1 /*
2  * Copyright Patrick Powell 1995
3  * This code is based on code written by Patrick Powell (papowell@astart.com)
4  * It may be used for any purpose as long as this notice remains intact
5  * on all source code distributions
6  */
7 
8 /**************************************************************
9  * Original:
10  * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
11  * A bombproof version of doprnt (dopr) included.
12  * Sigh.  This sort of thing is always nasty do deal with.  Note that
13  * the version here does not include floating point...
14  *
15  * snprintf() is used instead of sprintf() as it does limit checks
16  * for string length.  This covers a nasty loophole.
17  *
18  * The other functions are there to prevent NULL pointers from
19  * causing nast effects.
20  *
21  * More Recently:
22  *  Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
23  *  This was ugly.  It is still ugly.  I opted out of floating point
24  *  numbers, but the formatter understands just about everything
25  *  from the normal C string format, at least as far as I can tell from
26  *  the Solaris 2.5 printf(3S) man page.
27  *
28  *  Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
29  *    Ok, added some minimal floating point support, which means this
30  *    probably requires libm on most operating systems.  Don't yet
31  *    support the exponent (e,E) and sigfig (g,G).  Also, fmtint()
32  *    was pretty badly broken, it just wasn't being exercised in ways
33  *    which showed it, so that's been fixed.  Also, formatted the code
34  *    to mutt conventions, and removed dead code left over from the
35  *    original.  Also, there is now a builtin-test, just compile with:
36  *           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
37  *    and run snprintf for results.
38  *
39  *  Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
40  *    The PGP code was using unsigned hexadecimal formats.
41  *    Unfortunately, unsigned formats simply didn't work.
42  *
43  *  Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
44  *    The original code assumed that both snprintf() and vsnprintf() were
45  *    missing.  Some systems only have snprintf() but not vsnprintf(), so
46  *    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
47  *
48  *  Andrew Tridgell (tridge@samba.org) Oct 1998
49  *    fixed handling of %.0f
50  *    added test for HAVE_LONG_DOUBLE
51  *
52  * tridge@samba.org, idra@samba.org, April 2001
53  *    got rid of fcvt code (twas buggy and made testing harder)
54  *    added C99 semantics
55  *
56  * date: 2002/12/19 19:56:31;  author: herb;  state: Exp;  lines: +2 -0
57  * actually print args for %g and %e
58  *
59  * date: 2002/06/03 13:37:52;  author: jmcd;  state: Exp;  lines: +8 -0
60  * Since includes.h isn't included here, VA_COPY has to be defined here.  I don't
61  * see any include file that is guaranteed to be here, so I'm defining it
62  * locally.  Fixes AIX and Solaris builds.
63  *
64  * date: 2002/06/03 03:07:24;  author: tridge;  state: Exp;  lines: +5 -13
65  * put the ifdef for HAVE_VA_COPY in one place rather than in lots of
66  * functions
67  *
68  * date: 2002/05/17 14:51:22;  author: jmcd;  state: Exp;  lines: +21 -4
69  * Fix usage of va_list passed as an arg.  Use __va_copy before using it
70  * when it exists.
71  *
72  * date: 2002/04/16 22:38:04;  author: idra;  state: Exp;  lines: +20 -14
73  * Fix incorrect zpadlen handling in fmtfp.
74  * Thanks to Ollie Oldham <ollie.oldham@metro-optix.com> for spotting it.
75  * few mods to make it easier to compile the tests.
76  * added the "Ollie" test to the floating point ones.
77  *
78  * Martin Pool (mbp@samba.org) April 2003
79  *    Remove NO_CONFIG_H so that the test case can be built within a source
80  *    tree with less trouble.
81  *    Remove unnecessary SAFE_FREE() definition.
82  *
83  * Martin Pool (mbp@samba.org) May 2003
84  *    Put in a prototype for dummy_snprintf() to quiet compiler warnings.
85  *
86  *    Move #endif to make sure VA_COPY, LDOUBLE, etc are defined even
87  *    if the C library has some snprintf functions already.
88  *
89  * Damien Miller (djm@mindrot.org) Jan 2007
90  *    Fix integer overflows in return value.
91  *    Make formatting quite a bit faster by inlining dopr_outch()
92  *
93  **************************************************************/
94 
95 #include "includes.h"
96 
97 #if defined(BROKEN_SNPRINTF)		/* For those with broken snprintf() */
98 # undef HAVE_SNPRINTF
99 # undef HAVE_VSNPRINTF
100 #endif
101 
102 #if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)
103 
104 #include <ctype.h>
105 #include <stdarg.h>
106 #include <stdlib.h>
107 #include <string.h>
108 #include <limits.h>
109 #include <errno.h>
110 
111 #ifdef HAVE_LONG_DOUBLE
112 # define LDOUBLE long double
113 #else
114 # define LDOUBLE double
115 #endif
116 
117 #ifdef HAVE_LONG_LONG
118 # define LLONG long long
119 #else
120 # define LLONG long
121 #endif
122 
123 /*
124  * dopr(): poor man's version of doprintf
125  */
126 
127 /* format read states */
128 #define DP_S_DEFAULT 0
129 #define DP_S_FLAGS   1
130 #define DP_S_MIN     2
131 #define DP_S_DOT     3
132 #define DP_S_MAX     4
133 #define DP_S_MOD     5
134 #define DP_S_CONV    6
135 #define DP_S_DONE    7
136 
137 /* format flags - Bits */
138 #define DP_F_MINUS 	(1 << 0)
139 #define DP_F_PLUS  	(1 << 1)
140 #define DP_F_SPACE 	(1 << 2)
141 #define DP_F_NUM   	(1 << 3)
142 #define DP_F_ZERO  	(1 << 4)
143 #define DP_F_UP    	(1 << 5)
144 #define DP_F_UNSIGNED 	(1 << 6)
145 
146 /* Conversion Flags */
147 #define DP_C_SHORT   1
148 #define DP_C_LONG    2
149 #define DP_C_LDOUBLE 3
150 #define DP_C_LLONG   4
151 #define DP_C_SIZE    5
152 #define DP_C_INTMAX  6
153 
154 #define char_to_int(p) ((p)- '0')
155 #ifndef MAX
156 # define MAX(p,q) (((p) >= (q)) ? (p) : (q))
157 #endif
158 
159 #define DOPR_OUTCH(buf, pos, buflen, thechar) \
160 	do { \
161 		if (pos + 1 >= INT_MAX) { \
162 			errno = ERANGE; \
163 			return -1; \
164 		} \
165 		if (pos < buflen) \
166 			buf[pos] = thechar; \
167 		(pos)++; \
168 	} while (0)
169 
170 static int dopr(char *buffer, size_t maxlen, const char *format,
171     va_list args_in);
172 static int fmtstr(char *buffer, size_t *currlen, size_t maxlen,
173     char *value, int flags, int min, int max);
174 static int fmtint(char *buffer, size_t *currlen, size_t maxlen,
175     intmax_t value, int base, int min, int max, int flags);
176 static int fmtfp(char *buffer, size_t *currlen, size_t maxlen,
177     LDOUBLE fvalue, int min, int max, int flags);
178 
179 static int
180 dopr(char *buffer, size_t maxlen, const char *format, va_list args_in)
181 {
182 	char ch;
183 	intmax_t value;
184 	LDOUBLE fvalue;
185 	char *strvalue;
186 	int min;
187 	int max;
188 	int state;
189 	int flags;
190 	int cflags;
191 	size_t currlen;
192 	va_list args;
193 
194 	VA_COPY(args, args_in);
195 
196 	state = DP_S_DEFAULT;
197 	currlen = flags = cflags = min = 0;
198 	max = -1;
199 	ch = *format++;
200 
201 	while (state != DP_S_DONE) {
202 		if (ch == '\0')
203 			state = DP_S_DONE;
204 
205 		switch(state) {
206 		case DP_S_DEFAULT:
207 			if (ch == '%')
208 				state = DP_S_FLAGS;
209 			else
210 				DOPR_OUTCH(buffer, currlen, maxlen, ch);
211 			ch = *format++;
212 			break;
213 		case DP_S_FLAGS:
214 			switch (ch) {
215 			case '-':
216 				flags |= DP_F_MINUS;
217 				ch = *format++;
218 				break;
219 			case '+':
220 				flags |= DP_F_PLUS;
221 				ch = *format++;
222 				break;
223 			case ' ':
224 				flags |= DP_F_SPACE;
225 				ch = *format++;
226 				break;
227 			case '#':
228 				flags |= DP_F_NUM;
229 				ch = *format++;
230 				break;
231 			case '0':
232 				flags |= DP_F_ZERO;
233 				ch = *format++;
234 				break;
235 			default:
236 				state = DP_S_MIN;
237 				break;
238 			}
239 			break;
240 		case DP_S_MIN:
241 			if (isdigit((unsigned char)ch)) {
242 				min = 10*min + char_to_int (ch);
243 				ch = *format++;
244 			} else if (ch == '*') {
245 				min = va_arg (args, int);
246 				ch = *format++;
247 				state = DP_S_DOT;
248 			} else {
249 				state = DP_S_DOT;
250 			}
251 			break;
252 		case DP_S_DOT:
253 			if (ch == '.') {
254 				state = DP_S_MAX;
255 				ch = *format++;
256 			} else {
257 				state = DP_S_MOD;
258 			}
259 			break;
260 		case DP_S_MAX:
261 			if (isdigit((unsigned char)ch)) {
262 				if (max < 0)
263 					max = 0;
264 				max = 10*max + char_to_int (ch);
265 				ch = *format++;
266 			} else if (ch == '*') {
267 				max = va_arg (args, int);
268 				ch = *format++;
269 				state = DP_S_MOD;
270 			} else {
271 				state = DP_S_MOD;
272 			}
273 			break;
274 		case DP_S_MOD:
275 			switch (ch) {
276 			case 'h':
277 				cflags = DP_C_SHORT;
278 				ch = *format++;
279 				break;
280 			case 'j':
281 				cflags = DP_C_INTMAX;
282 				ch = *format++;
283 				break;
284 			case 'l':
285 				cflags = DP_C_LONG;
286 				ch = *format++;
287 				if (ch == 'l') {	/* It's a long long */
288 					cflags = DP_C_LLONG;
289 					ch = *format++;
290 				}
291 				break;
292 			case 'L':
293 				cflags = DP_C_LDOUBLE;
294 				ch = *format++;
295 				break;
296 			case 'z':
297 				cflags = DP_C_SIZE;
298 				ch = *format++;
299 				break;
300 			default:
301 				break;
302 			}
303 			state = DP_S_CONV;
304 			break;
305 		case DP_S_CONV:
306 			switch (ch) {
307 			case 'd':
308 			case 'i':
309 				if (cflags == DP_C_SHORT)
310 					value = va_arg (args, int);
311 				else if (cflags == DP_C_LONG)
312 					value = va_arg (args, long int);
313 				else if (cflags == DP_C_LLONG)
314 					value = va_arg (args, LLONG);
315 				else if (cflags == DP_C_SIZE)
316 					value = va_arg (args, ssize_t);
317 				else if (cflags == DP_C_INTMAX)
318 					value = va_arg (args, intmax_t);
319 				else
320 					value = va_arg (args, int);
321 				if (fmtint(buffer, &currlen, maxlen,
322 				    value, 10, min, max, flags) == -1)
323 					return -1;
324 				break;
325 			case 'o':
326 				flags |= DP_F_UNSIGNED;
327 				if (cflags == DP_C_SHORT)
328 					value = va_arg (args, unsigned int);
329 				else if (cflags == DP_C_LONG)
330 					value = (long)va_arg (args, unsigned long int);
331 				else if (cflags == DP_C_LLONG)
332 					value = (long)va_arg (args, unsigned LLONG);
333 				else if (cflags == DP_C_SIZE)
334 					value = va_arg (args, size_t);
335 #ifdef notyet
336 				else if (cflags == DP_C_INTMAX)
337 					value = va_arg (args, uintmax_t);
338 #endif
339 				else
340 					value = (long)va_arg (args, unsigned int);
341 				if (fmtint(buffer, &currlen, maxlen, value,
342 				    8, min, max, flags) == -1)
343 					return -1;
344 				break;
345 			case 'u':
346 				flags |= DP_F_UNSIGNED;
347 				if (cflags == DP_C_SHORT)
348 					value = va_arg (args, unsigned int);
349 				else if (cflags == DP_C_LONG)
350 					value = (long)va_arg (args, unsigned long int);
351 				else if (cflags == DP_C_LLONG)
352 					value = (LLONG)va_arg (args, unsigned LLONG);
353 				else if (cflags == DP_C_SIZE)
354 					value = va_arg (args, size_t);
355 #ifdef notyet
356 				else if (cflags == DP_C_INTMAX)
357 					value = va_arg (args, uintmax_t);
358 #endif
359 				else
360 					value = (long)va_arg (args, unsigned int);
361 				if (fmtint(buffer, &currlen, maxlen, value,
362 				    10, min, max, flags) == -1)
363 					return -1;
364 				break;
365 			case 'X':
366 				flags |= DP_F_UP;
367 			case 'x':
368 				flags |= DP_F_UNSIGNED;
369 				if (cflags == DP_C_SHORT)
370 					value = va_arg (args, unsigned int);
371 				else if (cflags == DP_C_LONG)
372 					value = (long)va_arg (args, unsigned long int);
373 				else if (cflags == DP_C_LLONG)
374 					value = (LLONG)va_arg (args, unsigned LLONG);
375 				else if (cflags == DP_C_SIZE)
376 					value = va_arg (args, size_t);
377 #ifdef notyet
378 				else if (cflags == DP_C_INTMAX)
379 					value = va_arg (args, uintmax_t);
380 #endif
381 				else
382 					value = (long)va_arg (args, unsigned int);
383 				if (fmtint(buffer, &currlen, maxlen, value,
384 				    16, min, max, flags) == -1)
385 					return -1;
386 				break;
387 			case 'f':
388 				if (cflags == DP_C_LDOUBLE)
389 					fvalue = va_arg (args, LDOUBLE);
390 				else
391 					fvalue = va_arg (args, double);
392 				if (fmtfp(buffer, &currlen, maxlen, fvalue,
393 				    min, max, flags) == -1)
394 					return -1;
395 				break;
396 			case 'E':
397 				flags |= DP_F_UP;
398 			case 'e':
399 				if (cflags == DP_C_LDOUBLE)
400 					fvalue = va_arg (args, LDOUBLE);
401 				else
402 					fvalue = va_arg (args, double);
403 				if (fmtfp(buffer, &currlen, maxlen, fvalue,
404 				    min, max, flags) == -1)
405 					return -1;
406 				break;
407 			case 'G':
408 				flags |= DP_F_UP;
409 			case 'g':
410 				if (cflags == DP_C_LDOUBLE)
411 					fvalue = va_arg (args, LDOUBLE);
412 				else
413 					fvalue = va_arg (args, double);
414 				if (fmtfp(buffer, &currlen, maxlen, fvalue,
415 				    min, max, flags) == -1)
416 					return -1;
417 				break;
418 			case 'c':
419 				DOPR_OUTCH(buffer, currlen, maxlen,
420 				    va_arg (args, int));
421 				break;
422 			case 's':
423 				strvalue = va_arg (args, char *);
424 				if (!strvalue) strvalue = "(NULL)";
425 				if (max == -1) {
426 					max = strlen(strvalue);
427 				}
428 				if (min > 0 && max >= 0 && min > max) max = min;
429 				if (fmtstr(buffer, &currlen, maxlen,
430 				    strvalue, flags, min, max) == -1)
431 					return -1;
432 				break;
433 			case 'p':
434 				strvalue = va_arg (args, void *);
435 				if (fmtint(buffer, &currlen, maxlen,
436 				    (long) strvalue, 16, min, max, flags) == -1)
437 					return -1;
438 				break;
439 #if we_dont_want_this_in_openssh
440 			case 'n':
441 				if (cflags == DP_C_SHORT) {
442 					short int *num;
443 					num = va_arg (args, short int *);
444 					*num = currlen;
445 				} else if (cflags == DP_C_LONG) {
446 					long int *num;
447 					num = va_arg (args, long int *);
448 					*num = (long int)currlen;
449 				} else if (cflags == DP_C_LLONG) {
450 					LLONG *num;
451 					num = va_arg (args, LLONG *);
452 					*num = (LLONG)currlen;
453 				} else if (cflags == DP_C_SIZE) {
454 					ssize_t *num;
455 					num = va_arg (args, ssize_t *);
456 					*num = (ssize_t)currlen;
457 				} else if (cflags == DP_C_INTMAX) {
458 					intmax_t *num;
459 					num = va_arg (args, intmax_t *);
460 					*num = (intmax_t)currlen;
461 				} else {
462 					int *num;
463 					num = va_arg (args, int *);
464 					*num = currlen;
465 				}
466 				break;
467 #endif
468 			case '%':
469 				DOPR_OUTCH(buffer, currlen, maxlen, ch);
470 				break;
471 			case 'w':
472 				/* not supported yet, treat as next char */
473 				ch = *format++;
474 				break;
475 			default:
476 				/* Unknown, skip */
477 				break;
478 			}
479 			ch = *format++;
480 			state = DP_S_DEFAULT;
481 			flags = cflags = min = 0;
482 			max = -1;
483 			break;
484 		case DP_S_DONE:
485 			break;
486 		default:
487 			/* hmm? */
488 			break; /* some picky compilers need this */
489 		}
490 	}
491 	if (maxlen != 0) {
492 		if (currlen < maxlen - 1)
493 			buffer[currlen] = '\0';
494 		else if (maxlen > 0)
495 			buffer[maxlen - 1] = '\0';
496 	}
497 
498 	return currlen < INT_MAX ? (int)currlen : -1;
499 }
500 
501 static int
502 fmtstr(char *buffer, size_t *currlen, size_t maxlen,
503     char *value, int flags, int min, int max)
504 {
505 	int padlen, strln;     /* amount to pad */
506 	int cnt = 0;
507 
508 #ifdef DEBUG_SNPRINTF
509 	printf("fmtstr min=%d max=%d s=[%s]\n", min, max, value);
510 #endif
511 	if (value == 0) {
512 		value = "<NULL>";
513 	}
514 
515 	for (strln = 0; strln < max && value[strln]; ++strln); /* strlen */
516 	padlen = min - strln;
517 	if (padlen < 0)
518 		padlen = 0;
519 	if (flags & DP_F_MINUS)
520 		padlen = -padlen; /* Left Justify */
521 
522 	while ((padlen > 0) && (cnt < max)) {
523 		DOPR_OUTCH(buffer, *currlen, maxlen, ' ');
524 		--padlen;
525 		++cnt;
526 	}
527 	while (*value && (cnt < max)) {
528 		DOPR_OUTCH(buffer, *currlen, maxlen, *value);
529 		value++;
530 		++cnt;
531 	}
532 	while ((padlen < 0) && (cnt < max)) {
533 		DOPR_OUTCH(buffer, *currlen, maxlen, ' ');
534 		++padlen;
535 		++cnt;
536 	}
537 	return 0;
538 }
539 
540 /* Have to handle DP_F_NUM (ie 0x and 0 alternates) */
541 
542 static int
543 fmtint(char *buffer, size_t *currlen, size_t maxlen,
544     intmax_t value, int base, int min, int max, int flags)
545 {
546 	int signvalue = 0;
547 	unsigned LLONG uvalue;
548 	char convert[20];
549 	int place = 0;
550 	int spadlen = 0; /* amount to space pad */
551 	int zpadlen = 0; /* amount to zero pad */
552 	int caps = 0;
553 
554 	if (max < 0)
555 		max = 0;
556 
557 	uvalue = value;
558 
559 	if(!(flags & DP_F_UNSIGNED)) {
560 		if( value < 0 ) {
561 			signvalue = '-';
562 			uvalue = -value;
563 		} else {
564 			if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
565 				signvalue = '+';
566 			else if (flags & DP_F_SPACE)
567 				signvalue = ' ';
568 		}
569 	}
570 
571 	if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */
572 
573 	do {
574 		convert[place++] =
575 			(caps? "0123456789ABCDEF":"0123456789abcdef")
576 			[uvalue % (unsigned)base  ];
577 		uvalue = (uvalue / (unsigned)base );
578 	} while(uvalue && (place < 20));
579 	if (place == 20) place--;
580 	convert[place] = 0;
581 
582 	zpadlen = max - place;
583 	spadlen = min - MAX (max, place) - (signvalue ? 1 : 0);
584 	if (zpadlen < 0) zpadlen = 0;
585 	if (spadlen < 0) spadlen = 0;
586 	if (flags & DP_F_ZERO) {
587 		zpadlen = MAX(zpadlen, spadlen);
588 		spadlen = 0;
589 	}
590 	if (flags & DP_F_MINUS)
591 		spadlen = -spadlen; /* Left Justifty */
592 
593 #ifdef DEBUG_SNPRINTF
594 	printf("zpad: %d, spad: %d, min: %d, max: %d, place: %d\n",
595 	       zpadlen, spadlen, min, max, place);
596 #endif
597 
598 	/* Spaces */
599 	while (spadlen > 0) {
600 		DOPR_OUTCH(buffer, *currlen, maxlen, ' ');
601 		--spadlen;
602 	}
603 
604 	/* Sign */
605 	if (signvalue)
606 		DOPR_OUTCH(buffer, *currlen, maxlen, signvalue);
607 
608 	/* Zeros */
609 	if (zpadlen > 0) {
610 		while (zpadlen > 0) {
611 			DOPR_OUTCH(buffer, *currlen, maxlen, '0');
612 			--zpadlen;
613 		}
614 	}
615 
616 	/* Digits */
617 	while (place > 0) {
618 		--place;
619 		DOPR_OUTCH(buffer, *currlen, maxlen, convert[place]);
620 	}
621 
622 	/* Left Justified spaces */
623 	while (spadlen < 0) {
624 		DOPR_OUTCH(buffer, *currlen, maxlen, ' ');
625 		++spadlen;
626 	}
627 	return 0;
628 }
629 
630 static LDOUBLE abs_val(LDOUBLE value)
631 {
632 	LDOUBLE result = value;
633 
634 	if (value < 0)
635 		result = -value;
636 
637 	return result;
638 }
639 
640 static LDOUBLE POW10(int val)
641 {
642 	LDOUBLE result = 1;
643 
644 	while (val) {
645 		result *= 10;
646 		val--;
647 	}
648 
649 	return result;
650 }
651 
652 static LLONG ROUND(LDOUBLE value)
653 {
654 	LLONG intpart;
655 
656 	intpart = (LLONG)value;
657 	value = value - intpart;
658 	if (value >= 0.5) intpart++;
659 
660 	return intpart;
661 }
662 
663 /* a replacement for modf that doesn't need the math library. Should
664    be portable, but slow */
665 static double my_modf(double x0, double *iptr)
666 {
667 	int i;
668 	long l;
669 	double x = x0;
670 	double f = 1.0;
671 
672 	for (i=0;i<100;i++) {
673 		l = (long)x;
674 		if (l <= (x+1) && l >= (x-1)) break;
675 		x *= 0.1;
676 		f *= 10.0;
677 	}
678 
679 	if (i == 100) {
680 		/*
681 		 * yikes! the number is beyond what we can handle.
682 		 * What do we do?
683 		 */
684 		(*iptr) = 0;
685 		return 0;
686 	}
687 
688 	if (i != 0) {
689 		double i2;
690 		double ret;
691 
692 		ret = my_modf(x0-l*f, &i2);
693 		(*iptr) = l*f + i2;
694 		return ret;
695 	}
696 
697 	(*iptr) = l;
698 	return x - (*iptr);
699 }
700 
701 
702 static int
703 fmtfp (char *buffer, size_t *currlen, size_t maxlen,
704     LDOUBLE fvalue, int min, int max, int flags)
705 {
706 	int signvalue = 0;
707 	double ufvalue;
708 	char iconvert[311];
709 	char fconvert[311];
710 	int iplace = 0;
711 	int fplace = 0;
712 	int padlen = 0; /* amount to pad */
713 	int zpadlen = 0;
714 	int caps = 0;
715 	int idx;
716 	double intpart;
717 	double fracpart;
718 	double temp;
719 
720 	/*
721 	 * AIX manpage says the default is 0, but Solaris says the default
722 	 * is 6, and sprintf on AIX defaults to 6
723 	 */
724 	if (max < 0)
725 		max = 6;
726 
727 	ufvalue = abs_val (fvalue);
728 
729 	if (fvalue < 0) {
730 		signvalue = '-';
731 	} else {
732 		if (flags & DP_F_PLUS) { /* Do a sign (+/i) */
733 			signvalue = '+';
734 		} else {
735 			if (flags & DP_F_SPACE)
736 				signvalue = ' ';
737 		}
738 	}
739 
740 #if 0
741 	if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */
742 #endif
743 
744 #if 0
745 	 if (max == 0) ufvalue += 0.5; /* if max = 0 we must round */
746 #endif
747 
748 	/*
749 	 * Sorry, we only support 16 digits past the decimal because of our
750 	 * conversion method
751 	 */
752 	if (max > 16)
753 		max = 16;
754 
755 	/* We "cheat" by converting the fractional part to integer by
756 	 * multiplying by a factor of 10
757 	 */
758 
759 	temp = ufvalue;
760 	my_modf(temp, &intpart);
761 
762 	fracpart = ROUND((POW10(max)) * (ufvalue - intpart));
763 
764 	if (fracpart >= POW10(max)) {
765 		intpart++;
766 		fracpart -= POW10(max);
767 	}
768 
769 	/* Convert integer part */
770 	do {
771 		temp = intpart*0.1;
772 		my_modf(temp, &intpart);
773 		idx = (int) ((temp -intpart +0.05)* 10.0);
774 		/* idx = (int) (((double)(temp*0.1) -intpart +0.05) *10.0); */
775 		/* printf ("%llf, %f, %x\n", temp, intpart, idx); */
776 		iconvert[iplace++] =
777 			(caps? "0123456789ABCDEF":"0123456789abcdef")[idx];
778 	} while (intpart && (iplace < 311));
779 	if (iplace == 311) iplace--;
780 	iconvert[iplace] = 0;
781 
782 	/* Convert fractional part */
783 	if (fracpart)
784 	{
785 		do {
786 			temp = fracpart*0.1;
787 			my_modf(temp, &fracpart);
788 			idx = (int) ((temp -fracpart +0.05)* 10.0);
789 			/* idx = (int) ((((temp/10) -fracpart) +0.05) *10); */
790 			/* printf ("%lf, %lf, %ld\n", temp, fracpart, idx ); */
791 			fconvert[fplace++] =
792 			(caps? "0123456789ABCDEF":"0123456789abcdef")[idx];
793 		} while(fracpart && (fplace < 311));
794 		if (fplace == 311) fplace--;
795 	}
796 	fconvert[fplace] = 0;
797 
798 	/* -1 for decimal point, another -1 if we are printing a sign */
799 	padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0);
800 	zpadlen = max - fplace;
801 	if (zpadlen < 0) zpadlen = 0;
802 	if (padlen < 0)
803 		padlen = 0;
804 	if (flags & DP_F_MINUS)
805 		padlen = -padlen; /* Left Justifty */
806 
807 	if ((flags & DP_F_ZERO) && (padlen > 0)) {
808 		if (signvalue) {
809 			DOPR_OUTCH(buffer, *currlen, maxlen, signvalue);
810 			--padlen;
811 			signvalue = 0;
812 		}
813 		while (padlen > 0) {
814 			DOPR_OUTCH(buffer, *currlen, maxlen, '0');
815 			--padlen;
816 		}
817 	}
818 	while (padlen > 0) {
819 		DOPR_OUTCH(buffer, *currlen, maxlen, ' ');
820 		--padlen;
821 	}
822 	if (signvalue)
823 		DOPR_OUTCH(buffer, *currlen, maxlen, signvalue);
824 
825 	while (iplace > 0) {
826 		--iplace;
827 		DOPR_OUTCH(buffer, *currlen, maxlen, iconvert[iplace]);
828 	}
829 
830 #ifdef DEBUG_SNPRINTF
831 	printf("fmtfp: fplace=%d zpadlen=%d\n", fplace, zpadlen);
832 #endif
833 
834 	/*
835 	 * Decimal point.  This should probably use locale to find the correct
836 	 * char to print out.
837 	 */
838 	if (max > 0) {
839 		DOPR_OUTCH(buffer, *currlen, maxlen, '.');
840 
841 		while (zpadlen > 0) {
842 			DOPR_OUTCH(buffer, *currlen, maxlen, '0');
843 			--zpadlen;
844 		}
845 
846 		while (fplace > 0) {
847 			--fplace;
848 			DOPR_OUTCH(buffer, *currlen, maxlen, fconvert[fplace]);
849 		}
850 	}
851 
852 	while (padlen < 0) {
853 		DOPR_OUTCH(buffer, *currlen, maxlen, ' ');
854 		++padlen;
855 	}
856 	return 0;
857 }
858 #endif /* !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF) */
859 
860 #if !defined(HAVE_VSNPRINTF)
861 int
862 vsnprintf (char *str, size_t count, const char *fmt, va_list args)
863 {
864 	return dopr(str, count, fmt, args);
865 }
866 #endif
867 
868 #if !defined(HAVE_SNPRINTF)
869 int
870 snprintf(char *str, size_t count, SNPRINTF_CONST char *fmt, ...)
871 {
872 	size_t ret;
873 	va_list ap;
874 
875 	va_start(ap, fmt);
876 	ret = vsnprintf(str, count, fmt, ap);
877 	va_end(ap);
878 	return ret;
879 }
880 #endif
881