xref: /illumos-gate/usr/src/ucblib/libucb/port/stdio/doprnt.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 /*
41  *	_doprnt: common code for printf, fprintf, sprintf
42  */
43 
44 #include <sys/types.h>
45 #include "file64.h"
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <ctype.h>
49 #include <stdarg.h>
50 #include <values.h>
51 #include <nan.h>
52 #include <memory.h>
53 #include <string.h>
54 #include "print.h"	/* parameters & macros for doprnt */
55 #include "stdiom.h"
56 #include <locale.h>
57 #include <stddef.h>
58 #include "_locale.h"
59 #include "libc.h"
60 
61 #define	PUT(p, n)	{ unsigned char *newbufptr; \
62 			if ((newbufptr = bufptr + (n)) > bufferend) { \
63 				_dowrite((p), (n), iop, &bufptr); \
64 			} else { \
65 				(void) memcpy(bufptr, (p), (n)); \
66 				bufptr = newbufptr; \
67 			} \
68 			}
69 #define	PAD(s, n)	{ int nn; \
70 			for (nn = (n); nn > 20; nn -= 20) \
71 				_dowrite((s), 20, iop, &bufptr); \
72 			PUT((s), nn); \
73 			}
74 
75 #define	SNLEN	5	/* Length of string used when printing a NaN */
76 
77 /* bit positions for flags used in doprnt */
78 
79 #define	LENGTH	1	/* l */
80 #define	FPLUS	2	/* + */
81 #define	FMINUS	  4	/* - */
82 #define	FBLANK	  8	/* blank */
83 #define	FSHARP	 16	/* # */
84 #define	PADZERO  32	/* padding zeroes requested via '0' */
85 #define	DOTSEEN  64	/* dot appeared in format specification */
86 #define	SUFFIX	128	/* a suffix is to appear in the output */
87 #define	RZERO	256	/* there will be trailing zeros in output */
88 #define	LZERO	512	/* there will be leading zeroes in output */
89 #define	SHORT  1024	/* h */
90 
91 /*
92  *	Positional Parameter information
93  */
94 #define	MAXARGS	30	/* max. number of args for fast positional paramters */
95 
96 /*
97  * stva_list is used to subvert C's restriction that a variable with an
98  * array type can not appear on the left hand side of an assignment operator.
99  * By putting the array inside a structure, the functionality of assigning to
100  * the whole array through a simple assignment is achieved..
101  */
102 typedef struct stva_list {
103 	va_list	ap;
104 } stva_list;
105 
106 static char _blanks[] = "                    ";
107 static char _zeroes[] = "00000000000000000000";
108 static char uc_digs[] = "0123456789ABCDEF";
109 static char lc_digs[] = "0123456789abcdef";
110 static char  lc_nan[] = "nan0x";
111 static char  uc_nan[] = "NAN0X";
112 static char  lc_inf[] = "inf";
113 static char  uc_inf[] = "INF";
114 
115 /*
116  * forward declarations
117  */
118 void _mkarglst(char *, stva_list, stva_list []);
119 void _getarg(char *, stva_list *, int);
120 static int _lowdigit(long *);
121 static void _dowrite(char *, ssize_t, FILE *, unsigned char **);
122 
123 static int
124 _lowdigit(long *valptr)
125 {	/* This function computes the decimal low-order digit of the number */
126 	/* pointed to by valptr, and returns this digit after dividing   */
127 	/* *valptr by ten.  This function is called ONLY to compute the */
128 	/* low-order digit of a long whose high-order bit is set. */
129 
130 	int lowbit = (int)(*valptr & 1);
131 	long value = (*valptr >> 1) & ~HIBITL;
132 
133 	*valptr = value / 5;
134 	return ((int)(value % 5 * 2 + lowbit + '0'));
135 }
136 
137 /* The function _dowrite carries out buffer pointer bookkeeping surrounding */
138 /* a call to fwrite.  It is called only when the end of the file output */
139 /* buffer is approached or in other unusual situations. */
140 static void
141 _dowrite(char *p, ssize_t n, FILE *iop, unsigned char **ptrptr)
142 {
143 	if (!(iop->_flag & _IOREAD)) {
144 		iop->_cnt -= (*ptrptr - iop->_ptr);
145 		iop->_ptr = *ptrptr;
146 		_bufsync(iop, _bufend(iop));
147 		(void) fwrite(p, 1, n, iop);
148 		*ptrptr = iop->_ptr;
149 	} else
150 		*ptrptr = (unsigned char *) memcpy(*ptrptr, p, n) + n;
151 }
152 
153 int
154 _doprnt(char *format, va_list in_args, FILE *iop)
155 {
156 
157 	/* bufptr is used inside of doprnt instead of iop->_ptr; */
158 	/* bufferend is a copy of _bufend(iop), if it exists.  For */
159 	/* dummy file descriptors (iop->_flag & _IOREAD), bufferend */
160 	/* may be meaningless. Dummy file descriptors are used so that */
161 	/* sprintf and vsprintf may share the _doprnt routine with the */
162 	/* rest of the printf family. */
163 
164 	unsigned char *bufptr;
165 	unsigned char *bufferend;
166 
167 	/* This variable counts output characters. */
168 	int	count = 0;
169 
170 	/* Starting and ending points for value to be printed */
171 	char	*bp;
172 	char	*p;
173 
174 	/* Field width and precision */
175 	int	width, prec;
176 
177 	/* Format code */
178 	int	fcode;
179 
180 	/* Number of padding zeroes required on the left and right */
181 	int	lzero, rzero;
182 
183 	/* Flags - bit positions defined by LENGTH, FPLUS, FMINUS, FBLANK, */
184 	/* and FSHARP are set if corresponding character is in format */
185 	/* Bit position defined by PADZERO means extra space in the field */
186 	/* should be padded with leading zeroes rather than with blanks */
187 	int	flagword;
188 
189 	/* Values are developed in this buffer */
190 	char	buf[max(MAXDIGS, 1+max(MAXFCVT+MAXEXP, MAXECVT))];
191 
192 	/* Pointer to sign, "0x", "0X", or empty */
193 	char	*prefix;
194 
195 	/* Exponent or empty */
196 	char	*suffix;
197 
198 	/* Buffer to create exponent */
199 	char	expbuf[MAXESIZ + 1];
200 
201 	/* Length of prefix and of suffix */
202 	int	prefixlength, suffixlength;
203 
204 	/* Combined length of leading zeroes, trailing zeroes, and suffix */
205 	int 	otherlength;
206 
207 	/* The value being converted, if integer */
208 	long	val;
209 
210 	/* The value being converted, if real */
211 	double	dval;
212 
213 	/* Output values from fcvt and ecvt */
214 	int	decpt, sign;
215 
216 	/* Pointer to a translate table for digits of whatever radix */
217 	char	*tab;
218 
219 	/* Work variables */
220 	int	k, lradix, mradix;
221 
222 	/* Variables used to flag an infinities and nans, resp. */
223 	/* Nan_flg is used with two purposes: to flag a NaN and */
224 	/* as the length of the string ``NAN0X'' (``nan0x'') */
225 	int	 inf_nan = 0, NaN_flg = 0;
226 
227 	/* Pointer to string "NAN0X" or "nan0x" */
228 	char	 *SNAN;
229 
230 	/* Flag for negative infinity or NaN */
231 	int neg_in = 0;
232 
233 	/* variables for positional parameters */
234 	char	*sformat = format;	/* save the beginning of the format */
235 	int	fpos = 1;		/* 1 if first positional parameter */
236 	stva_list args;		/* used to step through the argument list */
237 	stva_list sargs;
238 		/* used to save the start of the argument list */
239 	stva_list bargs;
240 		/* used to restore args if positional width or precision */
241 	stva_list arglst[MAXARGS];
242 		/*
243 		 * array giving the appropriate values for va_arg() to
244 		 * retrieve the corresponding argument:
245 		 * arglst[0] is the first argument,
246 		 * arglst[1] is the second argument, etc.
247 		 */
248 	int	starflg = 0;	/* set to 1 if * format specifier seen */
249 	/*
250 	 * Initialize args and sargs to the start of the argument list.
251 	 * Note that ANSI guarantees that the address of the first member of
252 	 * a structure will be the same as the address of the structure.
253 	 * See equivalent code in libc doprnt.c
254 	 */
255 
256 #if !(defined(__amd64) && defined(__GNUC__))	/* XX64 - fix me */
257 	va_copy(args.ap, in_args);
258 #endif
259 	sargs = args;
260 
261 	/* if first I/O to the stream get a buffer */
262 	/* Note that iop->_base should not equal 0 for sprintf and vsprintf */
263 	if (iop->_base == 0 && _findbuf(iop) == 0)
264 		return (EOF);
265 
266 	/* initialize buffer pointer and buffer end pointer */
267 	bufptr = iop->_ptr;
268 	bufferend = (iop->_flag & _IOREAD) ?
269 	    (unsigned char *)((long)bufptr | (-1L & ~HIBITL))
270 	    : _bufend(iop);
271 
272 	/*
273 	 *	The main loop -- this loop goes through one iteration
274 	 *	for each string of ordinary characters or format specification.
275 	 */
276 	for (;;) {
277 		ptrdiff_t pdiff;
278 
279 		if ((fcode = *format) != '\0' && fcode != '%') {
280 			bp = format;
281 			do {
282 				format++;
283 			} while ((fcode = *format) != '\0' && fcode != '%');
284 
285 			pdiff = format - bp;
286 				/* pdiff = no. of non-% chars */
287 			count += pdiff;
288 			PUT(bp, pdiff);
289 		}
290 		if (fcode == '\0') {  /* end of format; return */
291 			ptrdiff_t d = bufptr - iop->_ptr;
292 			iop->_cnt -= d;
293 			iop->_ptr = bufptr;
294 			if (bufptr + iop->_cnt > bufferend &&
295 			    !(iop->_flag & _IOREAD))
296 				_bufsync(iop, bufferend);
297 				/*
298 				 * in case of interrupt during last
299 				 * several lines
300 				 */
301 			if (iop->_flag & (_IONBF | _IOLBF) &&
302 			    (iop->_flag & _IONBF ||
303 			    memchr((char *)(bufptr-count), '\n', count) !=
304 			    NULL))
305 				(void) _xflsbuf(iop);
306 			return (ferror(iop) ? EOF : count);
307 		}
308 
309 		/*
310 		 *	% has been found.
311 		 *	The following switch is used to parse the format
312 		 *	specification and to perform the operation specified
313 		 *	by the format letter.  The program repeatedly goes
314 		 *	back to this switch until the format letter is
315 		 *	encountered.
316 		 */
317 		width = prefixlength = otherlength = flagword =
318 		    suffixlength = 0;
319 		format++;
320 
321 	charswitch:
322 
323 		switch (fcode = *format++) {
324 
325 		case '+':
326 			flagword |= FPLUS;
327 			goto charswitch;
328 		case '-':
329 			flagword |= FMINUS;
330 			flagword &= ~PADZERO; /* ignore 0 flag */
331 			goto charswitch;
332 		case ' ':
333 			flagword |= FBLANK;
334 			goto charswitch;
335 		case '#':
336 			flagword |= FSHARP;
337 			goto charswitch;
338 
339 		/* Scan the field width and precision */
340 		case '.':
341 			flagword |= DOTSEEN;
342 			prec = 0;
343 			goto charswitch;
344 
345 		case '*':
346 			if (isdigit(*format)) {
347 				starflg = 1;
348 				bargs = args;
349 				goto charswitch;
350 			}
351 			if (!(flagword & DOTSEEN)) {
352 				width = va_arg(args.ap, int);
353 				if (width < 0) {
354 					width = -width;
355 					flagword ^= FMINUS;
356 				}
357 			} else {
358 				prec = va_arg(args.ap, int);
359 				if (prec < 0)
360 					prec = 0;
361 			}
362 			goto charswitch;
363 
364 		case '$':
365 			{
366 			int		position;
367 			stva_list	targs;
368 			if (fpos) {
369 				_mkarglst(sformat, sargs, arglst);
370 				fpos = 0;
371 			}
372 			if (flagword & DOTSEEN) {
373 				position = prec;
374 				prec = 0;
375 			} else {
376 				position = width;
377 				width = 0;
378 			}
379 			if (position <= 0) {
380 				/* illegal position */
381 				format--;
382 				continue;
383 			}
384 			if (position <= MAXARGS) {
385 				targs = arglst[position - 1];
386 			} else {
387 				targs = arglst[MAXARGS - 1];
388 				_getarg(sformat, &targs, position);
389 			}
390 			if (!starflg)
391 				args = targs;
392 			else {
393 				starflg = 0;
394 				args = bargs;
395 				if (flagword & DOTSEEN)
396 					prec = va_arg(targs.ap, int);
397 				else
398 					width = va_arg(targs.ap, int);
399 			}
400 			goto charswitch;
401 			}
402 
403 		case '0':	/* obsolescent spec:  leading zero in width */
404 				/* means pad with leading zeros */
405 			if (!(flagword & (DOTSEEN | FMINUS)))
406 				flagword |= PADZERO;
407 			/* FALLTHROUGH */
408 		case '1':
409 		case '2':
410 		case '3':
411 		case '4':
412 		case '5':
413 		case '6':
414 		case '7':
415 		case '8':
416 		case '9':
417 			{
418 				int num = fcode - '0';
419 				while (isdigit(fcode = *format)) {
420 					num = num * 10 + fcode - '0';
421 					format++;
422 				}
423 				if (flagword & DOTSEEN)
424 					prec = num;
425 				else
426 					width = num;
427 				goto charswitch;
428 			}
429 
430 		/* Scan the length modifier */
431 		case 'l':
432 			flagword |= LENGTH;
433 			goto charswitch;
434 		case 'h':
435 			flagword |= SHORT;
436 			goto charswitch;
437 		case 'L':
438 			goto charswitch;
439 
440 		/*
441 		 *	The character addressed by format must be
442 		 *	the format letter -- there is nothing
443 		 *	left for it to be.
444 		 *
445 		 *	The status of the +, -, #, and blank
446 		 *	flags are reflected in the variable
447 		 *	"flagword".  "width" and "prec" contain
448 		 *	numbers corresponding to the digit
449 		 *	strings before and after the decimal
450 		 *	point, respectively. If there was no
451 		 *	decimal point, then flagword & DOTSEEN
452 		 *	is false and the value of prec is meaningless.
453 		 *
454 		 *	The following switch cases set things up
455 		 *	for printing.  What ultimately gets
456 		 *	printed will be padding blanks, a
457 		 *	prefix, left padding zeroes, a value,
458 		 *	right padding zeroes, a suffix, and
459 		 *	more padding blanks.  Padding blanks
460 		 *	will not appear simultaneously on both
461 		 *	the left and the right.  Each case in
462 		 *	this switch will compute the value, and
463 		 *	leave in several variables the informa-
464 		 *	tion necessary to construct what is to
465 		 *	be printed.
466 		 *
467 		 *	The prefix is a sign, a blank, "0x",
468 		 *	"0X", or null, and is addressed by
469 		 *	"prefix".
470 		 *
471 		 *	The suffix is either null or an
472 		 *	exponent, and is addressed by "suffix".
473 		 *	If there is a suffix, the flagword bit
474 		 *	SUFFIX will be set.
475 		 *
476 		 *	The value to be printed starts at "bp"
477 		 *	and continues up to and not including
478 		 *	"p".
479 		 *
480 		 *	"lzero" and "rzero" will contain the
481 		 *	number of padding zeroes required on
482 		 *	the left and right, respectively.
483 		 *	The flagword bits LZERO and RZERO tell
484 		 *	whether padding zeros are required.
485 		 *
486 		 *	The number of padding blanks, and
487 		 *	whether they go on the left or the
488 		 *	right, will be computed on exit from
489 		 *	the switch.
490 		 */
491 
492 
493 
494 
495 		/*
496 		 *	decimal fixed point representations
497 		 *
498 		 *	HIBITL is 100...000
499 		 *	binary, and is equal to	the maximum
500 		 *	negative number.
501 		 *	We assume a 2's complement machine
502 		 */
503 
504 		case 'i':
505 		case 'd':
506 			/* Fetch the argument to be printed */
507 			if (flagword & LENGTH)
508 				val = va_arg(args.ap, long);
509 			else
510 				val = va_arg(args.ap, int);
511 
512 			if (flagword & SHORT)
513 				val = (short)val;
514 
515 			/* Set buffer pointer to last digit */
516 			p = bp = buf + MAXDIGS;
517 
518 			/* If signed conversion, make sign */
519 			if (val < 0) {
520 				prefix = "-";
521 				prefixlength = 1;
522 				/*
523 				 * Negate, checking in
524 				 * advance for possible
525 				 * overflow.
526 				 */
527 				if (val != HIBITL)
528 					val = -val;
529 				else	/* number is -HIBITL; convert last */
530 					/* digit now and get positive number */
531 					*--bp = _lowdigit(&val);
532 			} else if (flagword & FPLUS) {
533 				prefix = "+";
534 				prefixlength = 1;
535 			} else if (flagword & FBLANK) {
536 				prefix = " ";
537 				prefixlength = 1;
538 			}
539 
540 		decimal:
541 			{
542 				long qval = val;
543 				long saveq;
544 
545 				if (qval <= 9) {
546 					if (qval != 0 || !(flagword & DOTSEEN))
547 						*--bp = (char)(qval + '0');
548 				} else {
549 					do {
550 						saveq = qval;
551 						qval /= 10;
552 						*--bp = (char)(saveq -
553 						    qval * 10 + '0');
554 					} while (qval > 9);
555 					*--bp = (char)(qval + '0');
556 					pdiff = (ptrdiff_t)saveq;
557 				}
558 			}
559 
560 			/* Calculate minimum padding zero requirement */
561 			if (flagword & DOTSEEN) {
562 				int leadzeroes = prec - (int)(p - bp);
563 				if (leadzeroes > 0) {
564 					otherlength = lzero = leadzeroes;
565 					flagword |= LZERO;
566 				}
567 			}
568 
569 			break;
570 
571 		case 'u':
572 			/* Fetch the argument to be printed */
573 			if (flagword & LENGTH)
574 				val = va_arg(args.ap, long);
575 			else
576 				val = va_arg(args.ap, unsigned);
577 
578 			if (flagword & SHORT)
579 				val = (unsigned short)val;
580 
581 			p = bp = buf + MAXDIGS;
582 
583 			if (val & HIBITL)
584 				*--bp = _lowdigit(&val);
585 
586 			goto decimal;
587 
588 		/*
589 		 *	non-decimal fixed point representations
590 		 *	for radix equal to a power of two
591 		 *
592 		 *	"mradix" is one less than the radix for the conversion.
593 		 *	"lradix" is one less than the base 2 log
594 		 *	of the radix for the conversion. Conversion is unsigned.
595 		 *	HIBITL is 100...000
596 		 *	binary, and is equal to	the maximum
597 		 *	negative number.
598 		 *	We assume a 2's complement machine
599 		 */
600 
601 		case 'o':
602 			mradix = 7;
603 			lradix = 2;
604 			goto fixed;
605 
606 		case 'X':
607 		case 'x':
608 		case 'p':
609 			mradix = 15;
610 			lradix = 3;
611 
612 		fixed:
613 			/* Fetch the argument to be printed */
614 			if (flagword & LENGTH)
615 				val = va_arg(args.ap, long);
616 			else
617 				val = va_arg(args.ap, unsigned);
618 
619 			if (flagword & SHORT)
620 				val = (unsigned short)val;
621 
622 			/* Set translate table for digits */
623 			tab = (fcode == 'X') ? uc_digs : lc_digs;
624 
625 			/* Entry point when printing a double which is a NaN */
626 		put_pc:
627 			/* Develop the digits of the value */
628 			p = bp = buf + MAXDIGS;
629 			{
630 				long qval = val;
631 				if (qval == 0) {
632 					if (!(flagword & DOTSEEN)) {
633 						otherlength = lzero = 1;
634 						flagword |= LZERO;
635 					}
636 				} else
637 					do {
638 						*--bp = tab[qval & mradix];
639 						qval = ((qval >> 1) & ~HIBITL)
640 						    >> lradix;
641 					} while (qval != 0);
642 			}
643 
644 			/* Calculate minimum padding zero requirement */
645 			if (flagword & DOTSEEN) {
646 				int leadzeroes = prec - (int)(p - bp);
647 				if (leadzeroes > 0) {
648 					otherlength = lzero = leadzeroes;
649 					flagword |= LZERO;
650 				}
651 			}
652 
653 			/* Handle the # flag */
654 			if (flagword & FSHARP && val != 0)
655 				switch (fcode) {
656 				case 'o':
657 					if (!(flagword & LZERO)) {
658 						otherlength = lzero = 1;
659 						flagword |= LZERO;
660 					}
661 					break;
662 				case 'x':
663 					prefix = "0x";
664 					prefixlength = 2;
665 					break;
666 				case 'X':
667 					prefix = "0X";
668 					prefixlength = 2;
669 					break;
670 				}
671 
672 			break;
673 
674 		case 'E':
675 		case 'e':
676 			/*
677 			 * E-format.  The general strategy
678 			 * here is fairly easy: we take
679 			 * what ecvt gives us and re-format it.
680 			 */
681 
682 			/* Establish default precision */
683 			if (!(flagword & DOTSEEN))
684 				prec = 6;
685 
686 			/* Fetch the value */
687 			dval = va_arg(args.ap, double);
688 
689 			/* Check for NaNs and Infinities */
690 			if (IsNANorINF(dval)) {
691 				if (IsINF(dval)) {
692 					if (IsNegNAN(dval))
693 						neg_in = 1;
694 					inf_nan = 1;
695 					bp = (fcode == 'E')? uc_inf: lc_inf;
696 					p = bp + 3;
697 					break;
698 				} else {
699 					if (IsNegNAN(dval))
700 						neg_in = 1;
701 					inf_nan = 1;
702 					val = GETNaNPC(dval);
703 					NaN_flg = SNLEN;
704 					mradix = 15;
705 					lradix = 3;
706 					if (fcode == 'E') {
707 						SNAN = uc_nan;
708 						tab =  uc_digs;
709 					} else {
710 						SNAN =  lc_nan;
711 						tab =  lc_digs;
712 					}
713 					goto put_pc;
714 				}
715 			}
716 			/* Develop the mantissa */
717 			bp = ecvt(dval, min(prec + 1, MAXECVT), &decpt, &sign);
718 
719 			/* Determine the prefix */
720 		e_merge:
721 			if (sign) {
722 				prefix = "-";
723 				prefixlength = 1;
724 			} else if (flagword & FPLUS) {
725 				prefix = "+";
726 				prefixlength = 1;
727 			} else if (flagword & FBLANK) {
728 				prefix = " ";
729 				prefixlength = 1;
730 			}
731 
732 			/* Place the first digit in the buffer */
733 			p = &buf[0];
734 			*p++ = (*bp != '\0') ? *bp++ : '0';
735 
736 			/* Put in a decimal point if needed */
737 			if (prec != 0 || (flagword & FSHARP))
738 				*p++ = _numeric[0];
739 
740 			/* Create the rest of the mantissa */
741 			{
742 				int rz = prec;
743 				for (; rz > 0 && *bp != '\0'; --rz)
744 					*p++ = *bp++;
745 				if (rz > 0) {
746 					otherlength = rzero = rz;
747 					flagword |= RZERO;
748 				}
749 			}
750 
751 			bp = &buf[0];
752 
753 			/* Create the exponent */
754 			*(suffix = &expbuf[MAXESIZ]) = '\0';
755 			if (dval != 0) {
756 				int nn = decpt - 1;
757 				if (nn < 0)
758 					nn = -nn;
759 				for (; nn > 9; nn /= 10)
760 					*--suffix = todigit(nn % 10);
761 				*--suffix = todigit(nn);
762 			}
763 
764 			/* Prepend leading zeroes to the exponent */
765 			while (suffix > &expbuf[MAXESIZ - 2])
766 				*--suffix = '0';
767 
768 			/* Put in the exponent sign */
769 			*--suffix = (decpt > 0 || dval == 0) ? '+' : '-';
770 
771 			/* Put in the e */
772 			*--suffix = isupper(fcode) ? 'E'  : 'e';
773 
774 			/* compute size of suffix */
775 			otherlength += (suffixlength =
776 			    (int)(&expbuf[MAXESIZ] - suffix));
777 			flagword |= SUFFIX;
778 
779 			break;
780 
781 		case 'f':
782 			/*
783 			 * F-format floating point.  This is a
784 			 * good deal less simple than E-format.
785 			 * The overall strategy will be to call
786 			 * fcvt, reformat its result into buf,
787 			 * and calculate how many trailing
788 			 * zeroes will be required.  There will
789 			 * never be any leading zeroes needed.
790 			 */
791 
792 			/* Establish default precision */
793 			if (!(flagword & DOTSEEN))
794 				prec = 6;
795 
796 			/* Fetch the value */
797 			dval = va_arg(args.ap, double);
798 
799 			/* Check for NaNs and Infinities  */
800 			if (IsNANorINF(dval)) {
801 				if (IsINF(dval)) {
802 					if (IsNegNAN(dval))
803 						neg_in = 1;
804 					inf_nan = 1;
805 					bp = lc_inf;
806 					p = bp + 3;
807 					break;
808 				} else {
809 					if (IsNegNAN(dval))
810 						neg_in = 1;
811 					inf_nan = 1;
812 					val  = GETNaNPC(dval);
813 					NaN_flg = SNLEN;
814 					mradix = 15;
815 					lradix = 3;
816 					tab =  lc_digs;
817 					SNAN = lc_nan;
818 					goto put_pc;
819 				}
820 			}
821 			/* Do the conversion */
822 			bp = fcvt(dval, min(prec, MAXFCVT), &decpt, &sign);
823 
824 			/* Determine the prefix */
825 		f_merge:
826 			if (sign) {
827 				prefix = "-";
828 				prefixlength = 1;
829 			} else if (flagword & FPLUS) {
830 				prefix = "+";
831 				prefixlength = 1;
832 			} else if (flagword & FBLANK) {
833 				prefix = " ";
834 				prefixlength = 1;
835 			}
836 
837 			/* Initialize buffer pointer */
838 			p = &buf[0];
839 			{
840 				int nn = decpt;
841 
842 				/* Emit the digits before the decimal point */
843 				k = 0;
844 				do {
845 					*p++ = (nn <= 0 || *bp == '\0' ||
846 					    k >= MAXFSIG) ?
847 					    '0' : (k++, *bp++);
848 				} while (--nn > 0);
849 
850 				/* Decide whether we need a decimal point */
851 				if ((flagword & FSHARP) || prec > 0)
852 					*p++ = _numeric[0];
853 
854 				/* Digits (if any) after the decimal point */
855 				nn = min(prec, MAXFCVT);
856 				if (prec > nn) {
857 					flagword |= RZERO;
858 					otherlength = rzero = prec - nn;
859 				}
860 				while (--nn >= 0)
861 					*p++ = (++decpt <= 0 || *bp == '\0' ||
862 					    k >= MAXFSIG) ?
863 					    '0' : (k++, *bp++);
864 			}
865 
866 			bp = &buf[0];
867 
868 			break;
869 
870 		case 'G':
871 		case 'g':
872 			/*
873 			 * g-format.  We play around a bit
874 			 * and then jump into e or f, as needed.
875 			 */
876 
877 			/* Establish default precision */
878 			if (!(flagword & DOTSEEN))
879 				prec = 6;
880 			else if (prec == 0)
881 				prec = 1;
882 
883 			/* Fetch the value */
884 			dval = va_arg(args.ap, double);
885 
886 			/* Check for NaN and Infinities  */
887 			if (IsNANorINF(dval)) {
888 				if (IsINF(dval)) {
889 					if (IsNegNAN(dval))
890 						neg_in = 1;
891 					bp = (fcode == 'G') ? uc_inf : lc_inf;
892 					p = bp + 3;
893 					inf_nan = 1;
894 					break;
895 				} else {
896 					if (IsNegNAN(dval))
897 						neg_in = 1;
898 					inf_nan = 1;
899 					val  = GETNaNPC(dval);
900 					NaN_flg = SNLEN;
901 					mradix = 15;
902 					lradix = 3;
903 					if (fcode == 'G') {
904 						SNAN = uc_nan;
905 						tab = uc_digs;
906 					} else {
907 						SNAN = lc_nan;
908 						tab =  lc_digs;
909 					}
910 					goto put_pc;
911 				}
912 			}
913 
914 			/* Do the conversion */
915 			bp = ecvt(dval, min(prec, MAXECVT), &decpt, &sign);
916 			if (dval == 0)
917 				decpt = 1;
918 			{
919 				int kk = prec;
920 				size_t sz;
921 
922 				if (!(flagword & FSHARP)) {
923 					sz = strlen(bp);
924 					if (sz < kk)
925 						kk = (int)sz;
926 					while (kk >= 1 && bp[kk-1] == '0')
927 						--kk;
928 				}
929 
930 				if (decpt < -3 || decpt > prec) {
931 					prec = kk - 1;
932 					goto e_merge;
933 				}
934 				prec = kk - decpt;
935 				goto f_merge;
936 			}
937 
938 		case '%':
939 			buf[0] = (char)fcode;
940 			goto c_merge;
941 
942 		case 'c':
943 			buf[0] = va_arg(args.ap, int);
944 		c_merge:
945 			p = (bp = &buf[0]) + 1;
946 			break;
947 
948 		case 's':
949 			bp = va_arg(args.ap, char *);
950 			if (!(flagword & DOTSEEN))
951 				p = bp + strlen(bp);
952 			else { /* a strnlen function would  be useful here! */
953 				char *qp = bp;
954 				while (*qp++ != '\0' && --prec >= 0)
955 					;
956 				p = qp - 1;
957 			}
958 			break;
959 
960 		case 'n':
961 			{
962 				if (flagword & LENGTH) {
963 					long *svcount;
964 					svcount = va_arg(args.ap, long *);
965 					*svcount = count;
966 				} else if (flagword & SHORT) {
967 					short *svcount;
968 					svcount = va_arg(args.ap, short *);
969 					*svcount = (short)count;
970 				} else {
971 					int *svcount;
972 					svcount = va_arg(args.ap, int *);
973 					*svcount = count;
974 				}
975 				continue;
976 			}
977 
978 		default: /* this is technically an error; what we do is to */
979 			/* back up the format pointer to the offending char */
980 			/* and continue with the format scan */
981 			format--;
982 			continue;
983 
984 		}
985 
986 		if (inf_nan) {
987 			if (neg_in) {
988 				prefix = "-";
989 				prefixlength = 1;
990 				neg_in = 0;
991 			} else if (flagword & FPLUS) {
992 				prefix = "+";
993 				prefixlength = 1;
994 			} else if (flagword & FBLANK) {
995 				prefix = " ";
996 				prefixlength = 1;
997 			}
998 			inf_nan = 0;
999 		}
1000 
1001 		/* Calculate number of padding blanks */
1002 		k = (int)(pdiff = p - bp) + prefixlength + otherlength +
1003 		    NaN_flg;
1004 		if (width <= k)
1005 			count += k;
1006 		else {
1007 			count += width;
1008 
1009 			/* Set up for padding zeroes if requested */
1010 			/* Otherwise emit padding blanks unless output is */
1011 			/* to be left-justified.  */
1012 
1013 			if (flagword & PADZERO) {
1014 				if (!(flagword & LZERO)) {
1015 					flagword |= LZERO;
1016 					lzero = width - k;
1017 				}
1018 				else
1019 					lzero += width - k;
1020 				k = width; /* cancel padding blanks */
1021 			} else
1022 				/* Blanks on left if required */
1023 				if (!(flagword & FMINUS))
1024 					PAD(_blanks, width - k);
1025 		}
1026 
1027 		/* Prefix, if any */
1028 		if (prefixlength != 0)
1029 			PUT(prefix, prefixlength);
1030 
1031 		/* If value is NaN, put string NaN */
1032 		if (NaN_flg) {
1033 			PUT(SNAN, SNLEN);
1034 			NaN_flg = 0;
1035 		}
1036 
1037 		/* Zeroes on the left */
1038 		if (flagword & LZERO)
1039 			PAD(_zeroes, lzero);
1040 
1041 		/* The value itself */
1042 		if (pdiff > 0)
1043 			PUT(bp, pdiff);
1044 
1045 		if (flagword & (RZERO | SUFFIX | FMINUS)) {
1046 			/* Zeroes on the right */
1047 			if (flagword & RZERO)
1048 				PAD(_zeroes, rzero);
1049 
1050 			/* The suffix */
1051 			if (flagword & SUFFIX)
1052 				PUT(suffix, suffixlength);
1053 
1054 			/* Blanks on the right if required */
1055 			if (flagword & FMINUS && width > k)
1056 				PAD(_blanks, width - k);
1057 		}
1058 	}
1059 }
1060 
1061 /*
1062  * This function initializes arglst, to contain the appropriate va_list values
1063  * for the first MAXARGS arguments.
1064  */
1065 void
1066 _mkarglst(char *fmt, stva_list args, stva_list arglst[])
1067 {
1068 	static char digits[] = "01234567890", skips[] = "# +-.0123456789hL$";
1069 
1070 	enum types {INT = 1, LONG, CHAR_PTR, DOUBLE, LONG_DOUBLE, VOID_PTR,
1071 		LONG_PTR, INT_PTR};
1072 	enum types typelst[MAXARGS], curtype;
1073 	int maxnum, n, curargno, flags;
1074 
1075 	/*
1076 	 * Algorithm	1. set all argument types to zero.
1077 	 *		2. walk through fmt putting arg types in typelst[].
1078 	 *		3. walk through args using va_arg(args.ap, typelst[n])
1079 	 *		   and set arglst[] to the appropriate values.
1080 	 * Assumptions:	Cannot use %*$... to specify variable position.
1081 	 */
1082 
1083 	(void) memset((void *)typelst, 0, sizeof (typelst));
1084 	maxnum = -1;
1085 	curargno = 0;
1086 	while ((fmt = strchr(fmt, '%')) != 0) {
1087 		size_t sz;
1088 
1089 		fmt++;	/* skip % */
1090 		if (fmt[sz = strspn(fmt, digits)] == '$') {
1091 			curargno = atoi(fmt) - 1;
1092 				/* convert to zero base */
1093 			if (curargno < 0)
1094 				continue;
1095 			fmt += sz + 1;
1096 		}
1097 		flags = 0;
1098 	again:;
1099 		fmt += strspn(fmt, skips);
1100 		switch (*fmt++) {
1101 		case '%':	/* there is no argument! */
1102 			continue;
1103 		case 'l':
1104 			flags |= 0x1;
1105 			goto again;
1106 		case '*':	/* int argument used for value */
1107 			/* check if there is a positional parameter */
1108 			if (isdigit(*fmt)) {
1109 				int	targno;
1110 				targno = atoi(fmt) - 1;
1111 				fmt += strspn(fmt, digits);
1112 				if (*fmt == '$')
1113 					fmt++; /* skip '$' */
1114 				if (targno >= 0 && targno < MAXARGS) {
1115 					typelst[targno] = INT;
1116 					if (maxnum < targno)
1117 						maxnum = targno;
1118 				}
1119 				goto again;
1120 			}
1121 			flags |= 0x2;
1122 			curtype = INT;
1123 			break;
1124 		case 'e':
1125 		case 'E':
1126 		case 'f':
1127 		case 'g':
1128 		case 'G':
1129 			curtype = DOUBLE;
1130 			break;
1131 		case 's':
1132 			curtype = CHAR_PTR;
1133 			break;
1134 		case 'p':
1135 			curtype = VOID_PTR;
1136 			break;
1137 		case 'n':
1138 			if (flags & 0x1)
1139 				curtype = LONG_PTR;
1140 			else
1141 				curtype = INT_PTR;
1142 			break;
1143 		default:
1144 			if (flags & 0x1)
1145 				curtype = LONG;
1146 			else
1147 				curtype = INT;
1148 			break;
1149 		}
1150 		if (curargno >= 0 && curargno < MAXARGS) {
1151 			typelst[curargno] = curtype;
1152 			if (maxnum < curargno)
1153 				maxnum = curargno;
1154 		}
1155 		curargno++;	/* default to next in list */
1156 		if (flags & 0x2)	/* took care of *, keep going */
1157 		{
1158 			flags ^= 0x2;
1159 			goto again;
1160 		}
1161 	}
1162 	for (n = 0; n <= maxnum; n++) {
1163 		arglst[n] = args;
1164 		if (typelst[n] == 0)
1165 			typelst[n] = INT;
1166 
1167 		switch (typelst[n]) {
1168 		case INT:
1169 			(void) va_arg(args.ap, int);
1170 			break;
1171 		case LONG:
1172 			(void) va_arg(args.ap, long);
1173 			break;
1174 		case CHAR_PTR:
1175 			(void) va_arg(args.ap, char *);
1176 			break;
1177 		case DOUBLE:
1178 			(void) va_arg(args.ap, double);
1179 			break;
1180 		case LONG_DOUBLE:
1181 			(void) va_arg(args.ap, double);
1182 			break;
1183 		case VOID_PTR:
1184 			(void) va_arg(args.ap, void *);
1185 			break;
1186 		case LONG_PTR:
1187 			(void) va_arg(args.ap, long *);
1188 			break;
1189 		case INT_PTR:
1190 			(void) va_arg(args.ap, int *);
1191 			break;
1192 		}
1193 	}
1194 }
1195 
1196 /*
1197  * This function is used to find the va_list value for arguments whose
1198  * position is greater than MAXARGS.  This function is slow, so hopefully
1199  * MAXARGS will be big enough so that this function need only be called in
1200  * unusual circumstances.
1201  * pargs is assumed to contain the value of arglst[MAXARGS - 1].
1202  */
1203 void
1204 _getarg(char *fmt, stva_list *pargs, int argno)
1205 {
1206 	static char digits[] = "01234567890", skips[] = "# +-.0123456789h$";
1207 	int i, curargno, flags;
1208 	size_t n;
1209 	char	*sfmt = fmt;
1210 	int	found = 1;
1211 
1212 	i = MAXARGS;
1213 	curargno = 1;
1214 	while (found) {
1215 		fmt = sfmt;
1216 		found = 0;
1217 		while ((i != argno) && (fmt = strchr(fmt, '%')) != 0) {
1218 			fmt++;	/* skip % */
1219 			if (fmt[n = strspn(fmt, digits)] == '$') {
1220 				curargno = atoi(fmt);
1221 				if (curargno <= 0)
1222 					continue;
1223 				fmt += n + 1;
1224 			}
1225 
1226 			/* find conversion specifier for next argument */
1227 			if (i != curargno) {
1228 				curargno++;
1229 				continue;
1230 			} else
1231 				found = 1;
1232 			flags = 0;
1233 		again:;
1234 			fmt += strspn(fmt, skips);
1235 			switch (*fmt++) {
1236 			case '%':	/* there is no argument! */
1237 				continue;
1238 			case 'l':
1239 				flags |= 0x1;
1240 				goto again;
1241 			case '*':	/* int argument used for value */
1242 				/*
1243 				 * check if there is a positional parameter;
1244 				 * if so, just skip it; its size will be
1245 				 * correctly determined by default
1246 				 */
1247 				if (isdigit(*fmt)) {
1248 					fmt += strspn(fmt, digits);
1249 					if (*fmt == '$')
1250 						fmt++; /* skip '$' */
1251 					goto again;
1252 				}
1253 				flags |= 0x2;
1254 				(void) va_arg((*pargs).ap, int);
1255 				break;
1256 			case 'e':
1257 			case 'E':
1258 			case 'f':
1259 			case 'g':
1260 			case 'G':
1261 				if (flags & 0x1)
1262 					(void) va_arg((*pargs).ap, double);
1263 				else
1264 					(void) va_arg((*pargs).ap, double);
1265 				break;
1266 			case 's':
1267 				(void) va_arg((*pargs).ap, char *);
1268 				break;
1269 			case 'p':
1270 				(void) va_arg((*pargs).ap, void *);
1271 				break;
1272 			case 'n':
1273 				if (flags & 0x1)
1274 					(void) va_arg((*pargs).ap, long *);
1275 				else
1276 					(void) va_arg((*pargs).ap, int *);
1277 				break;
1278 			default:
1279 				if (flags & 0x1)
1280 					(void) va_arg((*pargs).ap, long int);
1281 				else
1282 					(void) va_arg((*pargs).ap, int);
1283 				break;
1284 			}
1285 			i++;
1286 			curargno++;	/* default to next in list */
1287 			if (flags & 0x2)	/* took care of *, keep going */
1288 			{
1289 				flags ^= 0x2;
1290 				goto again;
1291 			}
1292 		}
1293 
1294 		/*
1295 		 * missing specifier for parameter, assume parameter is an int
1296 		 */
1297 		if (!found && i != argno) {
1298 			(void) va_arg((*pargs).ap, int);
1299 			i++;
1300 			curargno = i;
1301 			found = 1;
1302 		}
1303 	}
1304 }
1305