xref: /titanic_44/usr/src/ucblib/libucb/port/stdio/doprnt.c (revision 1cb6af97c6f66f456d4f726ef056e1ebc0f73305)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #pragma ident	"%Z%%M%	%I%	%E% SMI"
41 
42 /*LINTLIBRARY*/
43 
44 /*
45  *	_doprnt: common code for printf, fprintf, sprintf
46  */
47 
48 #include "../gen/synonyms.h"
49 #include <sys/types.h>
50 #include "file64.h"
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <ctype.h>
54 #include <stdarg.h>
55 #include <values.h>
56 #include <nan.h>
57 #include <memory.h>
58 #include <string.h>
59 #include "print.h"	/* parameters & macros for doprnt */
60 #include "stdiom.h"
61 #include <locale.h>
62 #include <stddef.h>
63 #include "_locale.h"
64 #include "libc.h"
65 
66 #define	PUT(p, n)	{ unsigned char *newbufptr; \
67 			if ((newbufptr = bufptr + (n)) > bufferend) { \
68 				_dowrite((p), (n), iop, &bufptr); \
69 			} else { \
70 				(void) memcpy(bufptr, (p), (n)); \
71 				bufptr = newbufptr; \
72 			} \
73 			}
74 #define	PAD(s, n)	{ int nn; \
75 			for (nn = (n); nn > 20; nn -= 20) \
76 				_dowrite((s), 20, iop, &bufptr); \
77 			PUT((s), nn); \
78 			}
79 
80 #define	SNLEN	5	/* Length of string used when printing a NaN */
81 
82 /* bit positions for flags used in doprnt */
83 
84 #define	LENGTH	1	/* l */
85 #define	FPLUS	2	/* + */
86 #define	FMINUS	  4	/* - */
87 #define	FBLANK	  8	/* blank */
88 #define	FSHARP	 16	/* # */
89 #define	PADZERO  32	/* padding zeroes requested via '0' */
90 #define	DOTSEEN  64	/* dot appeared in format specification */
91 #define	SUFFIX	128	/* a suffix is to appear in the output */
92 #define	RZERO	256	/* there will be trailing zeros in output */
93 #define	LZERO	512	/* there will be leading zeroes in output */
94 #define	SHORT  1024	/* h */
95 
96 /*
97  *	Positional Parameter information
98  */
99 #define	MAXARGS	30	/* max. number of args for fast positional paramters */
100 
101 /*
102  * stva_list is used to subvert C's restriction that a variable with an
103  * array type can not appear on the left hand side of an assignment operator.
104  * By putting the array inside a structure, the functionality of assigning to
105  * the whole array through a simple assignment is achieved..
106  */
107 typedef struct stva_list {
108 	va_list	ap;
109 } stva_list;
110 
111 static char _blanks[] = "                    ";
112 static char _zeroes[] = "00000000000000000000";
113 static char uc_digs[] = "0123456789ABCDEF";
114 static char lc_digs[] = "0123456789abcdef";
115 static char  lc_nan[] = "nan0x";
116 static char  uc_nan[] = "NAN0X";
117 static char  lc_inf[] = "inf";
118 static char  uc_inf[] = "INF";
119 
120 /*
121  * forward declarations
122  */
123 void _mkarglst(char *, stva_list, stva_list []);
124 void _getarg(char *, stva_list *, int);
125 static int _lowdigit(long *);
126 static void _dowrite(char *, ssize_t, FILE *, unsigned char **);
127 
128 static int
129 _lowdigit(long *valptr)
130 {	/* This function computes the decimal low-order digit of the number */
131 	/* pointed to by valptr, and returns this digit after dividing   */
132 	/* *valptr by ten.  This function is called ONLY to compute the */
133 	/* low-order digit of a long whose high-order bit is set. */
134 
135 	int lowbit = (int)(*valptr & 1);
136 	long value = (*valptr >> 1) & ~HIBITL;
137 
138 	*valptr = value / 5;
139 	return ((int)(value % 5 * 2 + lowbit + '0'));
140 }
141 
142 /* The function _dowrite carries out buffer pointer bookkeeping surrounding */
143 /* a call to fwrite.  It is called only when the end of the file output */
144 /* buffer is approached or in other unusual situations. */
145 static void
146 _dowrite(char *p, ssize_t n, FILE *iop, unsigned char **ptrptr)
147 {
148 	if (!(iop->_flag & _IOREAD)) {
149 		iop->_cnt -= (*ptrptr - iop->_ptr);
150 		iop->_ptr = *ptrptr;
151 		_bufsync(iop, _bufend(iop));
152 		(void) fwrite(p, 1, n, iop);
153 		*ptrptr = iop->_ptr;
154 	} else
155 		*ptrptr = (unsigned char *) memcpy(*ptrptr, p, n) + n;
156 }
157 
158 int
159 _doprnt(char *format, va_list in_args, FILE *iop)
160 {
161 
162 	/* bufptr is used inside of doprnt instead of iop->_ptr; */
163 	/* bufferend is a copy of _bufend(iop), if it exists.  For */
164 	/* dummy file descriptors (iop->_flag & _IOREAD), bufferend */
165 	/* may be meaningless. Dummy file descriptors are used so that */
166 	/* sprintf and vsprintf may share the _doprnt routine with the */
167 	/* rest of the printf family. */
168 
169 	unsigned char *bufptr;
170 	unsigned char *bufferend;
171 
172 	/* This variable counts output characters. */
173 	int	count = 0;
174 
175 	/* Starting and ending points for value to be printed */
176 	char	*bp;
177 	char	*p;
178 
179 	/* Field width and precision */
180 	int	width, prec;
181 
182 	/* Format code */
183 	int	fcode;
184 
185 	/* Number of padding zeroes required on the left and right */
186 	int	lzero, rzero;
187 
188 	/* Flags - bit positions defined by LENGTH, FPLUS, FMINUS, FBLANK, */
189 	/* and FSHARP are set if corresponding character is in format */
190 	/* Bit position defined by PADZERO means extra space in the field */
191 	/* should be padded with leading zeroes rather than with blanks */
192 	int	flagword;
193 
194 	/* Values are developed in this buffer */
195 	char	buf[max(MAXDIGS, 1+max(MAXFCVT+MAXEXP, MAXECVT))];
196 
197 	/* Pointer to sign, "0x", "0X", or empty */
198 	char	*prefix;
199 
200 	/* Exponent or empty */
201 	char	*suffix;
202 
203 	/* Buffer to create exponent */
204 	char	expbuf[MAXESIZ + 1];
205 
206 	/* Length of prefix and of suffix */
207 	int	prefixlength, suffixlength;
208 
209 	/* Combined length of leading zeroes, trailing zeroes, and suffix */
210 	int 	otherlength;
211 
212 	/* The value being converted, if integer */
213 	long	val;
214 
215 	/* The value being converted, if real */
216 	double	dval;
217 
218 	/* Output values from fcvt and ecvt */
219 	int	decpt, sign;
220 
221 	/* Pointer to a translate table for digits of whatever radix */
222 	char	*tab;
223 
224 	/* Work variables */
225 	int	k, lradix, mradix;
226 
227 	/* Variables used to flag an infinities and nans, resp. */
228 	/* Nan_flg is used with two purposes: to flag a NaN and */
229 	/* as the length of the string ``NAN0X'' (``nan0x'') */
230 	int	 inf_nan = 0, NaN_flg = 0;
231 
232 	/* Pointer to string "NAN0X" or "nan0x" */
233 	char	 *SNAN;
234 
235 	/* Flag for negative infinity or NaN */
236 	int neg_in = 0;
237 
238 	/* variables for positional parameters */
239 	char	*sformat = format;	/* save the beginning of the format */
240 	int	fpos = 1;		/* 1 if first positional parameter */
241 	stva_list args;		/* used to step through the argument list */
242 	stva_list sargs;
243 		/* used to save the start of the argument list */
244 	stva_list bargs;
245 		/* used to restore args if positional width or precision */
246 	stva_list arglst[MAXARGS];
247 		/*
248 		 * array giving the appropriate values for va_arg() to
249 		 * retrieve the corresponding argument:
250 		 * arglst[0] is the first argument,
251 		 * arglst[1] is the second argument, etc.
252 		 */
253 	int	starflg = 0;	/* set to 1 if * format specifier seen */
254 	/*
255 	 * Initialize args and sargs to the start of the argument list.
256 	 * Note that ANSI guarantees that the address of the first member of
257 	 * a structure will be the same as the address of the structure.
258 	 * See equivalent code in libc doprnt.c
259 	 */
260 
261 #if !(defined(__amd64) && defined(__GNUC__))	/* XX64 - fix me */
262 	va_copy(args.ap, in_args);
263 #endif
264 	sargs = args;
265 
266 	/* if first I/O to the stream get a buffer */
267 	/* Note that iop->_base should not equal 0 for sprintf and vsprintf */
268 	if (iop->_base == 0 && _findbuf(iop) == 0)
269 		return (EOF);
270 
271 	/* initialize buffer pointer and buffer end pointer */
272 	bufptr = iop->_ptr;
273 	bufferend = (iop->_flag & _IOREAD) ?
274 		(unsigned char *)((long)bufptr | (-1L & ~HIBITL))
275 		: _bufend(iop);
276 
277 	/*
278 	 *	The main loop -- this loop goes through one iteration
279 	 *	for each string of ordinary characters or format specification.
280 	 */
281 	for (;;) {
282 		ptrdiff_t pdiff;
283 
284 		if ((fcode = *format) != '\0' && fcode != '%') {
285 			bp = format;
286 			do {
287 				format++;
288 			} while ((fcode = *format) != '\0' && fcode != '%');
289 
290 			pdiff = format - bp;
291 				/* pdiff = no. of non-% chars */
292 			count += pdiff;
293 			PUT(bp, pdiff);
294 		}
295 		if (fcode == '\0') {  /* end of format; return */
296 			ptrdiff_t d = bufptr - iop->_ptr;
297 			iop->_cnt -= d;
298 			iop->_ptr = bufptr;
299 			if (bufptr + iop->_cnt > bufferend &&
300 			    !(iop->_flag & _IOREAD))
301 				_bufsync(iop, bufferend);
302 				/*
303 				 * in case of interrupt during last
304 				 * several lines
305 				 */
306 			if (iop->_flag & (_IONBF | _IOLBF) &&
307 			    (iop->_flag & _IONBF ||
308 			    memchr((char *)(bufptr-count), '\n', count) !=
309 			    NULL))
310 				(void) _xflsbuf(iop);
311 			return (ferror(iop) ? EOF : count);
312 		}
313 
314 		/*
315 		 *	% has been found.
316 		 *	The following switch is used to parse the format
317 		 *	specification and to perform the operation specified
318 		 *	by the format letter.  The program repeatedly goes
319 		 *	back to this switch until the format letter is
320 		 *	encountered.
321 		 */
322 		width = prefixlength = otherlength = flagword =
323 			suffixlength = 0;
324 		format++;
325 
326 	charswitch:
327 
328 		switch (fcode = *format++) {
329 
330 		case '+':
331 			flagword |= FPLUS;
332 			goto charswitch;
333 		case '-':
334 			flagword |= FMINUS;
335 			flagword &= ~PADZERO; /* ignore 0 flag */
336 			goto charswitch;
337 		case ' ':
338 			flagword |= FBLANK;
339 			goto charswitch;
340 		case '#':
341 			flagword |= FSHARP;
342 			goto charswitch;
343 
344 		/* Scan the field width and precision */
345 		case '.':
346 			flagword |= DOTSEEN;
347 			prec = 0;
348 			goto charswitch;
349 
350 		case '*':
351 			if (isdigit(*format)) {
352 				starflg = 1;
353 				bargs = args;
354 				goto charswitch;
355 			}
356 			if (!(flagword & DOTSEEN)) {
357 				width = va_arg(args.ap, int);
358 				if (width < 0) {
359 					width = -width;
360 					flagword ^= FMINUS;
361 				}
362 			} else {
363 				prec = va_arg(args.ap, int);
364 				if (prec < 0)
365 					prec = 0;
366 			}
367 			goto charswitch;
368 
369 		case '$':
370 			{
371 			int		position;
372 			stva_list	targs;
373 			if (fpos) {
374 				_mkarglst(sformat, sargs, arglst);
375 				fpos = 0;
376 			}
377 			if (flagword & DOTSEEN) {
378 				position = prec;
379 				prec = 0;
380 			} else {
381 				position = width;
382 				width = 0;
383 			}
384 			if (position <= 0) {
385 				/* illegal position */
386 				format--;
387 				continue;
388 			}
389 			if (position <= MAXARGS) {
390 				targs = arglst[position - 1];
391 			} else {
392 				targs = arglst[MAXARGS - 1];
393 				_getarg(sformat, &targs, position);
394 			}
395 			if (!starflg)
396 				args = targs;
397 			else {
398 				starflg = 0;
399 				args = bargs;
400 				if (flagword & DOTSEEN)
401 					prec = va_arg(targs.ap, int);
402 				else
403 					width = va_arg(targs.ap, int);
404 			}
405 			goto charswitch;
406 			}
407 
408 		case '0':	/* obsolescent spec:  leading zero in width */
409 				/* means pad with leading zeros */
410 			if (!(flagword & (DOTSEEN | FMINUS)))
411 				flagword |= PADZERO;
412 			/* FALLTHROUGH */
413 		case '1':
414 		case '2':
415 		case '3':
416 		case '4':
417 		case '5':
418 		case '6':
419 		case '7':
420 		case '8':
421 		case '9':
422 			{ 	int num = fcode - '0';
423 				while (isdigit(fcode = *format)) {
424 					num = num * 10 + fcode - '0';
425 					format++;
426 				}
427 				if (flagword & DOTSEEN)
428 					prec = num;
429 				else
430 					width = num;
431 				goto charswitch;
432 			}
433 
434 		/* Scan the length modifier */
435 		case 'l':
436 			flagword |= LENGTH;
437 			goto charswitch;
438 		case 'h':
439 			flagword |= SHORT;
440 			goto charswitch;
441 		case 'L':
442 			goto charswitch;
443 
444 		/*
445 		 *	The character addressed by format must be
446 		 *	the format letter -- there is nothing
447 		 *	left for it to be.
448 		 *
449 		 *	The status of the +, -, #, and blank
450 		 *	flags are reflected in the variable
451 		 *	"flagword".  "width" and "prec" contain
452 		 *	numbers corresponding to the digit
453 		 *	strings before and after the decimal
454 		 *	point, respectively. If there was no
455 		 *	decimal point, then flagword & DOTSEEN
456 		 *	is false and the value of prec is meaningless.
457 		 *
458 		 *	The following switch cases set things up
459 		 *	for printing.  What ultimately gets
460 		 *	printed will be padding blanks, a
461 		 *	prefix, left padding zeroes, a value,
462 		 *	right padding zeroes, a suffix, and
463 		 *	more padding blanks.  Padding blanks
464 		 *	will not appear simultaneously on both
465 		 *	the left and the right.  Each case in
466 		 *	this switch will compute the value, and
467 		 *	leave in several variables the informa-
468 		 *	tion necessary to construct what is to
469 		 *	be printed.
470 		 *
471 		 *	The prefix is a sign, a blank, "0x",
472 		 *	"0X", or null, and is addressed by
473 		 *	"prefix".
474 		 *
475 		 *	The suffix is either null or an
476 		 *	exponent, and is addressed by "suffix".
477 		 *	If there is a suffix, the flagword bit
478 		 *	SUFFIX will be set.
479 		 *
480 		 *	The value to be printed starts at "bp"
481 		 *	and continues up to and not including
482 		 *	"p".
483 		 *
484 		 *	"lzero" and "rzero" will contain the
485 		 *	number of padding zeroes required on
486 		 *	the left and right, respectively.
487 		 *	The flagword bits LZERO and RZERO tell
488 		 *	whether padding zeros are required.
489 		 *
490 		 *	The number of padding blanks, and
491 		 *	whether they go on the left or the
492 		 *	right, will be computed on exit from
493 		 *	the switch.
494 		 */
495 
496 
497 
498 
499 		/*
500 		 *	decimal fixed point representations
501 		 *
502 		 *	HIBITL is 100...000
503 		 *	binary, and is equal to	the maximum
504 		 *	negative number.
505 		 *	We assume a 2's complement machine
506 		 */
507 
508 		case 'i':
509 		case 'd':
510 			/* Fetch the argument to be printed */
511 			if (flagword & LENGTH)
512 				val = va_arg(args.ap, long);
513 			else
514 				val = va_arg(args.ap, int);
515 
516 			if (flagword & SHORT)
517 				val = (short)val;
518 
519 			/* Set buffer pointer to last digit */
520 			p = bp = buf + MAXDIGS;
521 
522 			/* If signed conversion, make sign */
523 			if (val < 0) {
524 				prefix = "-";
525 				prefixlength = 1;
526 				/*
527 				 * Negate, checking in
528 				 * advance for possible
529 				 * overflow.
530 				 */
531 				if (val != HIBITL)
532 					val = -val;
533 				else	/* number is -HIBITL; convert last */
534 					/* digit now and get positive number */
535 					*--bp = _lowdigit(&val);
536 			} else if (flagword & FPLUS) {
537 				prefix = "+";
538 				prefixlength = 1;
539 			} else if (flagword & FBLANK) {
540 				prefix = " ";
541 				prefixlength = 1;
542 			}
543 
544 		decimal:
545 			{	long qval = val;
546 				long saveq;
547 
548 				if (qval <= 9) {
549 					if (qval != 0 || !(flagword & DOTSEEN))
550 						*--bp = (char)(qval + '0');
551 				} else {
552 					do {
553 						saveq = qval;
554 						qval /= 10;
555 						*--bp = (char)(saveq -
556 							qval * 10 + '0');
557 					} while (qval > 9);
558 					*--bp = (char)(qval + '0');
559 					pdiff = (ptrdiff_t)saveq;
560 				}
561 			}
562 
563 			/* Calculate minimum padding zero requirement */
564 			if (flagword & DOTSEEN) {
565 				int leadzeroes = prec - (int)(p - bp);
566 				if (leadzeroes > 0) {
567 					otherlength = lzero = leadzeroes;
568 					flagword |= LZERO;
569 				}
570 			}
571 
572 			break;
573 
574 		case 'u':
575 			/* Fetch the argument to be printed */
576 			if (flagword & LENGTH)
577 				val = va_arg(args.ap, long);
578 			else
579 				val = va_arg(args.ap, unsigned);
580 
581 			if (flagword & SHORT)
582 				val = (unsigned short)val;
583 
584 			p = bp = buf + MAXDIGS;
585 
586 			if (val & HIBITL)
587 				*--bp = _lowdigit(&val);
588 
589 			goto decimal;
590 
591 		/*
592 		 *	non-decimal fixed point representations
593 		 *	for radix equal to a power of two
594 		 *
595 		 *	"mradix" is one less than the radix for the conversion.
596 		 *	"lradix" is one less than the base 2 log
597 		 *	of the radix for the conversion. Conversion is unsigned.
598 		 *	HIBITL is 100...000
599 		 *	binary, and is equal to	the maximum
600 		 *	negative number.
601 		 *	We assume a 2's complement machine
602 		 */
603 
604 		case 'o':
605 			mradix = 7;
606 			lradix = 2;
607 			goto fixed;
608 
609 		case 'X':
610 		case 'x':
611 		case 'p':
612 			mradix = 15;
613 			lradix = 3;
614 
615 		fixed:
616 			/* Fetch the argument to be printed */
617 			if (flagword & LENGTH)
618 				val = va_arg(args.ap, long);
619 			else
620 				val = va_arg(args.ap, unsigned);
621 
622 			if (flagword & SHORT)
623 				val = (unsigned short)val;
624 
625 			/* Set translate table for digits */
626 			tab = (fcode == 'X') ? uc_digs : lc_digs;
627 
628 			/* Entry point when printing a double which is a NaN */
629 		put_pc:
630 			/* Develop the digits of the value */
631 			p = bp = buf + MAXDIGS;
632 			{	long qval = val;
633 				if (qval == 0) {
634 					if (!(flagword & DOTSEEN)) {
635 						otherlength = lzero = 1;
636 						flagword |= LZERO;
637 					}
638 				} else
639 					do {
640 						*--bp = tab[qval & mradix];
641 						qval = ((qval >> 1) & ~HIBITL)
642 								>> lradix;
643 					} while (qval != 0);
644 			}
645 
646 			/* Calculate minimum padding zero requirement */
647 			if (flagword & DOTSEEN) {
648 				int leadzeroes = prec - (int)(p - bp);
649 				if (leadzeroes > 0) {
650 					otherlength = lzero = leadzeroes;
651 					flagword |= LZERO;
652 				}
653 			}
654 
655 			/* Handle the # flag */
656 			if (flagword & FSHARP && val != 0)
657 				switch (fcode) {
658 				case 'o':
659 					if (!(flagword & LZERO)) {
660 						otherlength = lzero = 1;
661 						flagword |= LZERO;
662 					}
663 					break;
664 				case 'x':
665 					prefix = "0x";
666 					prefixlength = 2;
667 					break;
668 				case 'X':
669 					prefix = "0X";
670 					prefixlength = 2;
671 					break;
672 				}
673 
674 			break;
675 
676 		case 'E':
677 		case 'e':
678 			/*
679 			 * E-format.  The general strategy
680 			 * here is fairly easy: we take
681 			 * what ecvt gives us and re-format it.
682 			 */
683 
684 			/* Establish default precision */
685 			if (!(flagword & DOTSEEN))
686 				prec = 6;
687 
688 			/* Fetch the value */
689 			dval = va_arg(args.ap, double);
690 
691 			/* Check for NaNs and Infinities */
692 			if (IsNANorINF(dval)) {
693 				if (IsINF(dval)) {
694 					if (IsNegNAN(dval))
695 						neg_in = 1;
696 					inf_nan = 1;
697 					bp = (fcode == 'E')? uc_inf: lc_inf;
698 					p = bp + 3;
699 					break;
700 				} else {
701 					if (IsNegNAN(dval))
702 						neg_in = 1;
703 					inf_nan = 1;
704 					val = GETNaNPC(dval);
705 					NaN_flg = SNLEN;
706 					mradix = 15;
707 					lradix = 3;
708 					if (fcode == 'E') {
709 						SNAN = uc_nan;
710 						tab =  uc_digs;
711 					} else {
712 						SNAN =  lc_nan;
713 						tab =  lc_digs;
714 					}
715 					goto put_pc;
716 				}
717 			}
718 			/* Develop the mantissa */
719 			bp = ecvt(dval, min(prec + 1, MAXECVT), &decpt, &sign);
720 
721 			/* Determine the prefix */
722 		e_merge:
723 			if (sign) {
724 				prefix = "-";
725 				prefixlength = 1;
726 			} else if (flagword & FPLUS) {
727 				prefix = "+";
728 				prefixlength = 1;
729 			} else if (flagword & FBLANK) {
730 				prefix = " ";
731 				prefixlength = 1;
732 			}
733 
734 			/* Place the first digit in the buffer */
735 			p = &buf[0];
736 			*p++ = (*bp != '\0') ? *bp++ : '0';
737 
738 			/* Put in a decimal point if needed */
739 			if (prec != 0 || (flagword & FSHARP))
740 				*p++ = _numeric[0];
741 
742 			/* Create the rest of the mantissa */
743 			{	int rz = prec;
744 				for (; rz > 0 && *bp != '\0'; --rz)
745 					*p++ = *bp++;
746 				if (rz > 0) {
747 					otherlength = rzero = rz;
748 					flagword |= RZERO;
749 				}
750 			}
751 
752 			bp = &buf[0];
753 
754 			/* Create the exponent */
755 			*(suffix = &expbuf[MAXESIZ]) = '\0';
756 			if (dval != 0) {
757 				int nn = decpt - 1;
758 				if (nn < 0)
759 				    nn = -nn;
760 				for (; nn > 9; nn /= 10)
761 					*--suffix = todigit(nn % 10);
762 				*--suffix = todigit(nn);
763 			}
764 
765 			/* Prepend leading zeroes to the exponent */
766 			while (suffix > &expbuf[MAXESIZ - 2])
767 				*--suffix = '0';
768 
769 			/* Put in the exponent sign */
770 			*--suffix = (decpt > 0 || dval == 0) ? '+' : '-';
771 
772 			/* Put in the e */
773 			*--suffix = isupper(fcode) ? 'E'  : 'e';
774 
775 			/* compute size of suffix */
776 			otherlength += (suffixlength =
777 				(int)(&expbuf[MAXESIZ] - suffix));
778 			flagword |= SUFFIX;
779 
780 			break;
781 
782 		case 'f':
783 			/*
784 			 * F-format floating point.  This is a
785 			 * good deal less simple than E-format.
786 			 * The overall strategy will be to call
787 			 * fcvt, reformat its result into buf,
788 			 * and calculate how many trailing
789 			 * zeroes will be required.  There will
790 			 * never be any leading zeroes needed.
791 			 */
792 
793 			/* Establish default precision */
794 			if (!(flagword & DOTSEEN))
795 				prec = 6;
796 
797 			/* Fetch the value */
798 			dval = va_arg(args.ap, double);
799 
800 			/* Check for NaNs and Infinities  */
801 			if (IsNANorINF(dval)) {
802 				if (IsINF(dval)) {
803 					if (IsNegNAN(dval))
804 						neg_in = 1;
805 					inf_nan = 1;
806 					bp = lc_inf;
807 					p = bp + 3;
808 					break;
809 				} else {
810 					if (IsNegNAN(dval))
811 						neg_in = 1;
812 					inf_nan = 1;
813 					val  = GETNaNPC(dval);
814 					NaN_flg = SNLEN;
815 					mradix = 15;
816 					lradix = 3;
817 					tab =  lc_digs;
818 					SNAN = lc_nan;
819 					goto put_pc;
820 				}
821 			}
822 			/* Do the conversion */
823 			bp = fcvt(dval, min(prec, MAXFCVT), &decpt, &sign);
824 
825 			/* Determine the prefix */
826 		f_merge:
827 			if (sign) {
828 				prefix = "-";
829 				prefixlength = 1;
830 			} else if (flagword & FPLUS) {
831 				prefix = "+";
832 				prefixlength = 1;
833 			} else if (flagword & FBLANK) {
834 				prefix = " ";
835 				prefixlength = 1;
836 			}
837 
838 			/* Initialize buffer pointer */
839 			p = &buf[0];
840 
841 			{	int nn = decpt;
842 
843 				/* Emit the digits before the decimal point */
844 				k = 0;
845 				do {
846 					*p++ = (nn <= 0 || *bp == '\0' ||
847 						k >= MAXFSIG) ?
848 						'0' : (k++, *bp++);
849 				} while (--nn > 0);
850 
851 				/* Decide whether we need a decimal point */
852 				if ((flagword & FSHARP) || prec > 0)
853 					*p++ = _numeric[0];
854 
855 				/* Digits (if any) after the decimal point */
856 				nn = min(prec, MAXFCVT);
857 				if (prec > nn) {
858 					flagword |= RZERO;
859 					otherlength = rzero = prec - nn;
860 				}
861 				while (--nn >= 0)
862 					*p++ = (++decpt <= 0 || *bp == '\0' ||
863 						k >= MAXFSIG) ?
864 						'0' : (k++, *bp++);
865 			}
866 
867 			bp = &buf[0];
868 
869 			break;
870 
871 		case 'G':
872 		case 'g':
873 			/*
874 			 * g-format.  We play around a bit
875 			 * and then jump into e or f, as needed.
876 			 */
877 
878 			/* Establish default precision */
879 			if (!(flagword & DOTSEEN))
880 				prec = 6;
881 			else if (prec == 0)
882 				prec = 1;
883 
884 			/* Fetch the value */
885 			dval = va_arg(args.ap, double);
886 
887 			/* Check for NaN and Infinities  */
888 			if (IsNANorINF(dval)) {
889 				if (IsINF(dval)) {
890 					if (IsNegNAN(dval))
891 						neg_in = 1;
892 					bp = (fcode == 'G') ? uc_inf : lc_inf;
893 					p = bp + 3;
894 					inf_nan = 1;
895 					break;
896 				} else {
897 					if (IsNegNAN(dval))
898 						neg_in = 1;
899 					inf_nan = 1;
900 					val  = GETNaNPC(dval);
901 					NaN_flg = SNLEN;
902 					mradix = 15;
903 					lradix = 3;
904 					if (fcode == 'G') {
905 						SNAN = uc_nan;
906 						tab = uc_digs;
907 					} else {
908 						SNAN = lc_nan;
909 						tab =  lc_digs;
910 					}
911 					goto put_pc;
912 				}
913 			}
914 
915 			/* Do the conversion */
916 			bp = ecvt(dval, min(prec, MAXECVT), &decpt, &sign);
917 			if (dval == 0)
918 				decpt = 1;
919 
920 			{	int kk = prec;
921 				size_t sz;
922 
923 				if (!(flagword & FSHARP)) {
924 					sz = strlen(bp);
925 					if (sz < kk)
926 						kk = (int)sz;
927 					while (kk >= 1 && bp[kk-1] == '0')
928 						--kk;
929 				}
930 
931 				if (decpt < -3 || decpt > prec) {
932 					prec = kk - 1;
933 					goto e_merge;
934 				}
935 				prec = kk - decpt;
936 				goto f_merge;
937 			}
938 
939 		case '%':
940 			buf[0] = (char)fcode;
941 			goto c_merge;
942 
943 		case 'c':
944 			buf[0] = va_arg(args.ap, int);
945 		c_merge:
946 			p = (bp = &buf[0]) + 1;
947 			break;
948 
949 		case 's':
950 			bp = va_arg(args.ap, char *);
951 			if (!(flagword & DOTSEEN))
952 				p = bp + strlen(bp);
953 			else { /* a strnlen function would  be useful here! */
954 				char *qp = bp;
955 				while (*qp++ != '\0' && --prec >= 0)
956 					;
957 				p = qp - 1;
958 			}
959 			break;
960 
961 		case 'n':
962 			{
963 				if (flagword & LENGTH) {
964 					long *svcount;
965 					svcount = va_arg(args.ap, long *);
966 					*svcount = count;
967 				} else if (flagword & SHORT) {
968 					short *svcount;
969 					svcount = va_arg(args.ap, short *);
970 					*svcount = (short)count;
971 				} else {
972 					int *svcount;
973 					svcount = va_arg(args.ap, int *);
974 					*svcount = count;
975 				}
976 				continue;
977 			}
978 
979 		default: /* this is technically an error; what we do is to */
980 			/* back up the format pointer to the offending char */
981 			/* and continue with the format scan */
982 			format--;
983 			continue;
984 
985 		}
986 
987 		if (inf_nan) {
988 			if (neg_in) {
989 				prefix = "-";
990 				prefixlength = 1;
991 				neg_in = 0;
992 			} else if (flagword & FPLUS) {
993 				prefix = "+";
994 				prefixlength = 1;
995 			} else if (flagword & FBLANK) {
996 				prefix = " ";
997 				prefixlength = 1;
998 			}
999 			inf_nan = 0;
1000 		}
1001 
1002 		/* Calculate number of padding blanks */
1003 		k = (int)(pdiff = p - bp) + prefixlength + otherlength +
1004 			NaN_flg;
1005 		if (width <= k)
1006 			count += k;
1007 		else {
1008 			count += width;
1009 
1010 			/* Set up for padding zeroes if requested */
1011 			/* Otherwise emit padding blanks unless output is */
1012 			/* to be left-justified.  */
1013 
1014 			if (flagword & PADZERO) {
1015 				if (!(flagword & LZERO)) {
1016 					flagword |= LZERO;
1017 					lzero = width - k;
1018 				}
1019 				else
1020 					lzero += width - k;
1021 				k = width; /* cancel padding blanks */
1022 			} else
1023 				/* Blanks on left if required */
1024 				if (!(flagword & FMINUS))
1025 					PAD(_blanks, width - k);
1026 		}
1027 
1028 		/* Prefix, if any */
1029 		if (prefixlength != 0)
1030 			PUT(prefix, prefixlength);
1031 
1032 		/* If value is NaN, put string NaN */
1033 		if (NaN_flg) {
1034 			PUT(SNAN, SNLEN);
1035 			NaN_flg = 0;
1036 		}
1037 
1038 		/* Zeroes on the left */
1039 		if (flagword & LZERO)
1040 			PAD(_zeroes, lzero);
1041 
1042 		/* The value itself */
1043 		if (pdiff > 0)
1044 			PUT(bp, pdiff);
1045 
1046 		if (flagword & (RZERO | SUFFIX | FMINUS)) {
1047 			/* Zeroes on the right */
1048 			if (flagword & RZERO)
1049 				PAD(_zeroes, rzero);
1050 
1051 			/* The suffix */
1052 			if (flagword & SUFFIX)
1053 				PUT(suffix, suffixlength);
1054 
1055 			/* Blanks on the right if required */
1056 			if (flagword & FMINUS && width > k)
1057 				PAD(_blanks, width - k);
1058 		}
1059 	}
1060 }
1061 
1062 /*
1063  * This function initializes arglst, to contain the appropriate va_list values
1064  * for the first MAXARGS arguments.
1065  */
1066 void
1067 _mkarglst(char *fmt, stva_list args, stva_list arglst[])
1068 {
1069 	static char digits[] = "01234567890", skips[] = "# +-.0123456789hL$";
1070 
1071 	enum types {INT = 1, LONG, CHAR_PTR, DOUBLE, LONG_DOUBLE, VOID_PTR,
1072 		LONG_PTR, INT_PTR};
1073 	enum types typelst[MAXARGS], curtype;
1074 	int maxnum, n, curargno, flags;
1075 
1076 	/*
1077 	 * Algorithm	1. set all argument types to zero.
1078 	 *		2. walk through fmt putting arg types in typelst[].
1079 	 *		3. walk through args using va_arg(args.ap, typelst[n])
1080 	 *		   and set arglst[] to the appropriate values.
1081 	 * Assumptions:	Cannot use %*$... to specify variable position.
1082 	 */
1083 
1084 	(void) memset((void *)typelst, 0, sizeof (typelst));
1085 	maxnum = -1;
1086 	curargno = 0;
1087 	while ((fmt = strchr(fmt, '%')) != 0) {
1088 		size_t sz;
1089 
1090 		fmt++;	/* skip % */
1091 		if (fmt[sz = strspn(fmt, digits)] == '$') {
1092 			curargno = atoi(fmt) - 1;
1093 				/* convert to zero base */
1094 			if (curargno < 0)
1095 				continue;
1096 			fmt += sz + 1;
1097 		}
1098 		flags = 0;
1099 	again:;
1100 		fmt += strspn(fmt, skips);
1101 		switch (*fmt++) {
1102 		case '%':	/* there is no argument! */
1103 			continue;
1104 		case 'l':
1105 			flags |= 0x1;
1106 			goto again;
1107 		case '*':	/* int argument used for value */
1108 			/* check if there is a positional parameter */
1109 			if (isdigit(*fmt)) {
1110 				int	targno;
1111 				targno = atoi(fmt) - 1;
1112 				fmt += strspn(fmt, digits);
1113 				if (*fmt == '$')
1114 					fmt++; /* skip '$' */
1115 				if (targno >= 0 && targno < MAXARGS) {
1116 					typelst[targno] = INT;
1117 					if (maxnum < targno)
1118 						maxnum = targno;
1119 				}
1120 				goto again;
1121 			}
1122 			flags |= 0x2;
1123 			curtype = INT;
1124 			break;
1125 		case 'e':
1126 		case 'E':
1127 		case 'f':
1128 		case 'g':
1129 		case 'G':
1130 			curtype = DOUBLE;
1131 			break;
1132 		case 's':
1133 			curtype = CHAR_PTR;
1134 			break;
1135 		case 'p':
1136 			curtype = VOID_PTR;
1137 			break;
1138 		case 'n':
1139 			if (flags & 0x1)
1140 				curtype = LONG_PTR;
1141 			else
1142 				curtype = INT_PTR;
1143 			break;
1144 		default:
1145 			if (flags & 0x1)
1146 				curtype = LONG;
1147 			else
1148 				curtype = INT;
1149 			break;
1150 		}
1151 		if (curargno >= 0 && curargno < MAXARGS) {
1152 			typelst[curargno] = curtype;
1153 			if (maxnum < curargno)
1154 				maxnum = curargno;
1155 		}
1156 		curargno++;	/* default to next in list */
1157 		if (flags & 0x2)	/* took care of *, keep going */
1158 		{
1159 			flags ^= 0x2;
1160 			goto again;
1161 		}
1162 	}
1163 	for (n = 0; n <= maxnum; n++) {
1164 		arglst[n] = args;
1165 		if (typelst[n] == 0)
1166 			typelst[n] = INT;
1167 
1168 		switch (typelst[n]) {
1169 		case INT:
1170 			(void) va_arg(args.ap, int);
1171 			break;
1172 		case LONG:
1173 			(void) va_arg(args.ap, long);
1174 			break;
1175 		case CHAR_PTR:
1176 			(void) va_arg(args.ap, char *);
1177 			break;
1178 		case DOUBLE:
1179 			(void) va_arg(args.ap, double);
1180 			break;
1181 		case LONG_DOUBLE:
1182 			(void) va_arg(args.ap, double);
1183 			break;
1184 		case VOID_PTR:
1185 			(void) va_arg(args.ap, void *);
1186 			break;
1187 		case LONG_PTR:
1188 			(void) va_arg(args.ap, long *);
1189 			break;
1190 		case INT_PTR:
1191 			(void) va_arg(args.ap, int *);
1192 			break;
1193 		}
1194 	}
1195 }
1196 
1197 /*
1198  * This function is used to find the va_list value for arguments whose
1199  * position is greater than MAXARGS.  This function is slow, so hopefully
1200  * MAXARGS will be big enough so that this function need only be called in
1201  * unusual circumstances.
1202  * pargs is assumed to contain the value of arglst[MAXARGS - 1].
1203  */
1204 void
1205 _getarg(char *fmt, stva_list *pargs, int argno)
1206 {
1207 	static char digits[] = "01234567890", skips[] = "# +-.0123456789h$";
1208 	int i, curargno, flags;
1209 	size_t n;
1210 	char	*sfmt = fmt;
1211 	int	found = 1;
1212 
1213 	i = MAXARGS;
1214 	curargno = 1;
1215 	while (found) {
1216 		fmt = sfmt;
1217 		found = 0;
1218 		while ((i != argno) && (fmt = strchr(fmt, '%')) != 0) {
1219 			fmt++;	/* skip % */
1220 			if (fmt[n = strspn(fmt, digits)] == '$') {
1221 				curargno = atoi(fmt);
1222 				if (curargno <= 0)
1223 					continue;
1224 				fmt += n + 1;
1225 			}
1226 
1227 			/* find conversion specifier for next argument */
1228 			if (i != curargno) {
1229 				curargno++;
1230 				continue;
1231 			} else
1232 				found = 1;
1233 			flags = 0;
1234 		again:;
1235 			fmt += strspn(fmt, skips);
1236 			switch (*fmt++) {
1237 			case '%':	/* there is no argument! */
1238 				continue;
1239 			case 'l':
1240 				flags |= 0x1;
1241 				goto again;
1242 			case '*':	/* int argument used for value */
1243 				/*
1244 				 * check if there is a positional parameter;
1245 				 * if so, just skip it; its size will be
1246 				 * correctly determined by default
1247 				 */
1248 				if (isdigit(*fmt)) {
1249 					fmt += strspn(fmt, digits);
1250 					if (*fmt == '$')
1251 						fmt++; /* skip '$' */
1252 					goto again;
1253 				}
1254 				flags |= 0x2;
1255 				(void) va_arg((*pargs).ap, int);
1256 				break;
1257 			case 'e':
1258 			case 'E':
1259 			case 'f':
1260 			case 'g':
1261 			case 'G':
1262 				if (flags & 0x1)
1263 					(void) va_arg((*pargs).ap, double);
1264 				else
1265 					(void) va_arg((*pargs).ap, double);
1266 				break;
1267 			case 's':
1268 				(void) va_arg((*pargs).ap, char *);
1269 				break;
1270 			case 'p':
1271 				(void) va_arg((*pargs).ap, void *);
1272 				break;
1273 			case 'n':
1274 				if (flags & 0x1)
1275 					(void) va_arg((*pargs).ap, long *);
1276 				else
1277 					(void) va_arg((*pargs).ap, int *);
1278 				break;
1279 			default:
1280 				if (flags & 0x1)
1281 					(void) va_arg((*pargs).ap, long int);
1282 				else
1283 					(void) va_arg((*pargs).ap, int);
1284 				break;
1285 			}
1286 			i++;
1287 			curargno++;	/* default to next in list */
1288 			if (flags & 0x2)	/* took care of *, keep going */
1289 			{
1290 				flags ^= 0x2;
1291 				goto again;
1292 			}
1293 		}
1294 
1295 		/*
1296 		 * missing specifier for parameter, assume parameter is an int
1297 		 */
1298 		if (!found && i != argno) {
1299 			(void) va_arg((*pargs).ap, int);
1300 			i++;
1301 			curargno = i;
1302 			found = 1;
1303 		}
1304 	}
1305 }
1306