xref: /titanic_41/usr/src/ucblib/libucb/port/stdio/doprnt.c (revision d24234c24aeaca4ca56ee3ac2794507968f274c4)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 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 /*
43  *	_doprnt: common code for printf, fprintf, sprintf
44  */
45 
46 #include <sys/types.h>
47 #include "file64.h"
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <ctype.h>
51 #include <stdarg.h>
52 #include <values.h>
53 #include <nan.h>
54 #include <memory.h>
55 #include <string.h>
56 #include "print.h"	/* parameters & macros for doprnt */
57 #include "stdiom.h"
58 #include <locale.h>
59 #include <stddef.h>
60 #include "_locale.h"
61 #include "libc.h"
62 
63 #define	PUT(p, n)	{ unsigned char *newbufptr; \
64 			if ((newbufptr = bufptr + (n)) > bufferend) { \
65 				_dowrite((p), (n), iop, &bufptr); \
66 			} else { \
67 				(void) memcpy(bufptr, (p), (n)); \
68 				bufptr = newbufptr; \
69 			} \
70 			}
71 #define	PAD(s, n)	{ int nn; \
72 			for (nn = (n); nn > 20; nn -= 20) \
73 				_dowrite((s), 20, iop, &bufptr); \
74 			PUT((s), nn); \
75 			}
76 
77 #define	SNLEN	5	/* Length of string used when printing a NaN */
78 
79 /* bit positions for flags used in doprnt */
80 
81 #define	LENGTH	1	/* l */
82 #define	FPLUS	2	/* + */
83 #define	FMINUS	  4	/* - */
84 #define	FBLANK	  8	/* blank */
85 #define	FSHARP	 16	/* # */
86 #define	PADZERO  32	/* padding zeroes requested via '0' */
87 #define	DOTSEEN  64	/* dot appeared in format specification */
88 #define	SUFFIX	128	/* a suffix is to appear in the output */
89 #define	RZERO	256	/* there will be trailing zeros in output */
90 #define	LZERO	512	/* there will be leading zeroes in output */
91 #define	SHORT  1024	/* h */
92 
93 /*
94  *	Positional Parameter information
95  */
96 #define	MAXARGS	30	/* max. number of args for fast positional paramters */
97 
98 /*
99  * stva_list is used to subvert C's restriction that a variable with an
100  * array type can not appear on the left hand side of an assignment operator.
101  * By putting the array inside a structure, the functionality of assigning to
102  * the whole array through a simple assignment is achieved..
103  */
104 typedef struct stva_list {
105 	va_list	ap;
106 } stva_list;
107 
108 static char _blanks[] = "                    ";
109 static char _zeroes[] = "00000000000000000000";
110 static char uc_digs[] = "0123456789ABCDEF";
111 static char lc_digs[] = "0123456789abcdef";
112 static char  lc_nan[] = "nan0x";
113 static char  uc_nan[] = "NAN0X";
114 static char  lc_inf[] = "inf";
115 static char  uc_inf[] = "INF";
116 
117 /*
118  * forward declarations
119  */
120 void _mkarglst(char *, stva_list, stva_list []);
121 void _getarg(char *, stva_list *, int);
122 static int _lowdigit(long *);
123 static void _dowrite(char *, ssize_t, FILE *, unsigned char **);
124 
125 static int
126 _lowdigit(long *valptr)
127 {	/* This function computes the decimal low-order digit of the number */
128 	/* pointed to by valptr, and returns this digit after dividing   */
129 	/* *valptr by ten.  This function is called ONLY to compute the */
130 	/* low-order digit of a long whose high-order bit is set. */
131 
132 	int lowbit = (int)(*valptr & 1);
133 	long value = (*valptr >> 1) & ~HIBITL;
134 
135 	*valptr = value / 5;
136 	return ((int)(value % 5 * 2 + lowbit + '0'));
137 }
138 
139 /* The function _dowrite carries out buffer pointer bookkeeping surrounding */
140 /* a call to fwrite.  It is called only when the end of the file output */
141 /* buffer is approached or in other unusual situations. */
142 static void
143 _dowrite(char *p, ssize_t n, FILE *iop, unsigned char **ptrptr)
144 {
145 	if (!(iop->_flag & _IOREAD)) {
146 		iop->_cnt -= (*ptrptr - iop->_ptr);
147 		iop->_ptr = *ptrptr;
148 		_bufsync(iop, _bufend(iop));
149 		(void) fwrite(p, 1, n, iop);
150 		*ptrptr = iop->_ptr;
151 	} else
152 		*ptrptr = (unsigned char *) memcpy(*ptrptr, p, n) + n;
153 }
154 
155 int
156 _doprnt(char *format, va_list in_args, FILE *iop)
157 {
158 
159 	/* bufptr is used inside of doprnt instead of iop->_ptr; */
160 	/* bufferend is a copy of _bufend(iop), if it exists.  For */
161 	/* dummy file descriptors (iop->_flag & _IOREAD), bufferend */
162 	/* may be meaningless. Dummy file descriptors are used so that */
163 	/* sprintf and vsprintf may share the _doprnt routine with the */
164 	/* rest of the printf family. */
165 
166 	unsigned char *bufptr;
167 	unsigned char *bufferend;
168 
169 	/* This variable counts output characters. */
170 	int	count = 0;
171 
172 	/* Starting and ending points for value to be printed */
173 	char	*bp;
174 	char	*p;
175 
176 	/* Field width and precision */
177 	int	width, prec;
178 
179 	/* Format code */
180 	int	fcode;
181 
182 	/* Number of padding zeroes required on the left and right */
183 	int	lzero, rzero;
184 
185 	/* Flags - bit positions defined by LENGTH, FPLUS, FMINUS, FBLANK, */
186 	/* and FSHARP are set if corresponding character is in format */
187 	/* Bit position defined by PADZERO means extra space in the field */
188 	/* should be padded with leading zeroes rather than with blanks */
189 	int	flagword;
190 
191 	/* Values are developed in this buffer */
192 	char	buf[max(MAXDIGS, 1+max(MAXFCVT+MAXEXP, MAXECVT))];
193 
194 	/* Pointer to sign, "0x", "0X", or empty */
195 	char	*prefix;
196 
197 	/* Exponent or empty */
198 	char	*suffix;
199 
200 	/* Buffer to create exponent */
201 	char	expbuf[MAXESIZ + 1];
202 
203 	/* Length of prefix and of suffix */
204 	int	prefixlength, suffixlength;
205 
206 	/* Combined length of leading zeroes, trailing zeroes, and suffix */
207 	int 	otherlength;
208 
209 	/* The value being converted, if integer */
210 	long	val;
211 
212 	/* The value being converted, if real */
213 	double	dval;
214 
215 	/* Output values from fcvt and ecvt */
216 	int	decpt, sign;
217 
218 	/* Pointer to a translate table for digits of whatever radix */
219 	char	*tab;
220 
221 	/* Work variables */
222 	int	k, lradix, mradix;
223 
224 	/* Variables used to flag an infinities and nans, resp. */
225 	/* Nan_flg is used with two purposes: to flag a NaN and */
226 	/* as the length of the string ``NAN0X'' (``nan0x'') */
227 	int	 inf_nan = 0, NaN_flg = 0;
228 
229 	/* Pointer to string "NAN0X" or "nan0x" */
230 	char	 *SNAN;
231 
232 	/* Flag for negative infinity or NaN */
233 	int neg_in = 0;
234 
235 	/* variables for positional parameters */
236 	char	*sformat = format;	/* save the beginning of the format */
237 	int	fpos = 1;		/* 1 if first positional parameter */
238 	stva_list args;		/* used to step through the argument list */
239 	stva_list sargs;
240 		/* used to save the start of the argument list */
241 	stva_list bargs;
242 		/* used to restore args if positional width or precision */
243 	stva_list arglst[MAXARGS];
244 		/*
245 		 * array giving the appropriate values for va_arg() to
246 		 * retrieve the corresponding argument:
247 		 * arglst[0] is the first argument,
248 		 * arglst[1] is the second argument, etc.
249 		 */
250 	int	starflg = 0;	/* set to 1 if * format specifier seen */
251 	/*
252 	 * Initialize args and sargs to the start of the argument list.
253 	 * Note that ANSI guarantees that the address of the first member of
254 	 * a structure will be the same as the address of the structure.
255 	 * See equivalent code in libc doprnt.c
256 	 */
257 
258 #if !(defined(__amd64) && defined(__GNUC__))	/* XX64 - fix me */
259 	va_copy(args.ap, in_args);
260 #endif
261 	sargs = args;
262 
263 	/* if first I/O to the stream get a buffer */
264 	/* Note that iop->_base should not equal 0 for sprintf and vsprintf */
265 	if (iop->_base == 0 && _findbuf(iop) == 0)
266 		return (EOF);
267 
268 	/* initialize buffer pointer and buffer end pointer */
269 	bufptr = iop->_ptr;
270 	bufferend = (iop->_flag & _IOREAD) ?
271 	    (unsigned char *)((long)bufptr | (-1L & ~HIBITL))
272 	    : _bufend(iop);
273 
274 	/*
275 	 *	The main loop -- this loop goes through one iteration
276 	 *	for each string of ordinary characters or format specification.
277 	 */
278 	for (;;) {
279 		ptrdiff_t pdiff;
280 
281 		if ((fcode = *format) != '\0' && fcode != '%') {
282 			bp = format;
283 			do {
284 				format++;
285 			} while ((fcode = *format) != '\0' && fcode != '%');
286 
287 			pdiff = format - bp;
288 				/* pdiff = no. of non-% chars */
289 			count += pdiff;
290 			PUT(bp, pdiff);
291 		}
292 		if (fcode == '\0') {  /* end of format; return */
293 			ptrdiff_t d = bufptr - iop->_ptr;
294 			iop->_cnt -= d;
295 			iop->_ptr = bufptr;
296 			if (bufptr + iop->_cnt > bufferend &&
297 			    !(iop->_flag & _IOREAD))
298 				_bufsync(iop, bufferend);
299 				/*
300 				 * in case of interrupt during last
301 				 * several lines
302 				 */
303 			if (iop->_flag & (_IONBF | _IOLBF) &&
304 			    (iop->_flag & _IONBF ||
305 			    memchr((char *)(bufptr-count), '\n', count) !=
306 			    NULL))
307 				(void) _xflsbuf(iop);
308 			return (ferror(iop) ? EOF : count);
309 		}
310 
311 		/*
312 		 *	% has been found.
313 		 *	The following switch is used to parse the format
314 		 *	specification and to perform the operation specified
315 		 *	by the format letter.  The program repeatedly goes
316 		 *	back to this switch until the format letter is
317 		 *	encountered.
318 		 */
319 		width = prefixlength = otherlength = flagword =
320 		    suffixlength = 0;
321 		format++;
322 
323 	charswitch:
324 
325 		switch (fcode = *format++) {
326 
327 		case '+':
328 			flagword |= FPLUS;
329 			goto charswitch;
330 		case '-':
331 			flagword |= FMINUS;
332 			flagword &= ~PADZERO; /* ignore 0 flag */
333 			goto charswitch;
334 		case ' ':
335 			flagword |= FBLANK;
336 			goto charswitch;
337 		case '#':
338 			flagword |= FSHARP;
339 			goto charswitch;
340 
341 		/* Scan the field width and precision */
342 		case '.':
343 			flagword |= DOTSEEN;
344 			prec = 0;
345 			goto charswitch;
346 
347 		case '*':
348 			if (isdigit(*format)) {
349 				starflg = 1;
350 				bargs = args;
351 				goto charswitch;
352 			}
353 			if (!(flagword & DOTSEEN)) {
354 				width = va_arg(args.ap, int);
355 				if (width < 0) {
356 					width = -width;
357 					flagword ^= FMINUS;
358 				}
359 			} else {
360 				prec = va_arg(args.ap, int);
361 				if (prec < 0)
362 					prec = 0;
363 			}
364 			goto charswitch;
365 
366 		case '$':
367 			{
368 			int		position;
369 			stva_list	targs;
370 			if (fpos) {
371 				_mkarglst(sformat, sargs, arglst);
372 				fpos = 0;
373 			}
374 			if (flagword & DOTSEEN) {
375 				position = prec;
376 				prec = 0;
377 			} else {
378 				position = width;
379 				width = 0;
380 			}
381 			if (position <= 0) {
382 				/* illegal position */
383 				format--;
384 				continue;
385 			}
386 			if (position <= MAXARGS) {
387 				targs = arglst[position - 1];
388 			} else {
389 				targs = arglst[MAXARGS - 1];
390 				_getarg(sformat, &targs, position);
391 			}
392 			if (!starflg)
393 				args = targs;
394 			else {
395 				starflg = 0;
396 				args = bargs;
397 				if (flagword & DOTSEEN)
398 					prec = va_arg(targs.ap, int);
399 				else
400 					width = va_arg(targs.ap, int);
401 			}
402 			goto charswitch;
403 			}
404 
405 		case '0':	/* obsolescent spec:  leading zero in width */
406 				/* means pad with leading zeros */
407 			if (!(flagword & (DOTSEEN | FMINUS)))
408 				flagword |= PADZERO;
409 			/* FALLTHROUGH */
410 		case '1':
411 		case '2':
412 		case '3':
413 		case '4':
414 		case '5':
415 		case '6':
416 		case '7':
417 		case '8':
418 		case '9':
419 			{
420 				int num = fcode - '0';
421 				while (isdigit(fcode = *format)) {
422 					num = num * 10 + fcode - '0';
423 					format++;
424 				}
425 				if (flagword & DOTSEEN)
426 					prec = num;
427 				else
428 					width = num;
429 				goto charswitch;
430 			}
431 
432 		/* Scan the length modifier */
433 		case 'l':
434 			flagword |= LENGTH;
435 			goto charswitch;
436 		case 'h':
437 			flagword |= SHORT;
438 			goto charswitch;
439 		case 'L':
440 			goto charswitch;
441 
442 		/*
443 		 *	The character addressed by format must be
444 		 *	the format letter -- there is nothing
445 		 *	left for it to be.
446 		 *
447 		 *	The status of the +, -, #, and blank
448 		 *	flags are reflected in the variable
449 		 *	"flagword".  "width" and "prec" contain
450 		 *	numbers corresponding to the digit
451 		 *	strings before and after the decimal
452 		 *	point, respectively. If there was no
453 		 *	decimal point, then flagword & DOTSEEN
454 		 *	is false and the value of prec is meaningless.
455 		 *
456 		 *	The following switch cases set things up
457 		 *	for printing.  What ultimately gets
458 		 *	printed will be padding blanks, a
459 		 *	prefix, left padding zeroes, a value,
460 		 *	right padding zeroes, a suffix, and
461 		 *	more padding blanks.  Padding blanks
462 		 *	will not appear simultaneously on both
463 		 *	the left and the right.  Each case in
464 		 *	this switch will compute the value, and
465 		 *	leave in several variables the informa-
466 		 *	tion necessary to construct what is to
467 		 *	be printed.
468 		 *
469 		 *	The prefix is a sign, a blank, "0x",
470 		 *	"0X", or null, and is addressed by
471 		 *	"prefix".
472 		 *
473 		 *	The suffix is either null or an
474 		 *	exponent, and is addressed by "suffix".
475 		 *	If there is a suffix, the flagword bit
476 		 *	SUFFIX will be set.
477 		 *
478 		 *	The value to be printed starts at "bp"
479 		 *	and continues up to and not including
480 		 *	"p".
481 		 *
482 		 *	"lzero" and "rzero" will contain the
483 		 *	number of padding zeroes required on
484 		 *	the left and right, respectively.
485 		 *	The flagword bits LZERO and RZERO tell
486 		 *	whether padding zeros are required.
487 		 *
488 		 *	The number of padding blanks, and
489 		 *	whether they go on the left or the
490 		 *	right, will be computed on exit from
491 		 *	the switch.
492 		 */
493 
494 
495 
496 
497 		/*
498 		 *	decimal fixed point representations
499 		 *
500 		 *	HIBITL is 100...000
501 		 *	binary, and is equal to	the maximum
502 		 *	negative number.
503 		 *	We assume a 2's complement machine
504 		 */
505 
506 		case 'i':
507 		case 'd':
508 			/* Fetch the argument to be printed */
509 			if (flagword & LENGTH)
510 				val = va_arg(args.ap, long);
511 			else
512 				val = va_arg(args.ap, int);
513 
514 			if (flagword & SHORT)
515 				val = (short)val;
516 
517 			/* Set buffer pointer to last digit */
518 			p = bp = buf + MAXDIGS;
519 
520 			/* If signed conversion, make sign */
521 			if (val < 0) {
522 				prefix = "-";
523 				prefixlength = 1;
524 				/*
525 				 * Negate, checking in
526 				 * advance for possible
527 				 * overflow.
528 				 */
529 				if (val != HIBITL)
530 					val = -val;
531 				else	/* number is -HIBITL; convert last */
532 					/* digit now and get positive number */
533 					*--bp = _lowdigit(&val);
534 			} else if (flagword & FPLUS) {
535 				prefix = "+";
536 				prefixlength = 1;
537 			} else if (flagword & FBLANK) {
538 				prefix = " ";
539 				prefixlength = 1;
540 			}
541 
542 		decimal:
543 			{
544 				long qval = val;
545 				long saveq;
546 
547 				if (qval <= 9) {
548 					if (qval != 0 || !(flagword & DOTSEEN))
549 						*--bp = (char)(qval + '0');
550 				} else {
551 					do {
552 						saveq = qval;
553 						qval /= 10;
554 						*--bp = (char)(saveq -
555 						    qval * 10 + '0');
556 					} while (qval > 9);
557 					*--bp = (char)(qval + '0');
558 					pdiff = (ptrdiff_t)saveq;
559 				}
560 			}
561 
562 			/* Calculate minimum padding zero requirement */
563 			if (flagword & DOTSEEN) {
564 				int leadzeroes = prec - (int)(p - bp);
565 				if (leadzeroes > 0) {
566 					otherlength = lzero = leadzeroes;
567 					flagword |= LZERO;
568 				}
569 			}
570 
571 			break;
572 
573 		case 'u':
574 			/* Fetch the argument to be printed */
575 			if (flagword & LENGTH)
576 				val = va_arg(args.ap, long);
577 			else
578 				val = va_arg(args.ap, unsigned);
579 
580 			if (flagword & SHORT)
581 				val = (unsigned short)val;
582 
583 			p = bp = buf + MAXDIGS;
584 
585 			if (val & HIBITL)
586 				*--bp = _lowdigit(&val);
587 
588 			goto decimal;
589 
590 		/*
591 		 *	non-decimal fixed point representations
592 		 *	for radix equal to a power of two
593 		 *
594 		 *	"mradix" is one less than the radix for the conversion.
595 		 *	"lradix" is one less than the base 2 log
596 		 *	of the radix for the conversion. Conversion is unsigned.
597 		 *	HIBITL is 100...000
598 		 *	binary, and is equal to	the maximum
599 		 *	negative number.
600 		 *	We assume a 2's complement machine
601 		 */
602 
603 		case 'o':
604 			mradix = 7;
605 			lradix = 2;
606 			goto fixed;
607 
608 		case 'X':
609 		case 'x':
610 		case 'p':
611 			mradix = 15;
612 			lradix = 3;
613 
614 		fixed:
615 			/* Fetch the argument to be printed */
616 			if (flagword & LENGTH)
617 				val = va_arg(args.ap, long);
618 			else
619 				val = va_arg(args.ap, unsigned);
620 
621 			if (flagword & SHORT)
622 				val = (unsigned short)val;
623 
624 			/* Set translate table for digits */
625 			tab = (fcode == 'X') ? uc_digs : lc_digs;
626 
627 			/* Entry point when printing a double which is a NaN */
628 		put_pc:
629 			/* Develop the digits of the value */
630 			p = bp = buf + MAXDIGS;
631 			{
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 			{
744 				int rz = prec;
745 				for (; rz > 0 && *bp != '\0'; --rz)
746 					*p++ = *bp++;
747 				if (rz > 0) {
748 					otherlength = rzero = rz;
749 					flagword |= RZERO;
750 				}
751 			}
752 
753 			bp = &buf[0];
754 
755 			/* Create the exponent */
756 			*(suffix = &expbuf[MAXESIZ]) = '\0';
757 			if (dval != 0) {
758 				int nn = decpt - 1;
759 				if (nn < 0)
760 					nn = -nn;
761 				for (; nn > 9; nn /= 10)
762 					*--suffix = todigit(nn % 10);
763 				*--suffix = todigit(nn);
764 			}
765 
766 			/* Prepend leading zeroes to the exponent */
767 			while (suffix > &expbuf[MAXESIZ - 2])
768 				*--suffix = '0';
769 
770 			/* Put in the exponent sign */
771 			*--suffix = (decpt > 0 || dval == 0) ? '+' : '-';
772 
773 			/* Put in the e */
774 			*--suffix = isupper(fcode) ? 'E'  : 'e';
775 
776 			/* compute size of suffix */
777 			otherlength += (suffixlength =
778 			    (int)(&expbuf[MAXESIZ] - suffix));
779 			flagword |= SUFFIX;
780 
781 			break;
782 
783 		case 'f':
784 			/*
785 			 * F-format floating point.  This is a
786 			 * good deal less simple than E-format.
787 			 * The overall strategy will be to call
788 			 * fcvt, reformat its result into buf,
789 			 * and calculate how many trailing
790 			 * zeroes will be required.  There will
791 			 * never be any leading zeroes needed.
792 			 */
793 
794 			/* Establish default precision */
795 			if (!(flagword & DOTSEEN))
796 				prec = 6;
797 
798 			/* Fetch the value */
799 			dval = va_arg(args.ap, double);
800 
801 			/* Check for NaNs and Infinities  */
802 			if (IsNANorINF(dval)) {
803 				if (IsINF(dval)) {
804 					if (IsNegNAN(dval))
805 						neg_in = 1;
806 					inf_nan = 1;
807 					bp = lc_inf;
808 					p = bp + 3;
809 					break;
810 				} else {
811 					if (IsNegNAN(dval))
812 						neg_in = 1;
813 					inf_nan = 1;
814 					val  = GETNaNPC(dval);
815 					NaN_flg = SNLEN;
816 					mradix = 15;
817 					lradix = 3;
818 					tab =  lc_digs;
819 					SNAN = lc_nan;
820 					goto put_pc;
821 				}
822 			}
823 			/* Do the conversion */
824 			bp = fcvt(dval, min(prec, MAXFCVT), &decpt, &sign);
825 
826 			/* Determine the prefix */
827 		f_merge:
828 			if (sign) {
829 				prefix = "-";
830 				prefixlength = 1;
831 			} else if (flagword & FPLUS) {
832 				prefix = "+";
833 				prefixlength = 1;
834 			} else if (flagword & FBLANK) {
835 				prefix = " ";
836 				prefixlength = 1;
837 			}
838 
839 			/* Initialize buffer pointer */
840 			p = &buf[0];
841 			{
842 				int nn = decpt;
843 
844 				/* Emit the digits before the decimal point */
845 				k = 0;
846 				do {
847 					*p++ = (nn <= 0 || *bp == '\0' ||
848 					    k >= MAXFSIG) ?
849 					    '0' : (k++, *bp++);
850 				} while (--nn > 0);
851 
852 				/* Decide whether we need a decimal point */
853 				if ((flagword & FSHARP) || prec > 0)
854 					*p++ = _numeric[0];
855 
856 				/* Digits (if any) after the decimal point */
857 				nn = min(prec, MAXFCVT);
858 				if (prec > nn) {
859 					flagword |= RZERO;
860 					otherlength = rzero = prec - nn;
861 				}
862 				while (--nn >= 0)
863 					*p++ = (++decpt <= 0 || *bp == '\0' ||
864 					    k >= MAXFSIG) ?
865 					    '0' : (k++, *bp++);
866 			}
867 
868 			bp = &buf[0];
869 
870 			break;
871 
872 		case 'G':
873 		case 'g':
874 			/*
875 			 * g-format.  We play around a bit
876 			 * and then jump into e or f, as needed.
877 			 */
878 
879 			/* Establish default precision */
880 			if (!(flagword & DOTSEEN))
881 				prec = 6;
882 			else if (prec == 0)
883 				prec = 1;
884 
885 			/* Fetch the value */
886 			dval = va_arg(args.ap, double);
887 
888 			/* Check for NaN and Infinities  */
889 			if (IsNANorINF(dval)) {
890 				if (IsINF(dval)) {
891 					if (IsNegNAN(dval))
892 						neg_in = 1;
893 					bp = (fcode == 'G') ? uc_inf : lc_inf;
894 					p = bp + 3;
895 					inf_nan = 1;
896 					break;
897 				} else {
898 					if (IsNegNAN(dval))
899 						neg_in = 1;
900 					inf_nan = 1;
901 					val  = GETNaNPC(dval);
902 					NaN_flg = SNLEN;
903 					mradix = 15;
904 					lradix = 3;
905 					if (fcode == 'G') {
906 						SNAN = uc_nan;
907 						tab = uc_digs;
908 					} else {
909 						SNAN = lc_nan;
910 						tab =  lc_digs;
911 					}
912 					goto put_pc;
913 				}
914 			}
915 
916 			/* Do the conversion */
917 			bp = ecvt(dval, min(prec, MAXECVT), &decpt, &sign);
918 			if (dval == 0)
919 				decpt = 1;
920 			{
921 				int kk = prec;
922 				size_t sz;
923 
924 				if (!(flagword & FSHARP)) {
925 					sz = strlen(bp);
926 					if (sz < kk)
927 						kk = (int)sz;
928 					while (kk >= 1 && bp[kk-1] == '0')
929 						--kk;
930 				}
931 
932 				if (decpt < -3 || decpt > prec) {
933 					prec = kk - 1;
934 					goto e_merge;
935 				}
936 				prec = kk - decpt;
937 				goto f_merge;
938 			}
939 
940 		case '%':
941 			buf[0] = (char)fcode;
942 			goto c_merge;
943 
944 		case 'c':
945 			buf[0] = va_arg(args.ap, int);
946 		c_merge:
947 			p = (bp = &buf[0]) + 1;
948 			break;
949 
950 		case 's':
951 			bp = va_arg(args.ap, char *);
952 			if (!(flagword & DOTSEEN))
953 				p = bp + strlen(bp);
954 			else { /* a strnlen function would  be useful here! */
955 				char *qp = bp;
956 				while (*qp++ != '\0' && --prec >= 0)
957 					;
958 				p = qp - 1;
959 			}
960 			break;
961 
962 		case 'n':
963 			{
964 				if (flagword & LENGTH) {
965 					long *svcount;
966 					svcount = va_arg(args.ap, long *);
967 					*svcount = count;
968 				} else if (flagword & SHORT) {
969 					short *svcount;
970 					svcount = va_arg(args.ap, short *);
971 					*svcount = (short)count;
972 				} else {
973 					int *svcount;
974 					svcount = va_arg(args.ap, int *);
975 					*svcount = count;
976 				}
977 				continue;
978 			}
979 
980 		default: /* this is technically an error; what we do is to */
981 			/* back up the format pointer to the offending char */
982 			/* and continue with the format scan */
983 			format--;
984 			continue;
985 
986 		}
987 
988 		if (inf_nan) {
989 			if (neg_in) {
990 				prefix = "-";
991 				prefixlength = 1;
992 				neg_in = 0;
993 			} else if (flagword & FPLUS) {
994 				prefix = "+";
995 				prefixlength = 1;
996 			} else if (flagword & FBLANK) {
997 				prefix = " ";
998 				prefixlength = 1;
999 			}
1000 			inf_nan = 0;
1001 		}
1002 
1003 		/* Calculate number of padding blanks */
1004 		k = (int)(pdiff = p - bp) + prefixlength + otherlength +
1005 		    NaN_flg;
1006 		if (width <= k)
1007 			count += k;
1008 		else {
1009 			count += width;
1010 
1011 			/* Set up for padding zeroes if requested */
1012 			/* Otherwise emit padding blanks unless output is */
1013 			/* to be left-justified.  */
1014 
1015 			if (flagword & PADZERO) {
1016 				if (!(flagword & LZERO)) {
1017 					flagword |= LZERO;
1018 					lzero = width - k;
1019 				}
1020 				else
1021 					lzero += width - k;
1022 				k = width; /* cancel padding blanks */
1023 			} else
1024 				/* Blanks on left if required */
1025 				if (!(flagword & FMINUS))
1026 					PAD(_blanks, width - k);
1027 		}
1028 
1029 		/* Prefix, if any */
1030 		if (prefixlength != 0)
1031 			PUT(prefix, prefixlength);
1032 
1033 		/* If value is NaN, put string NaN */
1034 		if (NaN_flg) {
1035 			PUT(SNAN, SNLEN);
1036 			NaN_flg = 0;
1037 		}
1038 
1039 		/* Zeroes on the left */
1040 		if (flagword & LZERO)
1041 			PAD(_zeroes, lzero);
1042 
1043 		/* The value itself */
1044 		if (pdiff > 0)
1045 			PUT(bp, pdiff);
1046 
1047 		if (flagword & (RZERO | SUFFIX | FMINUS)) {
1048 			/* Zeroes on the right */
1049 			if (flagword & RZERO)
1050 				PAD(_zeroes, rzero);
1051 
1052 			/* The suffix */
1053 			if (flagword & SUFFIX)
1054 				PUT(suffix, suffixlength);
1055 
1056 			/* Blanks on the right if required */
1057 			if (flagword & FMINUS && width > k)
1058 				PAD(_blanks, width - k);
1059 		}
1060 	}
1061 }
1062 
1063 /*
1064  * This function initializes arglst, to contain the appropriate va_list values
1065  * for the first MAXARGS arguments.
1066  */
1067 void
1068 _mkarglst(char *fmt, stva_list args, stva_list arglst[])
1069 {
1070 	static char digits[] = "01234567890", skips[] = "# +-.0123456789hL$";
1071 
1072 	enum types {INT = 1, LONG, CHAR_PTR, DOUBLE, LONG_DOUBLE, VOID_PTR,
1073 		LONG_PTR, INT_PTR};
1074 	enum types typelst[MAXARGS], curtype;
1075 	int maxnum, n, curargno, flags;
1076 
1077 	/*
1078 	 * Algorithm	1. set all argument types to zero.
1079 	 *		2. walk through fmt putting arg types in typelst[].
1080 	 *		3. walk through args using va_arg(args.ap, typelst[n])
1081 	 *		   and set arglst[] to the appropriate values.
1082 	 * Assumptions:	Cannot use %*$... to specify variable position.
1083 	 */
1084 
1085 	(void) memset((void *)typelst, 0, sizeof (typelst));
1086 	maxnum = -1;
1087 	curargno = 0;
1088 	while ((fmt = strchr(fmt, '%')) != 0) {
1089 		size_t sz;
1090 
1091 		fmt++;	/* skip % */
1092 		if (fmt[sz = strspn(fmt, digits)] == '$') {
1093 			curargno = atoi(fmt) - 1;
1094 				/* convert to zero base */
1095 			if (curargno < 0)
1096 				continue;
1097 			fmt += sz + 1;
1098 		}
1099 		flags = 0;
1100 	again:;
1101 		fmt += strspn(fmt, skips);
1102 		switch (*fmt++) {
1103 		case '%':	/* there is no argument! */
1104 			continue;
1105 		case 'l':
1106 			flags |= 0x1;
1107 			goto again;
1108 		case '*':	/* int argument used for value */
1109 			/* check if there is a positional parameter */
1110 			if (isdigit(*fmt)) {
1111 				int	targno;
1112 				targno = atoi(fmt) - 1;
1113 				fmt += strspn(fmt, digits);
1114 				if (*fmt == '$')
1115 					fmt++; /* skip '$' */
1116 				if (targno >= 0 && targno < MAXARGS) {
1117 					typelst[targno] = INT;
1118 					if (maxnum < targno)
1119 						maxnum = targno;
1120 				}
1121 				goto again;
1122 			}
1123 			flags |= 0x2;
1124 			curtype = INT;
1125 			break;
1126 		case 'e':
1127 		case 'E':
1128 		case 'f':
1129 		case 'g':
1130 		case 'G':
1131 			curtype = DOUBLE;
1132 			break;
1133 		case 's':
1134 			curtype = CHAR_PTR;
1135 			break;
1136 		case 'p':
1137 			curtype = VOID_PTR;
1138 			break;
1139 		case 'n':
1140 			if (flags & 0x1)
1141 				curtype = LONG_PTR;
1142 			else
1143 				curtype = INT_PTR;
1144 			break;
1145 		default:
1146 			if (flags & 0x1)
1147 				curtype = LONG;
1148 			else
1149 				curtype = INT;
1150 			break;
1151 		}
1152 		if (curargno >= 0 && curargno < MAXARGS) {
1153 			typelst[curargno] = curtype;
1154 			if (maxnum < curargno)
1155 				maxnum = curargno;
1156 		}
1157 		curargno++;	/* default to next in list */
1158 		if (flags & 0x2)	/* took care of *, keep going */
1159 		{
1160 			flags ^= 0x2;
1161 			goto again;
1162 		}
1163 	}
1164 	for (n = 0; n <= maxnum; n++) {
1165 		arglst[n] = args;
1166 		if (typelst[n] == 0)
1167 			typelst[n] = INT;
1168 
1169 		switch (typelst[n]) {
1170 		case INT:
1171 			(void) va_arg(args.ap, int);
1172 			break;
1173 		case LONG:
1174 			(void) va_arg(args.ap, long);
1175 			break;
1176 		case CHAR_PTR:
1177 			(void) va_arg(args.ap, char *);
1178 			break;
1179 		case DOUBLE:
1180 			(void) va_arg(args.ap, double);
1181 			break;
1182 		case LONG_DOUBLE:
1183 			(void) va_arg(args.ap, double);
1184 			break;
1185 		case VOID_PTR:
1186 			(void) va_arg(args.ap, void *);
1187 			break;
1188 		case LONG_PTR:
1189 			(void) va_arg(args.ap, long *);
1190 			break;
1191 		case INT_PTR:
1192 			(void) va_arg(args.ap, int *);
1193 			break;
1194 		}
1195 	}
1196 }
1197 
1198 /*
1199  * This function is used to find the va_list value for arguments whose
1200  * position is greater than MAXARGS.  This function is slow, so hopefully
1201  * MAXARGS will be big enough so that this function need only be called in
1202  * unusual circumstances.
1203  * pargs is assumed to contain the value of arglst[MAXARGS - 1].
1204  */
1205 void
1206 _getarg(char *fmt, stva_list *pargs, int argno)
1207 {
1208 	static char digits[] = "01234567890", skips[] = "# +-.0123456789h$";
1209 	int i, curargno, flags;
1210 	size_t n;
1211 	char	*sfmt = fmt;
1212 	int	found = 1;
1213 
1214 	i = MAXARGS;
1215 	curargno = 1;
1216 	while (found) {
1217 		fmt = sfmt;
1218 		found = 0;
1219 		while ((i != argno) && (fmt = strchr(fmt, '%')) != 0) {
1220 			fmt++;	/* skip % */
1221 			if (fmt[n = strspn(fmt, digits)] == '$') {
1222 				curargno = atoi(fmt);
1223 				if (curargno <= 0)
1224 					continue;
1225 				fmt += n + 1;
1226 			}
1227 
1228 			/* find conversion specifier for next argument */
1229 			if (i != curargno) {
1230 				curargno++;
1231 				continue;
1232 			} else
1233 				found = 1;
1234 			flags = 0;
1235 		again:;
1236 			fmt += strspn(fmt, skips);
1237 			switch (*fmt++) {
1238 			case '%':	/* there is no argument! */
1239 				continue;
1240 			case 'l':
1241 				flags |= 0x1;
1242 				goto again;
1243 			case '*':	/* int argument used for value */
1244 				/*
1245 				 * check if there is a positional parameter;
1246 				 * if so, just skip it; its size will be
1247 				 * correctly determined by default
1248 				 */
1249 				if (isdigit(*fmt)) {
1250 					fmt += strspn(fmt, digits);
1251 					if (*fmt == '$')
1252 						fmt++; /* skip '$' */
1253 					goto again;
1254 				}
1255 				flags |= 0x2;
1256 				(void) va_arg((*pargs).ap, int);
1257 				break;
1258 			case 'e':
1259 			case 'E':
1260 			case 'f':
1261 			case 'g':
1262 			case 'G':
1263 				if (flags & 0x1)
1264 					(void) va_arg((*pargs).ap, double);
1265 				else
1266 					(void) va_arg((*pargs).ap, double);
1267 				break;
1268 			case 's':
1269 				(void) va_arg((*pargs).ap, char *);
1270 				break;
1271 			case 'p':
1272 				(void) va_arg((*pargs).ap, void *);
1273 				break;
1274 			case 'n':
1275 				if (flags & 0x1)
1276 					(void) va_arg((*pargs).ap, long *);
1277 				else
1278 					(void) va_arg((*pargs).ap, int *);
1279 				break;
1280 			default:
1281 				if (flags & 0x1)
1282 					(void) va_arg((*pargs).ap, long int);
1283 				else
1284 					(void) va_arg((*pargs).ap, int);
1285 				break;
1286 			}
1287 			i++;
1288 			curargno++;	/* default to next in list */
1289 			if (flags & 0x2)	/* took care of *, keep going */
1290 			{
1291 				flags ^= 0x2;
1292 				goto again;
1293 			}
1294 		}
1295 
1296 		/*
1297 		 * missing specifier for parameter, assume parameter is an int
1298 		 */
1299 		if (!found && i != argno) {
1300 			(void) va_arg((*pargs).ap, int);
1301 			i++;
1302 			curargno = i;
1303 			found = 1;
1304 		}
1305 	}
1306 }
1307