	    ) && intty) {		/* then use twenex routine */
1660 	    fseekp = feobp;		/* where else? */
1661 #if defined(FILEC) && defined(TIOCSTI)
1662 	    if (!editing)
1663 		c = numleft = tenex(InputBuf, BUFSIZE);
1664 	    else
1665 #endif /* FILEC && TIOCSTI */
1666 	    c = numleft = Inputl();	/* PWP: get a line */
1667 	    while (numleft > 0) {
1668 		off = (int) feobp % BUFSIZE;
1669 		buf = (int) feobp / BUFSIZE;
1670 		balloc(buf);
1671 		roomleft = BUFSIZE - off;
1672 		if (roomleft > numleft)
1673 		    roomleft = numleft;
1674 		(void) memcpy(fbuf[buf] + off, InputBuf + c - numleft,
1675 			      roomleft * sizeof(Char));
1676 		numleft -= roomleft;
1677 		feobp += roomleft;
1678 	    }
1679 	} else {
1680 	    off = (int) feobp % BUFSIZE;
1681 	    buf = (int) feobp / BUFSIZE;
1682 	    balloc(buf);
1683 	    roomleft = BUFSIZE - off;
1684 	    c = wide_read(SHIN, fbuf[buf] + off, roomleft, 0);
1685 	    if (c > 0)
1686 		feobp += c;
1687 	}
1688 	if (c == 0 || (c < 0 && fixio(SHIN, errno) == -1))
1689 	    return CHAR_ERR;
1690     }
1691 #ifdef SIG_WINDOW
1692     if (windowchg)
1693 	(void) check_window_size(0);	/* for window systems */
1694 #endif /* SIG_WINDOW */
1695 #if !defined(WINNT_NATIVE) && !defined(__CYGWIN__)
1696     ch = fbuf[(int) fseekp / BUFSIZE][(int) fseekp % BUFSIZE];
1697     fseekp++;
1698 #else
1699     do {
1700 	ch = fbuf[(int) fseekp / BUFSIZE][(int) fseekp % BUFSIZE];
1701 	fseekp++;
1702     } while(ch == '\r');
1703 #endif /* !WINNT_NATIVE && !__CYGWIN__ */
1704     return (ch);
1705 }
1706 
1707 static void
1708 bfree(void)
1709 {
1710     int sb, i;
1711 
1712     if (cantell)
1713 	return;
1714     if (whyles)
1715 	return;
1716     sb = (int) (fseekp - 1) / BUFSIZE;
1717     if (sb > 0) {
1718 	for (i = 0; i < sb; i++)
1719 	    xfree(fbuf[i]);
1720 	(void) blkcpy(fbuf, &fbuf[sb]);
1721 	fseekp -= BUFSIZE * sb;
1722 	feobp -= BUFSIZE * sb;
1723 	fblocks -= sb;
1724     }
1725 }
1726 
1727 void
1728 bseek(struct Ain *l)
1729 {
1730     switch (aret = l->type) {
1731     case TCSH_E_SEEK:
1732 	evalvec = l->a_seek;
1733 	evalp = l->c_seek;
1734 #ifdef DEBUG_SEEK
1735 	xprintf(CGETS(16, 4, "seek to eval %x %x\n"), evalvec, evalp);
1736 #endif
1737 	return;
1738     case TCSH_A_SEEK:
1739 	alvec = l->a_seek;
1740 	alvecp = l->c_seek;
1741 #ifdef DEBUG_SEEK
1742 	xprintf(CGETS(16, 5, "seek to alias %x %x\n"), alvec, alvecp);
1743 #endif
1744 	return;
1745     case TCSH_F_SEEK:
1746 #ifdef DEBUG_SEEK
1747 	xprintf(CGETS(16, 6, "seek to file %x\n"), fseekp);
1748 #endif
1749 	fseekp = l->f_seek;
1750 #ifdef WIDE_STRINGS
1751 	if (cantell) {
1752 	    if (fseekp >= fbobp && feobp >= fbobp) {
1753 		size_t i;
1754 		off_t o;
1755 
1756 		o = fbobp;
1757 		for (i = 0; i < (size_t)(feobp - fbobp); i++) {
1758 		    if (fseekp == o) {
1759 			fseekp = fbobp + i;
1760 			return;
1761 		    }
1762 		    o += fclens[i];
1763 		}
1764 		if (fseekp == o) {
1765 		    fseekp = feobp;
1766 		    return;
1767 		}
1768 	    }
1769 	    fbobp = feobp = fseekp + 1; /* To force lseek() */
1770 	}
1771 #endif
1772 	return;
1773     default:
1774 	xprintf(CGETS(16, 7, "Bad seek type %d\n"), aret);
1775 	abort();
1776     }
1777 }
1778 
1779 /* any similarity to bell telephone is purely accidental */
1780 void
1781 btell(struct Ain *l)
1782 {
1783     switch (l->type = aret) {
1784     case TCSH_E_SEEK:
1785 	l->a_seek = evalvec;
1786 	l->c_seek = evalp;
1787 #ifdef DEBUG_SEEK
1788 	xprintf(CGETS(16, 8, "tell eval %x %x\n"), evalvec, evalp);
1789 #endif
1790 	return;
1791     case TCSH_A_SEEK:
1792 	l->a_seek = alvec;
1793 	l->c_seek = alvecp;
1794 #ifdef DEBUG_SEEK
1795 	xprintf(CGETS(16, 9, "tell alias %x %x\n"), alvec, alvecp);
1796 #endif
1797 	return;
1798     case TCSH_F_SEEK:
1799 #ifdef WIDE_STRINGS
1800 	if (cantell && fseekp >= fbobp && fseekp <= feobp) {
1801 	    size_t i;
1802 
1803 	    l->f_seek = fbobp;
1804 	    for (i = 0; i < (size_t)(fseekp - fbobp); i++)
1805 		l->f_seek += fclens[i];
1806 	} else
1807 #endif
1808 	    /*SUPPRESS 112*/
1809 	    l->f_seek = fseekp;
1810 	l->a_seek = NULL;
1811 #ifdef DEBUG_SEEK
1812 	xprintf(CGETS(16, 10, "tell file %x\n"), fseekp);
1813 #endif
1814 	return;
1815     default:
1816 	xprintf(CGETS(16, 7, "Bad seek type %d\n"), aret);
1817 	abort();
1818     }
1819 }
1820 
1821 void
1822 btoeof(void)
1823 {
1824     (void) lseek(SHIN, (off_t) 0, L_XTND);
1825     aret = TCSH_F_SEEK;
1826     fseekp = feobp;
1827     alvec = NULL;
1828     alvecp = NULL;
1829     evalvec = NULL;
1830     evalp = NULL;
1831     wfree();
1832     bfree();
1833 }
1834 
1835 void
1836 settell(void)
1837 {
1838     off_t x;
1839     cantell = 0;
1840     if (arginp || onelflg || intty)
1841 	return;
1842     if ((x = lseek(SHIN, (off_t) 0, L_INCR)) == -1)
1843 	return;
1844     fbuf = xcalloc(2, sizeof(Char **));
1845     fblocks = 1;
1846     fbuf[0] = xcalloc(BUFSIZE, sizeof(Char));
1847     fseekp = fbobp = feobp = x;
1848     cantell = 1;
1849 }
1850