xref: /freebsd/contrib/one-true-awk/run.c (revision 5956d97f4b3204318ceb6aa9c77bd0bc6ea87a41)
1 /****************************************************************
2 Copyright (C) Lucent Technologies 1997
3 All Rights Reserved
4 
5 Permission to use, copy, modify, and distribute this software and
6 its documentation for any purpose and without fee is hereby
7 granted, provided that the above copyright notice appear in all
8 copies and that both that the copyright notice and this
9 permission notice and warranty disclaimer appear in supporting
10 documentation, and that the name Lucent Technologies or any of
11 its entities not be used in advertising or publicity pertaining
12 to distribution of the software without specific, written prior
13 permission.
14 
15 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
16 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
17 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
18 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
20 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
21 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
22 THIS SOFTWARE.
23 ****************************************************************/
24 
25 #define DEBUG
26 #include <stdio.h>
27 #include <ctype.h>
28 #include <errno.h>
29 #include <wchar.h>
30 #include <wctype.h>
31 #include <fcntl.h>
32 #include <setjmp.h>
33 #include <limits.h>
34 #include <math.h>
35 #include <string.h>
36 #include <stdlib.h>
37 #include <time.h>
38 #include <sys/types.h>
39 #include <sys/wait.h>
40 #include "awk.h"
41 #include "awkgram.tab.h"
42 
43 static void stdinit(void);
44 static void flush_all(void);
45 
46 #if 1
47 #define tempfree(x)	do { if (istemp(x)) tfree(x); } while (/*CONSTCOND*/0)
48 #else
49 void tempfree(Cell *p) {
50 	if (p->ctype == OCELL && (p->csub < CUNK || p->csub > CFREE)) {
51 		WARNING("bad csub %d in Cell %d %s",
52 			p->csub, p->ctype, p->sval);
53 	}
54 	if (istemp(p))
55 		tfree(p);
56 }
57 #endif
58 
59 /* do we really need these? */
60 /* #ifdef _NFILE */
61 /* #ifndef FOPEN_MAX */
62 /* #define FOPEN_MAX _NFILE */
63 /* #endif */
64 /* #endif */
65 /*  */
66 /* #ifndef	FOPEN_MAX */
67 /* #define	FOPEN_MAX	40 */	/* max number of open files */
68 /* #endif */
69 /*  */
70 /* #ifndef RAND_MAX */
71 /* #define RAND_MAX	32767 */	/* all that ansi guarantees */
72 /* #endif */
73 
74 jmp_buf env;
75 extern	int	pairstack[];
76 extern	Awkfloat	srand_seed;
77 
78 Node	*winner = NULL;	/* root of parse tree */
79 Cell	*tmps;		/* free temporary cells for execution */
80 
81 static Cell	truecell	={ OBOOL, BTRUE, 0, 0, 1.0, NUM, NULL, NULL };
82 Cell	*True	= &truecell;
83 static Cell	falsecell	={ OBOOL, BFALSE, 0, 0, 0.0, NUM, NULL, NULL };
84 Cell	*False	= &falsecell;
85 static Cell	breakcell	={ OJUMP, JBREAK, 0, 0, 0.0, NUM, NULL, NULL };
86 Cell	*jbreak	= &breakcell;
87 static Cell	contcell	={ OJUMP, JCONT, 0, 0, 0.0, NUM, NULL, NULL };
88 Cell	*jcont	= &contcell;
89 static Cell	nextcell	={ OJUMP, JNEXT, 0, 0, 0.0, NUM, NULL, NULL };
90 Cell	*jnext	= &nextcell;
91 static Cell	nextfilecell	={ OJUMP, JNEXTFILE, 0, 0, 0.0, NUM, NULL, NULL };
92 Cell	*jnextfile	= &nextfilecell;
93 static Cell	exitcell	={ OJUMP, JEXIT, 0, 0, 0.0, NUM, NULL, NULL };
94 Cell	*jexit	= &exitcell;
95 static Cell	retcell		={ OJUMP, JRET, 0, 0, 0.0, NUM, NULL, NULL };
96 Cell	*jret	= &retcell;
97 static Cell	tempcell	={ OCELL, CTEMP, 0, EMPTY, 0.0, NUM|STR|DONTFREE, NULL, NULL };
98 
99 Node	*curnode = NULL;	/* the node being executed, for debugging */
100 
101 /* buffer memory management */
102 int adjbuf(char **pbuf, int *psiz, int minlen, int quantum, char **pbptr,
103 	const char *whatrtn)
104 /* pbuf:    address of pointer to buffer being managed
105  * psiz:    address of buffer size variable
106  * minlen:  minimum length of buffer needed
107  * quantum: buffer size quantum
108  * pbptr:   address of movable pointer into buffer, or 0 if none
109  * whatrtn: name of the calling routine if failure should cause fatal error
110  *
111  * return   0 for realloc failure, !=0 for success
112  */
113 {
114 	if (minlen > *psiz) {
115 		char *tbuf;
116 		int rminlen = quantum ? minlen % quantum : 0;
117 		int boff = pbptr ? *pbptr - *pbuf : 0;
118 		/* round up to next multiple of quantum */
119 		if (rminlen)
120 			minlen += quantum - rminlen;
121 		tbuf = (char *) realloc(*pbuf, minlen);
122 		DPRINTF("adjbuf %s: %d %d (pbuf=%p, tbuf=%p)\n", whatrtn, *psiz, minlen, (void*)*pbuf, (void*)tbuf);
123 		if (tbuf == NULL) {
124 			if (whatrtn)
125 				FATAL("out of memory in %s", whatrtn);
126 			return 0;
127 		}
128 		*pbuf = tbuf;
129 		*psiz = minlen;
130 		if (pbptr)
131 			*pbptr = tbuf + boff;
132 	}
133 	return 1;
134 }
135 
136 void run(Node *a)	/* execution of parse tree starts here */
137 {
138 
139 	stdinit();
140 	execute(a);
141 	closeall();
142 }
143 
144 Cell *execute(Node *u)	/* execute a node of the parse tree */
145 {
146 	Cell *(*proc)(Node **, int);
147 	Cell *x;
148 	Node *a;
149 
150 	if (u == NULL)
151 		return(True);
152 	for (a = u; ; a = a->nnext) {
153 		curnode = a;
154 		if (isvalue(a)) {
155 			x = (Cell *) (a->narg[0]);
156 			if (isfld(x) && !donefld)
157 				fldbld();
158 			else if (isrec(x) && !donerec)
159 				recbld();
160 			return(x);
161 		}
162 		if (notlegal(a->nobj))	/* probably a Cell* but too risky to print */
163 			FATAL("illegal statement");
164 		proc = proctab[a->nobj-FIRSTTOKEN];
165 		x = (*proc)(a->narg, a->nobj);
166 		if (isfld(x) && !donefld)
167 			fldbld();
168 		else if (isrec(x) && !donerec)
169 			recbld();
170 		if (isexpr(a))
171 			return(x);
172 		if (isjump(x))
173 			return(x);
174 		if (a->nnext == NULL)
175 			return(x);
176 		tempfree(x);
177 	}
178 }
179 
180 
181 Cell *program(Node **a, int n)	/* execute an awk program */
182 {				/* a[0] = BEGIN, a[1] = body, a[2] = END */
183 	Cell *x;
184 
185 	if (setjmp(env) != 0)
186 		goto ex;
187 	if (a[0]) {		/* BEGIN */
188 		x = execute(a[0]);
189 		if (isexit(x))
190 			return(True);
191 		if (isjump(x))
192 			FATAL("illegal break, continue, next or nextfile from BEGIN");
193 		tempfree(x);
194 	}
195 	if (a[1] || a[2])
196 		while (getrec(&record, &recsize, true) > 0) {
197 			x = execute(a[1]);
198 			if (isexit(x))
199 				break;
200 			tempfree(x);
201 		}
202   ex:
203 	if (setjmp(env) != 0)	/* handles exit within END */
204 		goto ex1;
205 	if (a[2]) {		/* END */
206 		x = execute(a[2]);
207 		if (isbreak(x) || isnext(x) || iscont(x))
208 			FATAL("illegal break, continue, next or nextfile from END");
209 		tempfree(x);
210 	}
211   ex1:
212 	return(True);
213 }
214 
215 struct Frame {	/* stack frame for awk function calls */
216 	int nargs;	/* number of arguments in this call */
217 	Cell *fcncell;	/* pointer to Cell for function */
218 	Cell **args;	/* pointer to array of arguments after execute */
219 	Cell *retval;	/* return value */
220 };
221 
222 #define	NARGS	50	/* max args in a call */
223 
224 struct Frame *frame = NULL;	/* base of stack frames; dynamically allocated */
225 int	nframe = 0;		/* number of frames allocated */
226 struct Frame *frp = NULL;	/* frame pointer. bottom level unused */
227 
228 Cell *call(Node **a, int n)	/* function call.  very kludgy and fragile */
229 {
230 	static const Cell newcopycell = { OCELL, CCOPY, 0, EMPTY, 0.0, NUM|STR|DONTFREE, NULL, NULL };
231 	int i, ncall, ndef;
232 	int freed = 0; /* handles potential double freeing when fcn & param share a tempcell */
233 	Node *x;
234 	Cell *args[NARGS], *oargs[NARGS];	/* BUG: fixed size arrays */
235 	Cell *y, *z, *fcn;
236 	char *s;
237 
238 	fcn = execute(a[0]);	/* the function itself */
239 	s = fcn->nval;
240 	if (!isfcn(fcn))
241 		FATAL("calling undefined function %s", s);
242 	if (frame == NULL) {
243 		frp = frame = (struct Frame *) calloc(nframe += 100, sizeof(*frame));
244 		if (frame == NULL)
245 			FATAL("out of space for stack frames calling %s", s);
246 	}
247 	for (ncall = 0, x = a[1]; x != NULL; x = x->nnext)	/* args in call */
248 		ncall++;
249 	ndef = (int) fcn->fval;			/* args in defn */
250 	DPRINTF("calling %s, %d args (%d in defn), frp=%d\n", s, ncall, ndef, (int) (frp-frame));
251 	if (ncall > ndef)
252 		WARNING("function %s called with %d args, uses only %d",
253 			s, ncall, ndef);
254 	if (ncall + ndef > NARGS)
255 		FATAL("function %s has %d arguments, limit %d", s, ncall+ndef, NARGS);
256 	for (i = 0, x = a[1]; x != NULL; i++, x = x->nnext) {	/* get call args */
257 		DPRINTF("evaluate args[%d], frp=%d:\n", i, (int) (frp-frame));
258 		y = execute(x);
259 		oargs[i] = y;
260 		DPRINTF("args[%d]: %s %f <%s>, t=%o\n",
261 			i, NN(y->nval), y->fval, isarr(y) ? "(array)" : NN(y->sval), y->tval);
262 		if (isfcn(y))
263 			FATAL("can't use function %s as argument in %s", y->nval, s);
264 		if (isarr(y))
265 			args[i] = y;	/* arrays by ref */
266 		else
267 			args[i] = copycell(y);
268 		tempfree(y);
269 	}
270 	for ( ; i < ndef; i++) {	/* add null args for ones not provided */
271 		args[i] = gettemp();
272 		*args[i] = newcopycell;
273 	}
274 	frp++;	/* now ok to up frame */
275 	if (frp >= frame + nframe) {
276 		int dfp = frp - frame;	/* old index */
277 		frame = (struct Frame *) realloc(frame, (nframe += 100) * sizeof(*frame));
278 		if (frame == NULL)
279 			FATAL("out of space for stack frames in %s", s);
280 		frp = frame + dfp;
281 	}
282 	frp->fcncell = fcn;
283 	frp->args = args;
284 	frp->nargs = ndef;	/* number defined with (excess are locals) */
285 	frp->retval = gettemp();
286 
287 	DPRINTF("start exec of %s, frp=%d\n", s, (int) (frp-frame));
288 	y = execute((Node *)(fcn->sval));	/* execute body */
289 	DPRINTF("finished exec of %s, frp=%d\n", s, (int) (frp-frame));
290 
291 	for (i = 0; i < ndef; i++) {
292 		Cell *t = frp->args[i];
293 		if (isarr(t)) {
294 			if (t->csub == CCOPY) {
295 				if (i >= ncall) {
296 					freesymtab(t);
297 					t->csub = CTEMP;
298 					tempfree(t);
299 				} else {
300 					oargs[i]->tval = t->tval;
301 					oargs[i]->tval &= ~(STR|NUM|DONTFREE);
302 					oargs[i]->sval = t->sval;
303 					tempfree(t);
304 				}
305 			}
306 		} else if (t != y) {	/* kludge to prevent freeing twice */
307 			t->csub = CTEMP;
308 			tempfree(t);
309 		} else if (t == y && t->csub == CCOPY) {
310 			t->csub = CTEMP;
311 			tempfree(t);
312 			freed = 1;
313 		}
314 	}
315 	tempfree(fcn);
316 	if (isexit(y) || isnext(y))
317 		return y;
318 	if (freed == 0) {
319 		tempfree(y);	/* don't free twice! */
320 	}
321 	z = frp->retval;			/* return value */
322 	DPRINTF("%s returns %g |%s| %o\n", s, getfval(z), getsval(z), z->tval);
323 	frp--;
324 	return(z);
325 }
326 
327 Cell *copycell(Cell *x)	/* make a copy of a cell in a temp */
328 {
329 	Cell *y;
330 
331 	/* copy is not constant or field */
332 
333 	y = gettemp();
334 	y->tval = x->tval & ~(CON|FLD|REC);
335 	y->csub = CCOPY;	/* prevents freeing until call is over */
336 	y->nval = x->nval;	/* BUG? */
337 	if (isstr(x) /* || x->ctype == OCELL */) {
338 		y->sval = tostring(x->sval);
339 		y->tval &= ~DONTFREE;
340 	} else
341 		y->tval |= DONTFREE;
342 	y->fval = x->fval;
343 	return y;
344 }
345 
346 Cell *arg(Node **a, int n)	/* nth argument of a function */
347 {
348 
349 	n = ptoi(a[0]);	/* argument number, counting from 0 */
350 	DPRINTF("arg(%d), frp->nargs=%d\n", n, frp->nargs);
351 	if (n+1 > frp->nargs)
352 		FATAL("argument #%d of function %s was not supplied",
353 			n+1, frp->fcncell->nval);
354 	return frp->args[n];
355 }
356 
357 Cell *jump(Node **a, int n)	/* break, continue, next, nextfile, return */
358 {
359 	Cell *y;
360 
361 	switch (n) {
362 	case EXIT:
363 		if (a[0] != NULL) {
364 			y = execute(a[0]);
365 			errorflag = (int) getfval(y);
366 			tempfree(y);
367 		}
368 		longjmp(env, 1);
369 	case RETURN:
370 		if (a[0] != NULL) {
371 			y = execute(a[0]);
372 			if ((y->tval & (STR|NUM)) == (STR|NUM)) {
373 				setsval(frp->retval, getsval(y));
374 				frp->retval->fval = getfval(y);
375 				frp->retval->tval |= NUM;
376 			}
377 			else if (y->tval & STR)
378 				setsval(frp->retval, getsval(y));
379 			else if (y->tval & NUM)
380 				setfval(frp->retval, getfval(y));
381 			else		/* can't happen */
382 				FATAL("bad type variable %d", y->tval);
383 			tempfree(y);
384 		}
385 		return(jret);
386 	case NEXT:
387 		return(jnext);
388 	case NEXTFILE:
389 		nextfile();
390 		return(jnextfile);
391 	case BREAK:
392 		return(jbreak);
393 	case CONTINUE:
394 		return(jcont);
395 	default:	/* can't happen */
396 		FATAL("illegal jump type %d", n);
397 	}
398 	return 0;	/* not reached */
399 }
400 
401 Cell *awkgetline(Node **a, int n)	/* get next line from specific input */
402 {		/* a[0] is variable, a[1] is operator, a[2] is filename */
403 	Cell *r, *x;
404 	extern Cell **fldtab;
405 	FILE *fp;
406 	char *buf;
407 	int bufsize = recsize;
408 	int mode;
409 	bool newflag;
410 	double result;
411 
412 	if ((buf = (char *) malloc(bufsize)) == NULL)
413 		FATAL("out of memory in getline");
414 
415 	fflush(stdout);	/* in case someone is waiting for a prompt */
416 	r = gettemp();
417 	if (a[1] != NULL) {		/* getline < file */
418 		x = execute(a[2]);		/* filename */
419 		mode = ptoi(a[1]);
420 		if (mode == '|')		/* input pipe */
421 			mode = LE;	/* arbitrary flag */
422 		fp = openfile(mode, getsval(x), &newflag);
423 		tempfree(x);
424 		if (fp == NULL)
425 			n = -1;
426 		else
427 			n = readrec(&buf, &bufsize, fp, newflag);
428 		if (n <= 0) {
429 			;
430 		} else if (a[0] != NULL) {	/* getline var <file */
431 			x = execute(a[0]);
432 			setsval(x, buf);
433 			if (is_number(x->sval, & result)) {
434 				x->fval = result;
435 				x->tval |= NUM;
436 			}
437 			tempfree(x);
438 		} else {			/* getline <file */
439 			setsval(fldtab[0], buf);
440 			if (is_number(fldtab[0]->sval, & result)) {
441 				fldtab[0]->fval = result;
442 				fldtab[0]->tval |= NUM;
443 			}
444 		}
445 	} else {			/* bare getline; use current input */
446 		if (a[0] == NULL)	/* getline */
447 			n = getrec(&record, &recsize, true);
448 		else {			/* getline var */
449 			n = getrec(&buf, &bufsize, false);
450 			x = execute(a[0]);
451 			setsval(x, buf);
452 			if (is_number(x->sval, & result)) {
453 				x->fval = result;
454 				x->tval |= NUM;
455 			}
456 			tempfree(x);
457 		}
458 	}
459 	setfval(r, (Awkfloat) n);
460 	free(buf);
461 	return r;
462 }
463 
464 Cell *getnf(Node **a, int n)	/* get NF */
465 {
466 	if (!donefld)
467 		fldbld();
468 	return (Cell *) a[0];
469 }
470 
471 static char *
472 makearraystring(Node *p, const char *func)
473 {
474 	char *buf;
475 	int bufsz = recsize;
476 	size_t blen;
477 
478 	if ((buf = (char *) malloc(bufsz)) == NULL) {
479 		FATAL("%s: out of memory", func);
480 	}
481 
482 	blen = 0;
483 	buf[blen] = '\0';
484 
485 	for (; p; p = p->nnext) {
486 		Cell *x = execute(p);	/* expr */
487 		char *s = getsval(x);
488 		size_t seplen = strlen(getsval(subseploc));
489 		size_t nsub = p->nnext ? seplen : 0;
490 		size_t slen = strlen(s);
491 		size_t tlen = blen + slen + nsub;
492 
493 		if (!adjbuf(&buf, &bufsz, tlen + 1, recsize, 0, func)) {
494 			FATAL("%s: out of memory %s[%s...]",
495 			    func, x->nval, buf);
496 		}
497 		memcpy(buf + blen, s, slen);
498 		if (nsub) {
499 			memcpy(buf + blen + slen, *SUBSEP, nsub);
500 		}
501 		buf[tlen] = '\0';
502 		blen = tlen;
503 		tempfree(x);
504 	}
505 	return buf;
506 }
507 
508 Cell *array(Node **a, int n)	/* a[0] is symtab, a[1] is list of subscripts */
509 {
510 	Cell *x, *z;
511 	char *buf;
512 
513 	x = execute(a[0]);	/* Cell* for symbol table */
514 	buf = makearraystring(a[1], __func__);
515 	if (!isarr(x)) {
516 		DPRINTF("making %s into an array\n", NN(x->nval));
517 		if (freeable(x))
518 			xfree(x->sval);
519 		x->tval &= ~(STR|NUM|DONTFREE);
520 		x->tval |= ARR;
521 		x->sval = (char *) makesymtab(NSYMTAB);
522 	}
523 	z = setsymtab(buf, "", 0.0, STR|NUM, (Array *) x->sval);
524 	z->ctype = OCELL;
525 	z->csub = CVAR;
526 	tempfree(x);
527 	free(buf);
528 	return(z);
529 }
530 
531 Cell *awkdelete(Node **a, int n)	/* a[0] is symtab, a[1] is list of subscripts */
532 {
533 	Cell *x;
534 
535 	x = execute(a[0]);	/* Cell* for symbol table */
536 	if (x == symtabloc) {
537 		FATAL("cannot delete SYMTAB or its elements");
538 	}
539 	if (!isarr(x))
540 		return True;
541 	if (a[1] == NULL) {	/* delete the elements, not the table */
542 		freesymtab(x);
543 		x->tval &= ~STR;
544 		x->tval |= ARR;
545 		x->sval = (char *) makesymtab(NSYMTAB);
546 	} else {
547 		char *buf = makearraystring(a[1], __func__);
548 		freeelem(x, buf);
549 		free(buf);
550 	}
551 	tempfree(x);
552 	return True;
553 }
554 
555 Cell *intest(Node **a, int n)	/* a[0] is index (list), a[1] is symtab */
556 {
557 	Cell *ap, *k;
558 	char *buf;
559 
560 	ap = execute(a[1]);	/* array name */
561 	if (!isarr(ap)) {
562 		DPRINTF("making %s into an array\n", ap->nval);
563 		if (freeable(ap))
564 			xfree(ap->sval);
565 		ap->tval &= ~(STR|NUM|DONTFREE);
566 		ap->tval |= ARR;
567 		ap->sval = (char *) makesymtab(NSYMTAB);
568 	}
569 	buf = makearraystring(a[0], __func__);
570 	k = lookup(buf, (Array *) ap->sval);
571 	tempfree(ap);
572 	free(buf);
573 	if (k == NULL)
574 		return(False);
575 	else
576 		return(True);
577 }
578 
579 
580 Cell *matchop(Node **a, int n)	/* ~ and match() */
581 {
582 	Cell *x, *y;
583 	char *s, *t;
584 	int i;
585 	fa *pfa;
586 	int (*mf)(fa *, const char *) = match, mode = 0;
587 
588 	if (n == MATCHFCN) {
589 		mf = pmatch;
590 		mode = 1;
591 	}
592 	x = execute(a[1]);	/* a[1] = target text */
593 	s = getsval(x);
594 	if (a[0] == NULL)	/* a[1] == 0: already-compiled reg expr */
595 		i = (*mf)((fa *) a[2], s);
596 	else {
597 		y = execute(a[2]);	/* a[2] = regular expr */
598 		t = getsval(y);
599 		pfa = makedfa(t, mode);
600 		i = (*mf)(pfa, s);
601 		tempfree(y);
602 	}
603 	tempfree(x);
604 	if (n == MATCHFCN) {
605 		int start = patbeg - s + 1;
606 		if (patlen < 0)
607 			start = 0;
608 		setfval(rstartloc, (Awkfloat) start);
609 		setfval(rlengthloc, (Awkfloat) patlen);
610 		x = gettemp();
611 		x->tval = NUM;
612 		x->fval = start;
613 		return x;
614 	} else if ((n == MATCH && i == 1) || (n == NOTMATCH && i == 0))
615 		return(True);
616 	else
617 		return(False);
618 }
619 
620 
621 Cell *boolop(Node **a, int n)	/* a[0] || a[1], a[0] && a[1], !a[0] */
622 {
623 	Cell *x, *y;
624 	int i;
625 
626 	x = execute(a[0]);
627 	i = istrue(x);
628 	tempfree(x);
629 	switch (n) {
630 	case BOR:
631 		if (i) return(True);
632 		y = execute(a[1]);
633 		i = istrue(y);
634 		tempfree(y);
635 		if (i) return(True);
636 		else return(False);
637 	case AND:
638 		if ( !i ) return(False);
639 		y = execute(a[1]);
640 		i = istrue(y);
641 		tempfree(y);
642 		if (i) return(True);
643 		else return(False);
644 	case NOT:
645 		if (i) return(False);
646 		else return(True);
647 	default:	/* can't happen */
648 		FATAL("unknown boolean operator %d", n);
649 	}
650 	return 0;	/*NOTREACHED*/
651 }
652 
653 Cell *relop(Node **a, int n)	/* a[0 < a[1], etc. */
654 {
655 	int i;
656 	Cell *x, *y;
657 	Awkfloat j;
658 
659 	x = execute(a[0]);
660 	y = execute(a[1]);
661 	if (x->tval&NUM && y->tval&NUM) {
662 		j = x->fval - y->fval;
663 		i = j<0? -1: (j>0? 1: 0);
664 	} else {
665 		i = strcmp(getsval(x), getsval(y));
666 	}
667 	tempfree(x);
668 	tempfree(y);
669 	switch (n) {
670 	case LT:	if (i<0) return(True);
671 			else return(False);
672 	case LE:	if (i<=0) return(True);
673 			else return(False);
674 	case NE:	if (i!=0) return(True);
675 			else return(False);
676 	case EQ:	if (i == 0) return(True);
677 			else return(False);
678 	case GE:	if (i>=0) return(True);
679 			else return(False);
680 	case GT:	if (i>0) return(True);
681 			else return(False);
682 	default:	/* can't happen */
683 		FATAL("unknown relational operator %d", n);
684 	}
685 	return 0;	/*NOTREACHED*/
686 }
687 
688 void tfree(Cell *a)	/* free a tempcell */
689 {
690 	if (freeable(a)) {
691 		DPRINTF("freeing %s %s %o\n", NN(a->nval), NN(a->sval), a->tval);
692 		xfree(a->sval);
693 	}
694 	if (a == tmps)
695 		FATAL("tempcell list is curdled");
696 	a->cnext = tmps;
697 	tmps = a;
698 }
699 
700 Cell *gettemp(void)	/* get a tempcell */
701 {	int i;
702 	Cell *x;
703 
704 	if (!tmps) {
705 		tmps = (Cell *) calloc(100, sizeof(*tmps));
706 		if (!tmps)
707 			FATAL("out of space for temporaries");
708 		for (i = 1; i < 100; i++)
709 			tmps[i-1].cnext = &tmps[i];
710 		tmps[i-1].cnext = NULL;
711 	}
712 	x = tmps;
713 	tmps = x->cnext;
714 	*x = tempcell;
715 	return(x);
716 }
717 
718 Cell *indirect(Node **a, int n)	/* $( a[0] ) */
719 {
720 	Awkfloat val;
721 	Cell *x;
722 	int m;
723 	char *s;
724 
725 	x = execute(a[0]);
726 	val = getfval(x);	/* freebsd: defend against super large field numbers */
727 	if ((Awkfloat)INT_MAX < val)
728 		FATAL("trying to access out of range field %s", x->nval);
729 	m = (int) val;
730 	if (m == 0 && !is_number(s = getsval(x), NULL))	/* suspicion! */
731 		FATAL("illegal field $(%s), name \"%s\"", s, x->nval);
732 		/* BUG: can x->nval ever be null??? */
733 	tempfree(x);
734 	x = fieldadr(m);
735 	x->ctype = OCELL;	/* BUG?  why are these needed? */
736 	x->csub = CFLD;
737 	return(x);
738 }
739 
740 Cell *substr(Node **a, int nnn)		/* substr(a[0], a[1], a[2]) */
741 {
742 	int k, m, n;
743 	char *s;
744 	int temp;
745 	Cell *x, *y, *z = NULL;
746 
747 	x = execute(a[0]);
748 	y = execute(a[1]);
749 	if (a[2] != NULL)
750 		z = execute(a[2]);
751 	s = getsval(x);
752 	k = strlen(s) + 1;
753 	if (k <= 1) {
754 		tempfree(x);
755 		tempfree(y);
756 		if (a[2] != NULL) {
757 			tempfree(z);
758 		}
759 		x = gettemp();
760 		setsval(x, "");
761 		return(x);
762 	}
763 	m = (int) getfval(y);
764 	if (m <= 0)
765 		m = 1;
766 	else if (m > k)
767 		m = k;
768 	tempfree(y);
769 	if (a[2] != NULL) {
770 		n = (int) getfval(z);
771 		tempfree(z);
772 	} else
773 		n = k - 1;
774 	if (n < 0)
775 		n = 0;
776 	else if (n > k - m)
777 		n = k - m;
778 	DPRINTF("substr: m=%d, n=%d, s=%s\n", m, n, s);
779 	y = gettemp();
780 	temp = s[n+m-1];	/* with thanks to John Linderman */
781 	s[n+m-1] = '\0';
782 	setsval(y, s + m - 1);
783 	s[n+m-1] = temp;
784 	tempfree(x);
785 	return(y);
786 }
787 
788 Cell *sindex(Node **a, int nnn)		/* index(a[0], a[1]) */
789 {
790 	Cell *x, *y, *z;
791 	char *s1, *s2, *p1, *p2, *q;
792 	Awkfloat v = 0.0;
793 
794 	x = execute(a[0]);
795 	s1 = getsval(x);
796 	y = execute(a[1]);
797 	s2 = getsval(y);
798 
799 	z = gettemp();
800 	for (p1 = s1; *p1 != '\0'; p1++) {
801 		for (q = p1, p2 = s2; *p2 != '\0' && *q == *p2; q++, p2++)
802 			continue;
803 		if (*p2 == '\0') {
804 			v = (Awkfloat) (p1 - s1 + 1);	/* origin 1 */
805 			break;
806 		}
807 	}
808 	tempfree(x);
809 	tempfree(y);
810 	setfval(z, v);
811 	return(z);
812 }
813 
814 #define	MAXNUMSIZE	50
815 
816 int format(char **pbuf, int *pbufsize, const char *s, Node *a)	/* printf-like conversions */
817 {
818 	char *fmt;
819 	char *p, *t;
820 	const char *os;
821 	Cell *x;
822 	int flag = 0, n;
823 	int fmtwd; /* format width */
824 	int fmtsz = recsize;
825 	char *buf = *pbuf;
826 	int bufsize = *pbufsize;
827 #define FMTSZ(a)   (fmtsz - ((a) - fmt))
828 #define BUFSZ(a)   (bufsize - ((a) - buf))
829 
830 	static bool first = true;
831 	static bool have_a_format = false;
832 
833 	if (first) {
834 		char xbuf[100];
835 
836 		snprintf(xbuf, sizeof(xbuf), "%a", 42.0);
837 		have_a_format = (strcmp(xbuf, "0x1.5p+5") == 0);
838 		first = false;
839 	}
840 
841 	os = s;
842 	p = buf;
843 	if ((fmt = (char *) malloc(fmtsz)) == NULL)
844 		FATAL("out of memory in format()");
845 	while (*s) {
846 		adjbuf(&buf, &bufsize, MAXNUMSIZE+1+p-buf, recsize, &p, "format1");
847 		if (*s != '%') {
848 			*p++ = *s++;
849 			continue;
850 		}
851 		if (*(s+1) == '%') {
852 			*p++ = '%';
853 			s += 2;
854 			continue;
855 		}
856 		/* have to be real careful in case this is a huge number, eg, %100000d */
857 		fmtwd = atoi(s+1);
858 		if (fmtwd < 0)
859 			fmtwd = -fmtwd;
860 		adjbuf(&buf, &bufsize, fmtwd+1+p-buf, recsize, &p, "format2");
861 		for (t = fmt; (*t++ = *s) != '\0'; s++) {
862 			if (!adjbuf(&fmt, &fmtsz, MAXNUMSIZE+1+t-fmt, recsize, &t, "format3"))
863 				FATAL("format item %.30s... ran format() out of memory", os);
864 			/* Ignore size specifiers */
865 			if (strchr("hjLlqtz", *s) != NULL) {	/* the ansi panoply */
866 				t--;
867 				continue;
868 			}
869 			if (isalpha((uschar)*s))
870 				break;
871 			if (*s == '$') {
872 				FATAL("'$' not permitted in awk formats");
873 			}
874 			if (*s == '*') {
875 				if (a == NULL) {
876 					FATAL("not enough args in printf(%s)", os);
877 				}
878 				x = execute(a);
879 				a = a->nnext;
880 				snprintf(t - 1, FMTSZ(t - 1),
881 				    "%d", fmtwd=(int) getfval(x));
882 				if (fmtwd < 0)
883 					fmtwd = -fmtwd;
884 				adjbuf(&buf, &bufsize, fmtwd+1+p-buf, recsize, &p, "format");
885 				t = fmt + strlen(fmt);
886 				tempfree(x);
887 			}
888 		}
889 		*t = '\0';
890 		if (fmtwd < 0)
891 			fmtwd = -fmtwd;
892 		adjbuf(&buf, &bufsize, fmtwd+1+p-buf, recsize, &p, "format4");
893 		switch (*s) {
894 		case 'a': case 'A':
895 			if (have_a_format)
896 				flag = *s;
897 			else
898 				flag = 'f';
899 			break;
900 		case 'f': case 'e': case 'g': case 'E': case 'G':
901 			flag = 'f';
902 			break;
903 		case 'd': case 'i': case 'o': case 'x': case 'X': case 'u':
904 			flag = (*s == 'd' || *s == 'i') ? 'd' : 'u';
905 			*(t-1) = 'j';
906 			*t = *s;
907 			*++t = '\0';
908 			break;
909 		case 's':
910 			flag = 's';
911 			break;
912 		case 'c':
913 			flag = 'c';
914 			break;
915 		default:
916 			WARNING("weird printf conversion %s", fmt);
917 			flag = '?';
918 			break;
919 		}
920 		if (a == NULL)
921 			FATAL("not enough args in printf(%s)", os);
922 		x = execute(a);
923 		a = a->nnext;
924 		n = MAXNUMSIZE;
925 		if (fmtwd > n)
926 			n = fmtwd;
927 		adjbuf(&buf, &bufsize, 1+n+p-buf, recsize, &p, "format5");
928 		switch (flag) {
929 		case '?':	snprintf(p, BUFSZ(p), "%s", fmt);	/* unknown, so dump it too */
930 			t = getsval(x);
931 			n = strlen(t);
932 			if (fmtwd > n)
933 				n = fmtwd;
934 			adjbuf(&buf, &bufsize, 1+strlen(p)+n+p-buf, recsize, &p, "format6");
935 			p += strlen(p);
936 			snprintf(p, BUFSZ(p), "%s", t);
937 			break;
938 		case 'a':
939 		case 'A':
940 		case 'f':	snprintf(p, BUFSZ(p), fmt, getfval(x)); break;
941 		case 'd':	snprintf(p, BUFSZ(p), fmt, (intmax_t) getfval(x)); break;
942 		case 'u':	snprintf(p, BUFSZ(p), fmt, (uintmax_t) getfval(x)); break;
943 		case 's':
944 			t = getsval(x);
945 			n = strlen(t);
946 			if (fmtwd > n)
947 				n = fmtwd;
948 			if (!adjbuf(&buf, &bufsize, 1+n+p-buf, recsize, &p, "format7"))
949 				FATAL("huge string/format (%d chars) in printf %.30s... ran format() out of memory", n, t);
950 			snprintf(p, BUFSZ(p), fmt, t);
951 			break;
952 		case 'c':
953 			if (isnum(x)) {
954 				if ((int)getfval(x))
955 					snprintf(p, BUFSZ(p), fmt, (int) getfval(x));
956 				else {
957 					*p++ = '\0'; /* explicit null byte */
958 					*p = '\0';   /* next output will start here */
959 				}
960 			} else
961 				snprintf(p, BUFSZ(p), fmt, getsval(x)[0]);
962 			break;
963 		default:
964 			FATAL("can't happen: bad conversion %c in format()", flag);
965 		}
966 		tempfree(x);
967 		p += strlen(p);
968 		s++;
969 	}
970 	*p = '\0';
971 	free(fmt);
972 	for ( ; a; a = a->nnext)		/* evaluate any remaining args */
973 		execute(a);
974 	*pbuf = buf;
975 	*pbufsize = bufsize;
976 	return p - buf;
977 }
978 
979 Cell *awksprintf(Node **a, int n)		/* sprintf(a[0]) */
980 {
981 	Cell *x;
982 	Node *y;
983 	char *buf;
984 	int bufsz=3*recsize;
985 
986 	if ((buf = (char *) malloc(bufsz)) == NULL)
987 		FATAL("out of memory in awksprintf");
988 	y = a[0]->nnext;
989 	x = execute(a[0]);
990 	if (format(&buf, &bufsz, getsval(x), y) == -1)
991 		FATAL("sprintf string %.30s... too long.  can't happen.", buf);
992 	tempfree(x);
993 	x = gettemp();
994 	x->sval = buf;
995 	x->tval = STR;
996 	return(x);
997 }
998 
999 Cell *awkprintf(Node **a, int n)		/* printf */
1000 {	/* a[0] is list of args, starting with format string */
1001 	/* a[1] is redirection operator, a[2] is redirection file */
1002 	FILE *fp;
1003 	Cell *x;
1004 	Node *y;
1005 	char *buf;
1006 	int len;
1007 	int bufsz=3*recsize;
1008 
1009 	if ((buf = (char *) malloc(bufsz)) == NULL)
1010 		FATAL("out of memory in awkprintf");
1011 	y = a[0]->nnext;
1012 	x = execute(a[0]);
1013 	if ((len = format(&buf, &bufsz, getsval(x), y)) == -1)
1014 		FATAL("printf string %.30s... too long.  can't happen.", buf);
1015 	tempfree(x);
1016 	if (a[1] == NULL) {
1017 		/* fputs(buf, stdout); */
1018 		fwrite(buf, len, 1, stdout);
1019 		if (ferror(stdout))
1020 			FATAL("write error on stdout");
1021 	} else {
1022 		fp = redirect(ptoi(a[1]), a[2]);
1023 		/* fputs(buf, fp); */
1024 		fwrite(buf, len, 1, fp);
1025 		fflush(fp);
1026 		if (ferror(fp))
1027 			FATAL("write error on %s", filename(fp));
1028 	}
1029 	free(buf);
1030 	return(True);
1031 }
1032 
1033 Cell *arith(Node **a, int n)	/* a[0] + a[1], etc.  also -a[0] */
1034 {
1035 	Awkfloat i, j = 0;
1036 	double v;
1037 	Cell *x, *y, *z;
1038 
1039 	x = execute(a[0]);
1040 	i = getfval(x);
1041 	tempfree(x);
1042 	if (n != UMINUS && n != UPLUS) {
1043 		y = execute(a[1]);
1044 		j = getfval(y);
1045 		tempfree(y);
1046 	}
1047 	z = gettemp();
1048 	switch (n) {
1049 	case ADD:
1050 		i += j;
1051 		break;
1052 	case MINUS:
1053 		i -= j;
1054 		break;
1055 	case MULT:
1056 		i *= j;
1057 		break;
1058 	case DIVIDE:
1059 		if (j == 0)
1060 			FATAL("division by zero");
1061 		i /= j;
1062 		break;
1063 	case MOD:
1064 		if (j == 0)
1065 			FATAL("division by zero in mod");
1066 		modf(i/j, &v);
1067 		i = i - j * v;
1068 		break;
1069 	case UMINUS:
1070 		i = -i;
1071 		break;
1072 	case UPLUS: /* handled by getfval(), above */
1073 		break;
1074 	case POWER:
1075 		if (j >= 0 && modf(j, &v) == 0.0)	/* pos integer exponent */
1076 			i = ipow(i, (int) j);
1077                else {
1078 			errno = 0;
1079 			i = errcheck(pow(i, j), "pow");
1080                }
1081 		break;
1082 	default:	/* can't happen */
1083 		FATAL("illegal arithmetic operator %d", n);
1084 	}
1085 	setfval(z, i);
1086 	return(z);
1087 }
1088 
1089 double ipow(double x, int n)	/* x**n.  ought to be done by pow, but isn't always */
1090 {
1091 	double v;
1092 
1093 	if (n <= 0)
1094 		return 1;
1095 	v = ipow(x, n/2);
1096 	if (n % 2 == 0)
1097 		return v * v;
1098 	else
1099 		return x * v * v;
1100 }
1101 
1102 Cell *incrdecr(Node **a, int n)		/* a[0]++, etc. */
1103 {
1104 	Cell *x, *z;
1105 	int k;
1106 	Awkfloat xf;
1107 
1108 	x = execute(a[0]);
1109 	xf = getfval(x);
1110 	k = (n == PREINCR || n == POSTINCR) ? 1 : -1;
1111 	if (n == PREINCR || n == PREDECR) {
1112 		setfval(x, xf + k);
1113 		return(x);
1114 	}
1115 	z = gettemp();
1116 	setfval(z, xf);
1117 	setfval(x, xf + k);
1118 	tempfree(x);
1119 	return(z);
1120 }
1121 
1122 Cell *assign(Node **a, int n)	/* a[0] = a[1], a[0] += a[1], etc. */
1123 {		/* this is subtle; don't muck with it. */
1124 	Cell *x, *y;
1125 	Awkfloat xf, yf;
1126 	double v;
1127 
1128 	y = execute(a[1]);
1129 	x = execute(a[0]);
1130 	if (n == ASSIGN) {	/* ordinary assignment */
1131 		if (x == y && !(x->tval & (FLD|REC)) && x != nfloc)
1132 			;	/* self-assignment: leave alone unless it's a field or NF */
1133 		else if ((y->tval & (STR|NUM)) == (STR|NUM)) {
1134 			setsval(x, getsval(y));
1135 			x->fval = getfval(y);
1136 			x->tval |= NUM;
1137 		}
1138 		else if (isstr(y))
1139 			setsval(x, getsval(y));
1140 		else if (isnum(y))
1141 			setfval(x, getfval(y));
1142 		else
1143 			funnyvar(y, "read value of");
1144 		tempfree(y);
1145 		return(x);
1146 	}
1147 	xf = getfval(x);
1148 	yf = getfval(y);
1149 	switch (n) {
1150 	case ADDEQ:
1151 		xf += yf;
1152 		break;
1153 	case SUBEQ:
1154 		xf -= yf;
1155 		break;
1156 	case MULTEQ:
1157 		xf *= yf;
1158 		break;
1159 	case DIVEQ:
1160 		if (yf == 0)
1161 			FATAL("division by zero in /=");
1162 		xf /= yf;
1163 		break;
1164 	case MODEQ:
1165 		if (yf == 0)
1166 			FATAL("division by zero in %%=");
1167 		modf(xf/yf, &v);
1168 		xf = xf - yf * v;
1169 		break;
1170 	case POWEQ:
1171 		if (yf >= 0 && modf(yf, &v) == 0.0)	/* pos integer exponent */
1172 			xf = ipow(xf, (int) yf);
1173                else {
1174 			errno = 0;
1175 			xf = errcheck(pow(xf, yf), "pow");
1176                }
1177 		break;
1178 	default:
1179 		FATAL("illegal assignment operator %d", n);
1180 		break;
1181 	}
1182 	tempfree(y);
1183 	setfval(x, xf);
1184 	return(x);
1185 }
1186 
1187 Cell *cat(Node **a, int q)	/* a[0] cat a[1] */
1188 {
1189 	Cell *x, *y, *z;
1190 	int n1, n2;
1191 	char *s = NULL;
1192 	int ssz = 0;
1193 
1194 	x = execute(a[0]);
1195 	n1 = strlen(getsval(x));
1196 	adjbuf(&s, &ssz, n1, recsize, 0, "cat1");
1197 	memcpy(s, x->sval, n1);
1198 
1199 	y = execute(a[1]);
1200 	n2 = strlen(getsval(y));
1201 	adjbuf(&s, &ssz, n1 + n2 + 1, recsize, 0, "cat2");
1202 	memcpy(s + n1, y->sval, n2);
1203 	s[n1 + n2] = '\0';
1204 
1205 	tempfree(x);
1206 	tempfree(y);
1207 
1208 	z = gettemp();
1209 	z->sval = s;
1210 	z->tval = STR;
1211 
1212 	return(z);
1213 }
1214 
1215 Cell *pastat(Node **a, int n)	/* a[0] { a[1] } */
1216 {
1217 	Cell *x;
1218 
1219 	if (a[0] == NULL)
1220 		x = execute(a[1]);
1221 	else {
1222 		x = execute(a[0]);
1223 		if (istrue(x)) {
1224 			tempfree(x);
1225 			x = execute(a[1]);
1226 		}
1227 	}
1228 	return x;
1229 }
1230 
1231 Cell *dopa2(Node **a, int n)	/* a[0], a[1] { a[2] } */
1232 {
1233 	Cell *x;
1234 	int pair;
1235 
1236 	pair = ptoi(a[3]);
1237 	if (pairstack[pair] == 0) {
1238 		x = execute(a[0]);
1239 		if (istrue(x))
1240 			pairstack[pair] = 1;
1241 		tempfree(x);
1242 	}
1243 	if (pairstack[pair] == 1) {
1244 		x = execute(a[1]);
1245 		if (istrue(x))
1246 			pairstack[pair] = 0;
1247 		tempfree(x);
1248 		x = execute(a[2]);
1249 		return(x);
1250 	}
1251 	return(False);
1252 }
1253 
1254 Cell *split(Node **a, int nnn)	/* split(a[0], a[1], a[2]); a[3] is type */
1255 {
1256 	Cell *x = NULL, *y, *ap;
1257 	const char *s, *origs, *t;
1258 	const char *fs = NULL;
1259 	char *origfs = NULL;
1260 	int sep;
1261 	char temp, num[50];
1262 	int n, tempstat, arg3type;
1263 	double result;
1264 
1265 	y = execute(a[0]);	/* source string */
1266 	origs = s = strdup(getsval(y));
1267 	arg3type = ptoi(a[3]);
1268 	if (a[2] == NULL)		/* fs string */
1269 		fs = getsval(fsloc);
1270 	else if (arg3type == STRING) {	/* split(str,arr,"string") */
1271 		x = execute(a[2]);
1272 		fs = origfs = strdup(getsval(x));
1273 		tempfree(x);
1274 	} else if (arg3type == REGEXPR)
1275 		fs = "(regexpr)";	/* split(str,arr,/regexpr/) */
1276 	else
1277 		FATAL("illegal type of split");
1278 	sep = *fs;
1279 	ap = execute(a[1]);	/* array name */
1280 	freesymtab(ap);
1281 	DPRINTF("split: s=|%s|, a=%s, sep=|%s|\n", s, NN(ap->nval), fs);
1282 	ap->tval &= ~STR;
1283 	ap->tval |= ARR;
1284 	ap->sval = (char *) makesymtab(NSYMTAB);
1285 
1286 	n = 0;
1287         if (arg3type == REGEXPR && strlen((char*)((fa*)a[2])->restr) == 0) {
1288 		/* split(s, a, //); have to arrange that it looks like empty sep */
1289 		arg3type = 0;
1290 		fs = "";
1291 		sep = 0;
1292 	}
1293 	if (*s != '\0' && (strlen(fs) > 1 || arg3type == REGEXPR)) {	/* reg expr */
1294 		fa *pfa;
1295 		if (arg3type == REGEXPR) {	/* it's ready already */
1296 			pfa = (fa *) a[2];
1297 		} else {
1298 			pfa = makedfa(fs, 1);
1299 		}
1300 		if (nematch(pfa,s)) {
1301 			tempstat = pfa->initstat;
1302 			pfa->initstat = 2;
1303 			do {
1304 				n++;
1305 				snprintf(num, sizeof(num), "%d", n);
1306 				temp = *patbeg;
1307 				setptr(patbeg, '\0');
1308 				if (is_number(s, & result))
1309 					setsymtab(num, s, result, STR|NUM, (Array *) ap->sval);
1310 				else
1311 					setsymtab(num, s, 0.0, STR, (Array *) ap->sval);
1312 				setptr(patbeg, temp);
1313 				s = patbeg + patlen;
1314 				if (*(patbeg+patlen-1) == '\0' || *s == '\0') {
1315 					n++;
1316 					snprintf(num, sizeof(num), "%d", n);
1317 					setsymtab(num, "", 0.0, STR, (Array *) ap->sval);
1318 					pfa->initstat = tempstat;
1319 					goto spdone;
1320 				}
1321 			} while (nematch(pfa,s));
1322 			pfa->initstat = tempstat; 	/* bwk: has to be here to reset */
1323 							/* cf gsub and refldbld */
1324 		}
1325 		n++;
1326 		snprintf(num, sizeof(num), "%d", n);
1327 		if (is_number(s, & result))
1328 			setsymtab(num, s, result, STR|NUM, (Array *) ap->sval);
1329 		else
1330 			setsymtab(num, s, 0.0, STR, (Array *) ap->sval);
1331   spdone:
1332 		pfa = NULL;
1333 	} else if (sep == ' ') {
1334 		for (n = 0; ; ) {
1335 #define ISWS(c)	((c) == ' ' || (c) == '\t' || (c) == '\n')
1336 			while (ISWS(*s))
1337 				s++;
1338 			if (*s == '\0')
1339 				break;
1340 			n++;
1341 			t = s;
1342 			do
1343 				s++;
1344 			while (*s != '\0' && !ISWS(*s));
1345 			temp = *s;
1346 			setptr(s, '\0');
1347 			snprintf(num, sizeof(num), "%d", n);
1348 			if (is_number(t, & result))
1349 				setsymtab(num, t, result, STR|NUM, (Array *) ap->sval);
1350 			else
1351 				setsymtab(num, t, 0.0, STR, (Array *) ap->sval);
1352 			setptr(s, temp);
1353 			if (*s != '\0')
1354 				s++;
1355 		}
1356 	} else if (sep == 0) {	/* new: split(s, a, "") => 1 char/elem */
1357 		for (n = 0; *s != '\0'; s++) {
1358 			char buf[2];
1359 			n++;
1360 			snprintf(num, sizeof(num), "%d", n);
1361 			buf[0] = *s;
1362 			buf[1] = '\0';
1363 			if (isdigit((uschar)buf[0]))
1364 				setsymtab(num, buf, atof(buf), STR|NUM, (Array *) ap->sval);
1365 			else
1366 				setsymtab(num, buf, 0.0, STR, (Array *) ap->sval);
1367 		}
1368 	} else if (*s != '\0') {
1369 		for (;;) {
1370 			n++;
1371 			t = s;
1372 			while (*s != sep && *s != '\n' && *s != '\0')
1373 				s++;
1374 			temp = *s;
1375 			setptr(s, '\0');
1376 			snprintf(num, sizeof(num), "%d", n);
1377 			if (is_number(t, & result))
1378 				setsymtab(num, t, result, STR|NUM, (Array *) ap->sval);
1379 			else
1380 				setsymtab(num, t, 0.0, STR, (Array *) ap->sval);
1381 			setptr(s, temp);
1382 			if (*s++ == '\0')
1383 				break;
1384 		}
1385 	}
1386 	tempfree(ap);
1387 	tempfree(y);
1388 	xfree(origs);
1389 	xfree(origfs);
1390 	x = gettemp();
1391 	x->tval = NUM;
1392 	x->fval = n;
1393 	return(x);
1394 }
1395 
1396 Cell *condexpr(Node **a, int n)	/* a[0] ? a[1] : a[2] */
1397 {
1398 	Cell *x;
1399 
1400 	x = execute(a[0]);
1401 	if (istrue(x)) {
1402 		tempfree(x);
1403 		x = execute(a[1]);
1404 	} else {
1405 		tempfree(x);
1406 		x = execute(a[2]);
1407 	}
1408 	return(x);
1409 }
1410 
1411 Cell *ifstat(Node **a, int n)	/* if (a[0]) a[1]; else a[2] */
1412 {
1413 	Cell *x;
1414 
1415 	x = execute(a[0]);
1416 	if (istrue(x)) {
1417 		tempfree(x);
1418 		x = execute(a[1]);
1419 	} else if (a[2] != NULL) {
1420 		tempfree(x);
1421 		x = execute(a[2]);
1422 	}
1423 	return(x);
1424 }
1425 
1426 Cell *whilestat(Node **a, int n)	/* while (a[0]) a[1] */
1427 {
1428 	Cell *x;
1429 
1430 	for (;;) {
1431 		x = execute(a[0]);
1432 		if (!istrue(x))
1433 			return(x);
1434 		tempfree(x);
1435 		x = execute(a[1]);
1436 		if (isbreak(x)) {
1437 			x = True;
1438 			return(x);
1439 		}
1440 		if (isnext(x) || isexit(x) || isret(x))
1441 			return(x);
1442 		tempfree(x);
1443 	}
1444 }
1445 
1446 Cell *dostat(Node **a, int n)	/* do a[0]; while(a[1]) */
1447 {
1448 	Cell *x;
1449 
1450 	for (;;) {
1451 		x = execute(a[0]);
1452 		if (isbreak(x))
1453 			return True;
1454 		if (isnext(x) || isexit(x) || isret(x))
1455 			return(x);
1456 		tempfree(x);
1457 		x = execute(a[1]);
1458 		if (!istrue(x))
1459 			return(x);
1460 		tempfree(x);
1461 	}
1462 }
1463 
1464 Cell *forstat(Node **a, int n)	/* for (a[0]; a[1]; a[2]) a[3] */
1465 {
1466 	Cell *x;
1467 
1468 	x = execute(a[0]);
1469 	tempfree(x);
1470 	for (;;) {
1471 		if (a[1]!=NULL) {
1472 			x = execute(a[1]);
1473 			if (!istrue(x)) return(x);
1474 			else tempfree(x);
1475 		}
1476 		x = execute(a[3]);
1477 		if (isbreak(x))		/* turn off break */
1478 			return True;
1479 		if (isnext(x) || isexit(x) || isret(x))
1480 			return(x);
1481 		tempfree(x);
1482 		x = execute(a[2]);
1483 		tempfree(x);
1484 	}
1485 }
1486 
1487 Cell *instat(Node **a, int n)	/* for (a[0] in a[1]) a[2] */
1488 {
1489 	Cell *x, *vp, *arrayp, *cp, *ncp;
1490 	Array *tp;
1491 	int i;
1492 
1493 	vp = execute(a[0]);
1494 	arrayp = execute(a[1]);
1495 	if (!isarr(arrayp)) {
1496 		return True;
1497 	}
1498 	tp = (Array *) arrayp->sval;
1499 	tempfree(arrayp);
1500 	for (i = 0; i < tp->size; i++) {	/* this routine knows too much */
1501 		for (cp = tp->tab[i]; cp != NULL; cp = ncp) {
1502 			setsval(vp, cp->nval);
1503 			ncp = cp->cnext;
1504 			x = execute(a[2]);
1505 			if (isbreak(x)) {
1506 				tempfree(vp);
1507 				return True;
1508 			}
1509 			if (isnext(x) || isexit(x) || isret(x)) {
1510 				tempfree(vp);
1511 				return(x);
1512 			}
1513 			tempfree(x);
1514 		}
1515 	}
1516 	return True;
1517 }
1518 
1519 static char *nawk_convert(const char *s, int (*fun_c)(int),
1520     wint_t (*fun_wc)(wint_t))
1521 {
1522 	char *buf      = NULL;
1523 	char *pbuf     = NULL;
1524 	const char *ps = NULL;
1525 	size_t n       = 0;
1526 	wchar_t wc;
1527 	size_t sz = MB_CUR_MAX;
1528 
1529 	if (sz == 1) {
1530 		buf = tostring(s);
1531 
1532 		for (pbuf = buf; *pbuf; pbuf++)
1533 			*pbuf = fun_c((uschar)*pbuf);
1534 
1535 		return buf;
1536 	} else {
1537 		/* upper/lower character may be shorter/longer */
1538 		buf = tostringN(s, strlen(s) * sz + 1);
1539 
1540 		(void) mbtowc(NULL, NULL, 0);	/* reset internal state */
1541 		/*
1542 		 * Reset internal state here too.
1543 		 * Assign result to avoid a compiler warning. (Casting to void
1544 		 * doesn't work.)
1545 		 * Increment said variable to avoid a different warning.
1546 		 */
1547 		int unused = wctomb(NULL, L'\0');
1548 		unused++;
1549 
1550 		ps   = s;
1551 		pbuf = buf;
1552 		while (n = mbtowc(&wc, ps, sz),
1553 		       n > 0 && n != (size_t)-1 && n != (size_t)-2)
1554 		{
1555 			ps += n;
1556 
1557 			n = wctomb(pbuf, fun_wc(wc));
1558 			if (n == (size_t)-1)
1559 				FATAL("illegal wide character %s", s);
1560 
1561 			pbuf += n;
1562 		}
1563 
1564 		*pbuf = '\0';
1565 
1566 		if (n)
1567 			FATAL("illegal byte sequence %s", s);
1568 
1569 		return buf;
1570 	}
1571 }
1572 
1573 #ifdef __DJGPP__
1574 static wint_t towupper(wint_t wc)
1575 {
1576 	if (wc >= 0 && wc < 256)
1577 		return toupper(wc & 0xFF);
1578 
1579 	return wc;
1580 }
1581 
1582 static wint_t towlower(wint_t wc)
1583 {
1584 	if (wc >= 0 && wc < 256)
1585 		return tolower(wc & 0xFF);
1586 
1587 	return wc;
1588 }
1589 #endif
1590 
1591 static char *nawk_toupper(const char *s)
1592 {
1593 	return nawk_convert(s, toupper, towupper);
1594 }
1595 
1596 static char *nawk_tolower(const char *s)
1597 {
1598 	return nawk_convert(s, tolower, towlower);
1599 }
1600 
1601 Cell *bltin(Node **a, int n)	/* builtin functions. a[0] is type, a[1] is arg list */
1602 {
1603 	Cell *x, *y;
1604 	Awkfloat u;
1605 	int t, sz;
1606 	Awkfloat tmp;
1607 	char *buf, *fmt;
1608 	Node *nextarg;
1609 	FILE *fp;
1610 	int status = 0;
1611 	time_t tv;
1612 	struct tm *tm;
1613 
1614 	t = ptoi(a[0]);
1615 	x = execute(a[1]);
1616 	nextarg = a[1]->nnext;
1617 	switch (t) {
1618 	case FLENGTH:
1619 		if (isarr(x))
1620 			u = ((Array *) x->sval)->nelem;	/* GROT.  should be function*/
1621 		else
1622 			u = strlen(getsval(x));
1623 		break;
1624 	case FLOG:
1625 		errno = 0;
1626 		u = errcheck(log(getfval(x)), "log");
1627 		break;
1628 	case FINT:
1629 		modf(getfval(x), &u); break;
1630 	case FEXP:
1631 		errno = 0;
1632 		u = errcheck(exp(getfval(x)), "exp");
1633 		break;
1634 	case FSQRT:
1635 		errno = 0;
1636 		u = errcheck(sqrt(getfval(x)), "sqrt");
1637 		break;
1638 	case FSIN:
1639 		u = sin(getfval(x)); break;
1640 	case FCOS:
1641 		u = cos(getfval(x)); break;
1642 	case FATAN:
1643 		if (nextarg == NULL) {
1644 			WARNING("atan2 requires two arguments; returning 1.0");
1645 			u = 1.0;
1646 		} else {
1647 			y = execute(a[1]->nnext);
1648 			u = atan2(getfval(x), getfval(y));
1649 			tempfree(y);
1650 			nextarg = nextarg->nnext;
1651 		}
1652 		break;
1653 	case FCOMPL:
1654 		u = ~((int)getfval(x));
1655 		break;
1656 	case FAND:
1657 		if (nextarg == 0) {
1658 			WARNING("and requires two arguments; returning 0");
1659 			u = 0;
1660 			break;
1661 		}
1662 		y = execute(a[1]->nnext);
1663 		u = ((int)getfval(x)) & ((int)getfval(y));
1664 		tempfree(y);
1665 		nextarg = nextarg->nnext;
1666 		break;
1667 	case FFOR:
1668 		if (nextarg == 0) {
1669 			WARNING("or requires two arguments; returning 0");
1670 			u = 0;
1671 			break;
1672 		}
1673 		y = execute(a[1]->nnext);
1674 		u = ((int)getfval(x)) | ((int)getfval(y));
1675 		tempfree(y);
1676 		nextarg = nextarg->nnext;
1677 		break;
1678 	case FXOR:
1679 		if (nextarg == 0) {
1680 			WARNING("xor requires two arguments; returning 0");
1681 			u = 0;
1682 			break;
1683 		}
1684 		y = execute(a[1]->nnext);
1685 		u = ((int)getfval(x)) ^ ((int)getfval(y));
1686 		tempfree(y);
1687 		nextarg = nextarg->nnext;
1688 		break;
1689 	case FLSHIFT:
1690 		if (nextarg == 0) {
1691 			WARNING("lshift requires two arguments; returning 0");
1692 			u = 0;
1693 			break;
1694 		}
1695 		y = execute(a[1]->nnext);
1696 		u = ((int)getfval(x)) << ((int)getfval(y));
1697 		tempfree(y);
1698 		nextarg = nextarg->nnext;
1699 		break;
1700 	case FRSHIFT:
1701 		if (nextarg == 0) {
1702 			WARNING("rshift requires two arguments; returning 0");
1703 			u = 0;
1704 			break;
1705 		}
1706 		y = execute(a[1]->nnext);
1707 		u = ((int)getfval(x)) >> ((int)getfval(y));
1708 		tempfree(y);
1709 		nextarg = nextarg->nnext;
1710 		break;
1711 	case FSYSTEM:
1712 		fflush(stdout);		/* in case something is buffered already */
1713 		status = system(getsval(x));
1714 		u = status;
1715 		if (status != -1) {
1716 			if (WIFEXITED(status)) {
1717 				u = WEXITSTATUS(status);
1718 			} else if (WIFSIGNALED(status)) {
1719 				u = WTERMSIG(status) + 256;
1720 #ifdef WCOREDUMP
1721 				if (WCOREDUMP(status))
1722 					u += 256;
1723 #endif
1724 			} else	/* something else?!? */
1725 				u = 0;
1726 		}
1727 		break;
1728 	case FRAND:
1729 		/* random() returns numbers in [0..2^31-1]
1730 		 * in order to get a number in [0, 1), divide it by 2^31
1731 		 */
1732 		u = (Awkfloat) random() / (0x7fffffffL + 0x1UL);
1733 		break;
1734 	case FSRAND:
1735 		if (isrec(x))	/* no argument provided */
1736 			u = time((time_t *)0);
1737 		else
1738 			u = getfval(x);
1739 		tmp = u;
1740 		srandom((unsigned long) u);
1741 		u = srand_seed;
1742 		srand_seed = tmp;
1743 		break;
1744 	case FTOUPPER:
1745 	case FTOLOWER:
1746 		if (t == FTOUPPER)
1747 			buf = nawk_toupper(getsval(x));
1748 		else
1749 			buf = nawk_tolower(getsval(x));
1750 		tempfree(x);
1751 		x = gettemp();
1752 		setsval(x, buf);
1753 		free(buf);
1754 		return x;
1755 	case FFLUSH:
1756 		if (isrec(x) || strlen(getsval(x)) == 0) {
1757 			flush_all();	/* fflush() or fflush("") -> all */
1758 			u = 0;
1759 		} else if ((fp = openfile(FFLUSH, getsval(x), NULL)) == NULL)
1760 			u = EOF;
1761 		else
1762 			u = fflush(fp);
1763 		break;
1764 	case FSYSTIME:
1765 		u = time((time_t *) 0);
1766 		break;
1767 	case FSTRFTIME:
1768 		/* strftime([format [,timestamp]]) */
1769 		if (nextarg) {
1770 			y = execute(nextarg);
1771 			nextarg = nextarg->nnext;
1772 			tv = (time_t) getfval(y);
1773 			tempfree(y);
1774 		} else
1775 			tv = time((time_t *) 0);
1776 		tm = localtime(&tv);
1777 		if (tm == NULL)
1778 			FATAL("bad time %ld", (long)tv);
1779 
1780 		if (isrec(x)) {
1781 			/* format argument not provided, use default */
1782 			fmt = tostring("%a %b %d %H:%M:%S %Z %Y");
1783 		} else
1784 			fmt = tostring(getsval(x));
1785 
1786 		sz = 32;
1787 		buf = NULL;
1788 		do {
1789 			if ((buf = realloc(buf, (sz *= 2))) == NULL)
1790 				FATAL("out of memory in strftime");
1791 		} while (strftime(buf, sz, fmt, tm) == 0 && fmt[0] != '\0');
1792 
1793 		y = gettemp();
1794 		setsval(y, buf);
1795 		free(fmt);
1796 		free(buf);
1797 
1798 		return y;
1799 	default:	/* can't happen */
1800 		FATAL("illegal function type %d", t);
1801 		break;
1802 	}
1803 	tempfree(x);
1804 	x = gettemp();
1805 	setfval(x, u);
1806 	if (nextarg != NULL) {
1807 		WARNING("warning: function has too many arguments");
1808 		for ( ; nextarg; nextarg = nextarg->nnext)
1809 			execute(nextarg);
1810 	}
1811 	return(x);
1812 }
1813 
1814 Cell *printstat(Node **a, int n)	/* print a[0] */
1815 {
1816 	Node *x;
1817 	Cell *y;
1818 	FILE *fp;
1819 
1820 	if (a[1] == NULL)	/* a[1] is redirection operator, a[2] is file */
1821 		fp = stdout;
1822 	else
1823 		fp = redirect(ptoi(a[1]), a[2]);
1824 	for (x = a[0]; x != NULL; x = x->nnext) {
1825 		y = execute(x);
1826 		fputs(getpssval(y), fp);
1827 		tempfree(y);
1828 		if (x->nnext == NULL)
1829 			fputs(getsval(orsloc), fp);
1830 		else
1831 			fputs(getsval(ofsloc), fp);
1832 	}
1833 	if (a[1] != NULL)
1834 		fflush(fp);
1835 	if (ferror(fp))
1836 		FATAL("write error on %s", filename(fp));
1837 	return(True);
1838 }
1839 
1840 Cell *nullproc(Node **a, int n)
1841 {
1842 	return 0;
1843 }
1844 
1845 
1846 FILE *redirect(int a, Node *b)	/* set up all i/o redirections */
1847 {
1848 	FILE *fp;
1849 	Cell *x;
1850 	char *fname;
1851 
1852 	x = execute(b);
1853 	fname = getsval(x);
1854 	fp = openfile(a, fname, NULL);
1855 	if (fp == NULL)
1856 		FATAL("can't open file %s", fname);
1857 	tempfree(x);
1858 	return fp;
1859 }
1860 
1861 struct files {
1862 	FILE	*fp;
1863 	const char	*fname;
1864 	int	mode;	/* '|', 'a', 'w' => LE/LT, GT */
1865 } *files;
1866 
1867 size_t nfiles;
1868 
1869 static void stdinit(void)	/* in case stdin, etc., are not constants */
1870 {
1871 	nfiles = FOPEN_MAX;
1872 	files = (struct files *) calloc(nfiles, sizeof(*files));
1873 	if (files == NULL)
1874 		FATAL("can't allocate file memory for %zu files", nfiles);
1875         files[0].fp = stdin;
1876 	files[0].fname = "/dev/stdin";
1877 	files[0].mode = LT;
1878         files[1].fp = stdout;
1879 	files[1].fname = "/dev/stdout";
1880 	files[1].mode = GT;
1881         files[2].fp = stderr;
1882 	files[2].fname = "/dev/stderr";
1883 	files[2].mode = GT;
1884 }
1885 
1886 FILE *openfile(int a, const char *us, bool *pnewflag)
1887 {
1888 	const char *s = us;
1889 	size_t i;
1890 	int m;
1891 	FILE *fp = NULL;
1892 
1893 	if (*s == '\0')
1894 		FATAL("null file name in print or getline");
1895 	for (i = 0; i < nfiles; i++)
1896 		if (files[i].fname && strcmp(s, files[i].fname) == 0 &&
1897 		    (a == files[i].mode || (a==APPEND && files[i].mode==GT) ||
1898 		     a == FFLUSH)) {
1899 			if (pnewflag)
1900 				*pnewflag = false;
1901 			return files[i].fp;
1902 		}
1903 	if (a == FFLUSH)	/* didn't find it, so don't create it! */
1904 		return NULL;
1905 
1906 	for (i = 0; i < nfiles; i++)
1907 		if (files[i].fp == NULL)
1908 			break;
1909 	if (i >= nfiles) {
1910 		struct files *nf;
1911 		size_t nnf = nfiles + FOPEN_MAX;
1912 		nf = (struct files *) realloc(files, nnf * sizeof(*nf));
1913 		if (nf == NULL)
1914 			FATAL("cannot grow files for %s and %zu files", s, nnf);
1915 		memset(&nf[nfiles], 0, FOPEN_MAX * sizeof(*nf));
1916 		nfiles = nnf;
1917 		files = nf;
1918 	}
1919 	fflush(stdout);	/* force a semblance of order */
1920 	m = a;
1921 	if (a == GT) {
1922 		fp = fopen(s, "w");
1923 	} else if (a == APPEND) {
1924 		fp = fopen(s, "a");
1925 		m = GT;	/* so can mix > and >> */
1926 	} else if (a == '|') {	/* output pipe */
1927 		fp = popen(s, "w");
1928 	} else if (a == LE) {	/* input pipe */
1929 		fp = popen(s, "r");
1930 	} else if (a == LT) {	/* getline <file */
1931 		fp = strcmp(s, "-") == 0 ? stdin : fopen(s, "r");	/* "-" is stdin */
1932 	} else	/* can't happen */
1933 		FATAL("illegal redirection %d", a);
1934 	if (fp != NULL) {
1935 		files[i].fname = tostring(s);
1936 		files[i].fp = fp;
1937 		files[i].mode = m;
1938 		if (pnewflag)
1939 			*pnewflag = true;
1940 		if (fp != stdin && fp != stdout && fp != stderr)
1941 			(void) fcntl(fileno(fp), F_SETFD, FD_CLOEXEC);
1942 	}
1943 	return fp;
1944 }
1945 
1946 const char *filename(FILE *fp)
1947 {
1948 	size_t i;
1949 
1950 	for (i = 0; i < nfiles; i++)
1951 		if (fp == files[i].fp)
1952 			return files[i].fname;
1953 	return "???";
1954 }
1955 
1956  Cell *closefile(Node **a, int n)
1957  {
1958  	Cell *x;
1959 	size_t i;
1960 	bool stat;
1961 
1962  	x = execute(a[0]);
1963  	getsval(x);
1964 	stat = true;
1965  	for (i = 0; i < nfiles; i++) {
1966 		if (!files[i].fname || strcmp(x->sval, files[i].fname) != 0)
1967 			continue;
1968 		if (ferror(files[i].fp))
1969 			FATAL("i/o error occurred on %s", files[i].fname);
1970 		if (files[i].fp == stdin || files[i].fp == stdout ||
1971 		    files[i].fp == stderr)
1972 			stat = freopen("/dev/null", "r+", files[i].fp) == NULL;
1973 		else if (files[i].mode == '|' || files[i].mode == LE)
1974 			stat = pclose(files[i].fp) == -1;
1975 		else
1976 			stat = fclose(files[i].fp) == EOF;
1977 		if (stat)
1978 			FATAL("i/o error occurred closing %s", files[i].fname);
1979 		if (i > 2)	/* don't do /dev/std... */
1980 			xfree(files[i].fname);
1981 		files[i].fname = NULL;	/* watch out for ref thru this */
1982 		files[i].fp = NULL;
1983 		break;
1984  	}
1985  	tempfree(x);
1986  	x = gettemp();
1987 	setfval(x, (Awkfloat) (stat ? -1 : 0));
1988  	return(x);
1989  }
1990 
1991 void closeall(void)
1992 {
1993 	size_t i;
1994 	bool stat = false;
1995 
1996 	for (i = 0; i < nfiles; i++) {
1997 		if (! files[i].fp)
1998 			continue;
1999 		if (ferror(files[i].fp))
2000 			FATAL( "i/o error occurred on %s", files[i].fname );
2001 		if (files[i].fp == stdin)
2002 			continue;
2003 		if (files[i].mode == '|' || files[i].mode == LE)
2004 			stat = pclose(files[i].fp) == -1;
2005 		else if (files[i].fp == stdout || files[i].fp == stderr)
2006 			stat = fflush(files[i].fp) == EOF;
2007 		else
2008 			stat = fclose(files[i].fp) == EOF;
2009 		if (stat)
2010 			FATAL( "i/o error occurred while closing %s", files[i].fname );
2011 	}
2012 }
2013 
2014 static void flush_all(void)
2015 {
2016 	size_t i;
2017 
2018 	for (i = 0; i < nfiles; i++)
2019 		if (files[i].fp)
2020 			fflush(files[i].fp);
2021 }
2022 
2023 void backsub(char **pb_ptr, const char **sptr_ptr);
2024 
2025 Cell *sub(Node **a, int nnn)	/* substitute command */
2026 {
2027 	const char *sptr, *q;
2028 	Cell *x, *y, *result;
2029 	char *t, *buf, *pb;
2030 	fa *pfa;
2031 	int bufsz = recsize;
2032 
2033 	if ((buf = (char *) malloc(bufsz)) == NULL)
2034 		FATAL("out of memory in sub");
2035 	x = execute(a[3]);	/* target string */
2036 	t = getsval(x);
2037 	if (a[0] == NULL)	/* 0 => a[1] is already-compiled regexpr */
2038 		pfa = (fa *) a[1];	/* regular expression */
2039 	else {
2040 		y = execute(a[1]);
2041 		pfa = makedfa(getsval(y), 1);
2042 		tempfree(y);
2043 	}
2044 	y = execute(a[2]);	/* replacement string */
2045 	result = False;
2046 	if (pmatch(pfa, t)) {
2047 		sptr = t;
2048 		adjbuf(&buf, &bufsz, 1+patbeg-sptr, recsize, 0, "sub");
2049 		pb = buf;
2050 		while (sptr < patbeg)
2051 			*pb++ = *sptr++;
2052 		sptr = getsval(y);
2053 		while (*sptr != '\0') {
2054 			adjbuf(&buf, &bufsz, 5+pb-buf, recsize, &pb, "sub");
2055 			if (*sptr == '\\') {
2056 				backsub(&pb, &sptr);
2057 			} else if (*sptr == '&') {
2058 				sptr++;
2059 				adjbuf(&buf, &bufsz, 1+patlen+pb-buf, recsize, &pb, "sub");
2060 				for (q = patbeg; q < patbeg+patlen; )
2061 					*pb++ = *q++;
2062 			} else
2063 				*pb++ = *sptr++;
2064 		}
2065 		*pb = '\0';
2066 		if (pb > buf + bufsz)
2067 			FATAL("sub result1 %.30s too big; can't happen", buf);
2068 		sptr = patbeg + patlen;
2069 		if ((patlen == 0 && *patbeg) || (patlen && *(sptr-1))) {
2070 			adjbuf(&buf, &bufsz, 1+strlen(sptr)+pb-buf, 0, &pb, "sub");
2071 			while ((*pb++ = *sptr++) != '\0')
2072 				continue;
2073 		}
2074 		if (pb > buf + bufsz)
2075 			FATAL("sub result2 %.30s too big; can't happen", buf);
2076 		setsval(x, buf);	/* BUG: should be able to avoid copy */
2077 		result = True;
2078 	}
2079 	tempfree(x);
2080 	tempfree(y);
2081 	free(buf);
2082 	return result;
2083 }
2084 
2085 Cell *gsub(Node **a, int nnn)	/* global substitute */
2086 {
2087 	Cell *x, *y;
2088 	char *rptr, *pb;
2089 	const char *q, *t, *sptr;
2090 	char *buf;
2091 	fa *pfa;
2092 	int mflag, tempstat, num;
2093 	int bufsz = recsize;
2094 
2095 	if ((buf = (char *) malloc(bufsz)) == NULL)
2096 		FATAL("out of memory in gsub");
2097 	mflag = 0;	/* if mflag == 0, can replace empty string */
2098 	num = 0;
2099 	x = execute(a[3]);	/* target string */
2100 	t = getsval(x);
2101 	if (a[0] == NULL)	/* 0 => a[1] is already-compiled regexpr */
2102 		pfa = (fa *) a[1];	/* regular expression */
2103 	else {
2104 		y = execute(a[1]);
2105 		pfa = makedfa(getsval(y), 1);
2106 		tempfree(y);
2107 	}
2108 	y = execute(a[2]);	/* replacement string */
2109 	if (pmatch(pfa, t)) {
2110 		tempstat = pfa->initstat;
2111 		pfa->initstat = 2;
2112 		pb = buf;
2113 		rptr = getsval(y);
2114 		do {
2115 			if (patlen == 0 && *patbeg != '\0') {	/* matched empty string */
2116 				if (mflag == 0) {	/* can replace empty */
2117 					num++;
2118 					sptr = rptr;
2119 					while (*sptr != '\0') {
2120 						adjbuf(&buf, &bufsz, 5+pb-buf, recsize, &pb, "gsub");
2121 						if (*sptr == '\\') {
2122 							backsub(&pb, &sptr);
2123 						} else if (*sptr == '&') {
2124 							sptr++;
2125 							adjbuf(&buf, &bufsz, 1+patlen+pb-buf, recsize, &pb, "gsub");
2126 							for (q = patbeg; q < patbeg+patlen; )
2127 								*pb++ = *q++;
2128 						} else
2129 							*pb++ = *sptr++;
2130 					}
2131 				}
2132 				if (*t == '\0')	/* at end */
2133 					goto done;
2134 				adjbuf(&buf, &bufsz, 2+pb-buf, recsize, &pb, "gsub");
2135 				*pb++ = *t++;
2136 				if (pb > buf + bufsz)	/* BUG: not sure of this test */
2137 					FATAL("gsub result0 %.30s too big; can't happen", buf);
2138 				mflag = 0;
2139 			}
2140 			else {	/* matched nonempty string */
2141 				num++;
2142 				sptr = t;
2143 				adjbuf(&buf, &bufsz, 1+(patbeg-sptr)+pb-buf, recsize, &pb, "gsub");
2144 				while (sptr < patbeg)
2145 					*pb++ = *sptr++;
2146 				sptr = rptr;
2147 				while (*sptr != '\0') {
2148 					adjbuf(&buf, &bufsz, 5+pb-buf, recsize, &pb, "gsub");
2149 					if (*sptr == '\\') {
2150 						backsub(&pb, &sptr);
2151 					} else if (*sptr == '&') {
2152 						sptr++;
2153 						adjbuf(&buf, &bufsz, 1+patlen+pb-buf, recsize, &pb, "gsub");
2154 						for (q = patbeg; q < patbeg+patlen; )
2155 							*pb++ = *q++;
2156 					} else
2157 						*pb++ = *sptr++;
2158 				}
2159 				t = patbeg + patlen;
2160 				if (patlen == 0 || *t == '\0' || *(t-1) == '\0')
2161 					goto done;
2162 				if (pb > buf + bufsz)
2163 					FATAL("gsub result1 %.30s too big; can't happen", buf);
2164 				mflag = 1;
2165 			}
2166 		} while (pmatch(pfa,t));
2167 		sptr = t;
2168 		adjbuf(&buf, &bufsz, 1+strlen(sptr)+pb-buf, 0, &pb, "gsub");
2169 		while ((*pb++ = *sptr++) != '\0')
2170 			continue;
2171 	done:	if (pb < buf + bufsz)
2172 			*pb = '\0';
2173 		else if (*(pb-1) != '\0')
2174 			FATAL("gsub result2 %.30s truncated; can't happen", buf);
2175 		setsval(x, buf);	/* BUG: should be able to avoid copy + free */
2176 		pfa->initstat = tempstat;
2177 	}
2178 	tempfree(x);
2179 	tempfree(y);
2180 	x = gettemp();
2181 	x->tval = NUM;
2182 	x->fval = num;
2183 	free(buf);
2184 	return(x);
2185 }
2186 
2187 Cell *gensub(Node **a, int nnn)	/* global selective substitute */
2188 	/* XXX incomplete - doesn't support backreferences \0 ... \9 */
2189 {
2190 	Cell *x, *y, *res, *h;
2191 	char *rptr;
2192 	const char *sptr;
2193 	char *buf, *pb;
2194 	const char *t, *q;
2195 	fa *pfa;
2196 	int mflag, tempstat, num, whichm;
2197 	int bufsz = recsize;
2198 
2199 	if ((buf = malloc(bufsz)) == NULL)
2200 		FATAL("out of memory in gensub");
2201 	mflag = 0;	/* if mflag == 0, can replace empty string */
2202 	num = 0;
2203 	x = execute(a[4]);	/* source string */
2204 	t = getsval(x);
2205 	res = copycell(x);	/* target string - initially copy of source */
2206 	res->csub = CTEMP;	/* result values are temporary */
2207 	if (a[0] == 0)		/* 0 => a[1] is already-compiled regexpr */
2208 		pfa = (fa *) a[1];	/* regular expression */
2209 	else {
2210 		y = execute(a[1]);
2211 		pfa = makedfa(getsval(y), 1);
2212 		tempfree(y);
2213 	}
2214 	y = execute(a[2]);	/* replacement string */
2215 	h = execute(a[3]);	/* which matches should be replaced */
2216 	sptr = getsval(h);
2217 	if (sptr[0] == 'g' || sptr[0] == 'G')
2218 		whichm = -1;
2219 	else {
2220 		/*
2221 		 * The specified number is index of replacement, starting
2222 		 * from 1. GNU awk treats index lower than 0 same as
2223 		 * 1, we do same for compatibility.
2224 		 */
2225 		whichm = (int) getfval(h) - 1;
2226 		if (whichm < 0)
2227 			whichm = 0;
2228 	}
2229 	tempfree(h);
2230 
2231 	if (pmatch(pfa, t)) {
2232 		char *sl;
2233 
2234 		tempstat = pfa->initstat;
2235 		pfa->initstat = 2;
2236 		pb = buf;
2237 		rptr = getsval(y);
2238 		/*
2239 		 * XXX if there are any backreferences in subst string,
2240 		 * complain now.
2241 		 */
2242 		for (sl = rptr; (sl = strchr(sl, '\\')) && sl[1]; sl++) {
2243 			if (strchr("0123456789", sl[1])) {
2244 				FATAL("gensub doesn't support backreferences (subst \"%s\")", rptr);
2245 			}
2246 		}
2247 
2248 		do {
2249 			if (whichm >= 0 && whichm != num) {
2250 				num++;
2251 				adjbuf(&buf, &bufsz, (pb - buf) + (patbeg - t) + patlen, recsize, &pb, "gensub");
2252 
2253 				/* copy the part of string up to and including
2254 				 * match to output buffer */
2255 				while (t < patbeg + patlen)
2256 					*pb++ = *t++;
2257 				continue;
2258 			}
2259 
2260 			if (patlen == 0 && *patbeg != 0) {	/* matched empty string */
2261 				if (mflag == 0) {	/* can replace empty */
2262 					num++;
2263 					sptr = rptr;
2264 					while (*sptr != 0) {
2265 						adjbuf(&buf, &bufsz, 5+pb-buf, recsize, &pb, "gensub");
2266 						if (*sptr == '\\') {
2267 							backsub(&pb, &sptr);
2268 						} else if (*sptr == '&') {
2269 							sptr++;
2270 							adjbuf(&buf, &bufsz, 1+patlen+pb-buf, recsize, &pb, "gensub");
2271 							for (q = patbeg; q < patbeg+patlen; )
2272 								*pb++ = *q++;
2273 						} else
2274 							*pb++ = *sptr++;
2275 					}
2276 				}
2277 				if (*t == 0)	/* at end */
2278 					goto done;
2279 				adjbuf(&buf, &bufsz, 2+pb-buf, recsize, &pb, "gensub");
2280 				*pb++ = *t++;
2281 				if (pb > buf + bufsz)	/* BUG: not sure of this test */
2282 					FATAL("gensub result0 %.30s too big; can't happen", buf);
2283 				mflag = 0;
2284 			}
2285 			else {	/* matched nonempty string */
2286 				num++;
2287 				sptr = t;
2288 				adjbuf(&buf, &bufsz, 1+(patbeg-sptr)+pb-buf, recsize, &pb, "gensub");
2289 				while (sptr < patbeg)
2290 					*pb++ = *sptr++;
2291 				sptr = rptr;
2292 				while (*sptr != 0) {
2293 					adjbuf(&buf, &bufsz, 5+pb-buf, recsize, &pb, "gensub");
2294 					if (*sptr == '\\') {
2295 						backsub(&pb, &sptr);
2296 					} else if (*sptr == '&') {
2297 						sptr++;
2298 						adjbuf(&buf, &bufsz, 1+patlen+pb-buf, recsize, &pb, "gensub");
2299 						for (q = patbeg; q < patbeg+patlen; )
2300 							*pb++ = *q++;
2301 					} else
2302 						*pb++ = *sptr++;
2303 				}
2304 				t = patbeg + patlen;
2305 				if (patlen == 0 || *t == 0 || *(t-1) == 0)
2306 					goto done;
2307 				if (pb > buf + bufsz)
2308 					FATAL("gensub result1 %.30s too big; can't happen", buf);
2309 				mflag = 1;
2310 			}
2311 		} while (pmatch(pfa,t));
2312 		sptr = t;
2313 		adjbuf(&buf, &bufsz, 1+strlen(sptr)+pb-buf, 0, &pb, "gensub");
2314 		while ((*pb++ = *sptr++) != 0)
2315 			;
2316 	done:	if (pb > buf + bufsz)
2317 			FATAL("gensub result2 %.30s too big; can't happen", buf);
2318 		*pb = '\0';
2319 		setsval(res, buf);
2320 		pfa->initstat = tempstat;
2321 	}
2322 	tempfree(x);
2323 	tempfree(y);
2324 	free(buf);
2325 	return(res);
2326 }
2327 
2328 void backsub(char **pb_ptr, const char **sptr_ptr)	/* handle \\& variations */
2329 {						/* sptr[0] == '\\' */
2330 	char *pb = *pb_ptr;
2331 	const char *sptr = *sptr_ptr;
2332 	static bool first = true;
2333 	static bool do_posix = false;
2334 
2335 	if (first) {
2336 		first = false;
2337 		do_posix = (getenv("POSIXLY_CORRECT") != NULL);
2338 	}
2339 
2340 	if (sptr[1] == '\\') {
2341 		if (sptr[2] == '\\' && sptr[3] == '&') { /* \\\& -> \& */
2342 			*pb++ = '\\';
2343 			*pb++ = '&';
2344 			sptr += 4;
2345 		} else if (sptr[2] == '&') {	/* \\& -> \ + matched */
2346 			*pb++ = '\\';
2347 			sptr += 2;
2348 		} else if (do_posix) {		/* \\x -> \x */
2349 			sptr++;
2350 			*pb++ = *sptr++;
2351 		} else {			/* \\x -> \\x */
2352 			*pb++ = *sptr++;
2353 			*pb++ = *sptr++;
2354 		}
2355 	} else if (sptr[1] == '&') {	/* literal & */
2356 		sptr++;
2357 		*pb++ = *sptr++;
2358 	} else				/* literal \ */
2359 		*pb++ = *sptr++;
2360 
2361 	*pb_ptr = pb;
2362 	*sptr_ptr = sptr;
2363 }
2364