xref: /freebsd/contrib/ldns/compat/snprintf.c (revision b740c88bfb6453416926271c089262e7164dace3)
1 /* snprintf - compatibility implementation of snprintf, vsnprintf
2  *
3  * Copyright (c) 2013, NLnet Labs. All rights reserved.
4  *
5  * This software is open source.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * Redistributions of source code must retain the above copyright notice,
12  * this list of conditions and the following disclaimer.
13  *
14  * Redistributions in binary form must reproduce the above copyright notice,
15  * this list of conditions and the following disclaimer in the documentation
16  * and/or other materials provided with the distribution.
17  *
18  * Neither the name of the NLNET LABS nor the names of its contributors may
19  * be used to endorse or promote products derived from this software without
20  * specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <ldns/config.h>
36 #include <stdio.h>
37 #include <ctype.h>
38 #include <string.h>
39 #include <stdarg.h>
40 #include <stdlib.h>
41 #include <errno.h>
42 #ifdef HAVE_STDINT_H
43 #include <stdint.h>
44 #endif
45 
46 /* for test */
47 /* #define SNPRINTF_TEST 1 */
48 #ifdef SNPRINTF_TEST
49 #define snprintf my_snprintf
50 #define vsnprintf my_vsnprintf
51 #endif /* SNPRINTF_TEST */
52 
53 int snprintf(char* str, size_t size, const char* format, ...);
54 int vsnprintf(char* str, size_t size, const char* format, va_list arg);
55 
56 /**
57  * Very portable snprintf implementation, limited in functionality,
58  * esp. for %[capital] %[nonportable] and so on.  Reduced float functionality,
59  * mostly in formatting and range (e+-16), for %f and %g.
60  *
61  * %s, %d, %u, %i, %x, %c, %n and %% are fully supported.
62  *   This includes width, precision, flags 0- +, and *(arg for wid,prec).
63  * %f, %g, %m, %p have reduced support, support for wid,prec,flags,*, but
64  *   less floating point range, no %e formatting for %g.
65  */
66 int snprintf(char* str, size_t size, const char* format, ...)
67 {
68 	int r;
69 	va_list args;
70 	va_start(args, format);
71 	r = vsnprintf(str, size, format, args);
72 	va_end(args);
73 	return r;
74 }
75 
76 /** add padding to string */
77 static void
78 print_pad(char** at, size_t* left, int* ret, char p, int num)
79 {
80 	while(num--) {
81 		if(*left > 1) {
82 			*(*at)++ = p;
83 			(*left)--;
84 		}
85 		(*ret)++;
86 	}
87 }
88 
89 /** get negative symbol, 0 if none */
90 static char
91 get_negsign(int negative, int plus, int space)
92 {
93 	if(negative)
94 		return '-';
95 	if(plus)
96 		return '+';
97 	if(space)
98 		return ' ';
99 	return 0;
100 }
101 
102 #define PRINT_DEC_BUFSZ 32 /* 20 is enough for 64 bit decimals */
103 /** print decimal into buffer, returns length */
104 static int
105 print_dec(char* buf, int max, unsigned int value)
106 {
107 	int i = 0;
108 	if(value == 0) {
109 		if(max > 0) {
110 			buf[0] = '0';
111 			i = 1;
112 		}
113 	} else while(value && i < max) {
114 		buf[i++] = '0' + value % 10;
115 		value /= 10;
116 	}
117 	return i;
118 }
119 
120 /** print long decimal into buffer, returns length */
121 static int
122 print_dec_l(char* buf, int max, unsigned long value)
123 {
124 	int i = 0;
125 	if(value == 0) {
126 		if(max > 0) {
127 			buf[0] = '0';
128 			i = 1;
129 		}
130 	} else while(value && i < max) {
131 		buf[i++] = '0' + value % 10;
132 		value /= 10;
133 	}
134 	return i;
135 }
136 
137 /** print long decimal into buffer, returns length */
138 static int
139 print_dec_ll(char* buf, int max, unsigned long long value)
140 {
141 	int i = 0;
142 	if(value == 0) {
143 		if(max > 0) {
144 			buf[0] = '0';
145 			i = 1;
146 		}
147 	} else while(value && i < max) {
148 		buf[i++] = '0' + value % 10;
149 		value /= 10;
150 	}
151 	return i;
152 }
153 
154 /** print hex into buffer, returns length */
155 static int
156 print_hex(char* buf, int max, unsigned int value)
157 {
158 	const char* h = "0123456789abcdef";
159 	int i = 0;
160 	if(value == 0) {
161 		if(max > 0) {
162 			buf[0] = '0';
163 			i = 1;
164 		}
165 	} else while(value && i < max) {
166 		buf[i++] = h[value & 0x0f];
167 		value >>= 4;
168 	}
169 	return i;
170 }
171 
172 /** print long hex into buffer, returns length */
173 static int
174 print_hex_l(char* buf, int max, unsigned long value)
175 {
176 	const char* h = "0123456789abcdef";
177 	int i = 0;
178 	if(value == 0) {
179 		if(max > 0) {
180 			buf[0] = '0';
181 			i = 1;
182 		}
183 	} else while(value && i < max) {
184 		buf[i++] = h[value & 0x0f];
185 		value >>= 4;
186 	}
187 	return i;
188 }
189 
190 /** print long long hex into buffer, returns length */
191 static int
192 print_hex_ll(char* buf, int max, unsigned long long value)
193 {
194 	const char* h = "0123456789abcdef";
195 	int i = 0;
196 	if(value == 0) {
197 		if(max > 0) {
198 			buf[0] = '0';
199 			i = 1;
200 		}
201 	} else while(value && i < max) {
202 		buf[i++] = h[value & 0x0f];
203 		value >>= 4;
204 	}
205 	return i;
206 }
207 
208 /** copy string into result, reversed */
209 static void
210 spool_str_rev(char** at, size_t* left, int* ret, const char* buf, int len)
211 {
212 	int i = len;
213 	while(i) {
214 		if(*left > 1) {
215 			*(*at)++ = buf[--i];
216 			(*left)--;
217 		} else --i;
218 		(*ret)++;
219 	}
220 }
221 
222 /** copy string into result */
223 static void
224 spool_str(char** at, size_t* left, int* ret, const char* buf, int len)
225 {
226 	int i;
227 	for(i=0; i<len; i++) {
228 		if(*left > 1) {
229 			*(*at)++ = buf[i];
230 			(*left)--;
231 		}
232 		(*ret)++;
233 	}
234 }
235 
236 /** print number formatted */
237 static void
238 print_num(char** at, size_t* left, int* ret, int minw, int precision,
239 	int prgiven, int zeropad, int minus, int plus, int space,
240 	int zero, int negative, char* buf, int len)
241 {
242 	int w = len; /* excludes minus sign */
243 	char s = get_negsign(negative, plus, space);
244 	if(minus) {
245 		/* left adjust the number into the field, space padding */
246 		/* calc numw = [sign][zeroes][number] */
247 		int numw = w;
248 		if(precision == 0 && zero) numw = 0;
249 		if(numw < precision) numw = precision;
250 		if(s) numw++;
251 
252 		/* sign */
253 		if(s) print_pad(at, left, ret, s, 1);
254 
255 		/* number */
256 		if(precision == 0 && zero) {
257 			/* "" for the number */
258 		} else {
259 			if(w < precision)
260 				print_pad(at, left, ret, '0', precision - w);
261 			spool_str_rev(at, left, ret, buf, len);
262 		}
263 		/* spaces */
264 		if(numw < minw)
265 			print_pad(at, left, ret, ' ', minw - numw);
266 	} else {
267 		/* pad on the left of the number */
268 		/* calculate numw has width of [sign][zeroes][number] */
269 		int numw = w;
270 		if(precision == 0 && zero) numw = 0;
271 		if(numw < precision) numw = precision;
272 		if(!prgiven && zeropad && numw < minw) numw = minw;
273 		else if(s) numw++;
274 
275 		/* pad with spaces */
276 		if(numw < minw)
277 			print_pad(at, left, ret, ' ', minw - numw);
278 		/* print sign (and one less zeropad if so) */
279 		if(s) {
280 			print_pad(at, left, ret, s, 1);
281 			numw--;
282 		}
283 		/* pad with zeroes */
284 		if(w < numw)
285 			print_pad(at, left, ret, '0', numw - w);
286 		if(precision == 0 && zero)
287 			return;
288 		/* print the characters for the value */
289 		spool_str_rev(at, left, ret, buf, len);
290 	}
291 }
292 
293 /** print %d and %i */
294 static void
295 print_num_d(char** at, size_t* left, int* ret, int value,
296 	int minw, int precision, int prgiven, int zeropad, int minus,
297 	int plus, int space)
298 {
299 	char buf[PRINT_DEC_BUFSZ];
300 	int negative = (value < 0);
301 	int zero = (value == 0);
302 	int len = print_dec(buf, (int)sizeof(buf),
303 		(unsigned int)(negative?-value:value));
304 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
305 		plus, space, zero, negative, buf, len);
306 }
307 
308 /** print %ld and %li */
309 static void
310 print_num_ld(char** at, size_t* left, int* ret, long value,
311 	int minw, int precision, int prgiven, int zeropad, int minus,
312 	int plus, int space)
313 {
314 	char buf[PRINT_DEC_BUFSZ];
315 	int negative = (value < 0);
316 	int zero = (value == 0);
317 	int len = print_dec_l(buf, (int)sizeof(buf),
318 		(unsigned long)(negative?-value:value));
319 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
320 		plus, space, zero, negative, buf, len);
321 }
322 
323 /** print %lld and %lli */
324 static void
325 print_num_lld(char** at, size_t* left, int* ret, long long value,
326 	int minw, int precision, int prgiven, int zeropad, int minus,
327 	int plus, int space)
328 {
329 	char buf[PRINT_DEC_BUFSZ];
330 	int negative = (value < 0);
331 	int zero = (value == 0);
332 	int len = print_dec_ll(buf, (int)sizeof(buf),
333 		(unsigned long long)(negative?-value:value));
334 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
335 		plus, space, zero, negative, buf, len);
336 }
337 
338 /** print %u */
339 static void
340 print_num_u(char** at, size_t* left, int* ret, unsigned int value,
341 	int minw, int precision, int prgiven, int zeropad, int minus,
342 	int plus, int space)
343 {
344 	char buf[PRINT_DEC_BUFSZ];
345 	int negative = 0;
346 	int zero = (value == 0);
347 	int len = print_dec(buf, (int)sizeof(buf), value);
348 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
349 		plus, space, zero, negative, buf, len);
350 }
351 
352 /** print %lu */
353 static void
354 print_num_lu(char** at, size_t* left, int* ret, unsigned long value,
355 	int minw, int precision, int prgiven, int zeropad, int minus,
356 	int plus, int space)
357 {
358 	char buf[PRINT_DEC_BUFSZ];
359 	int negative = 0;
360 	int zero = (value == 0);
361 	int len = print_dec_l(buf, (int)sizeof(buf), value);
362 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
363 		plus, space, zero, negative, buf, len);
364 }
365 
366 /** print %llu */
367 static void
368 print_num_llu(char** at, size_t* left, int* ret, unsigned long long value,
369 	int minw, int precision, int prgiven, int zeropad, int minus,
370 	int plus, int space)
371 {
372 	char buf[PRINT_DEC_BUFSZ];
373 	int negative = 0;
374 	int zero = (value == 0);
375 	int len = print_dec_ll(buf, (int)sizeof(buf), value);
376 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
377 		plus, space, zero, negative, buf, len);
378 }
379 
380 /** print %x */
381 static void
382 print_num_x(char** at, size_t* left, int* ret, unsigned int value,
383 	int minw, int precision, int prgiven, int zeropad, int minus,
384 	int plus, int space)
385 {
386 	char buf[PRINT_DEC_BUFSZ];
387 	int negative = 0;
388 	int zero = (value == 0);
389 	int len = print_hex(buf, (int)sizeof(buf), value);
390 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
391 		plus, space, zero, negative, buf, len);
392 }
393 
394 /** print %lx */
395 static void
396 print_num_lx(char** at, size_t* left, int* ret, unsigned long value,
397 	int minw, int precision, int prgiven, int zeropad, int minus,
398 	int plus, int space)
399 {
400 	char buf[PRINT_DEC_BUFSZ];
401 	int negative = 0;
402 	int zero = (value == 0);
403 	int len = print_hex_l(buf, (int)sizeof(buf), value);
404 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
405 		plus, space, zero, negative, buf, len);
406 }
407 
408 /** print %llx */
409 static void
410 print_num_llx(char** at, size_t* left, int* ret, unsigned long long value,
411 	int minw, int precision, int prgiven, int zeropad, int minus,
412 	int plus, int space)
413 {
414 	char buf[PRINT_DEC_BUFSZ];
415 	int negative = 0;
416 	int zero = (value == 0);
417 	int len = print_hex_ll(buf, (int)sizeof(buf), value);
418 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
419 		plus, space, zero, negative, buf, len);
420 }
421 
422 /** print %llp */
423 static void
424 print_num_llp(char** at, size_t* left, int* ret, void* value,
425 	int minw, int precision, int prgiven, int zeropad, int minus,
426 	int plus, int space)
427 {
428 	char buf[PRINT_DEC_BUFSZ];
429 	int negative = 0;
430 	int zero = (value == 0);
431 #if defined(UINTPTR_MAX) && defined(UINT32_MAX) && (UINTPTR_MAX == UINT32_MAX)
432 	/* avoid warning about upcast on 32bit systems */
433 	unsigned long long llvalue = (unsigned long)value;
434 #else
435 	unsigned long long llvalue = (unsigned long long)value;
436 #endif
437 	int len = print_hex_ll(buf, (int)sizeof(buf), llvalue);
438 	if(zero) {
439 		buf[0]=')';
440 		buf[1]='l';
441 		buf[2]='i';
442 		buf[3]='n';
443 		buf[4]='(';
444 		len = 5;
445 	} else {
446 		/* put '0x' in front of the (reversed) buffer result */
447 		if(len < PRINT_DEC_BUFSZ)
448 			buf[len++] = 'x';
449 		if(len < PRINT_DEC_BUFSZ)
450 			buf[len++] = '0';
451 	}
452 	print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
453 		plus, space, zero, negative, buf, len);
454 }
455 
456 #define PRINT_FLOAT_BUFSZ 64 /* xx.yy with 20.20 about the max */
457 /** spool remainder after the decimal point to buffer, in reverse */
458 static int
459 print_remainder(char* buf, int max, double r, int prec)
460 {
461 	unsigned long long cap = 1;
462 	unsigned long long value;
463 	int len, i;
464 	if(prec > 19) prec = 19; /* max we can do */
465 	if(max < prec) return 0;
466 	for(i=0; i<prec; i++) {
467 		cap *= 10;
468 	}
469 	r *= (double)cap;
470 	value = (unsigned long long)r;
471 	/* see if we need to round up */
472 	if(((unsigned long long)((r - (double)value)*10.0)) >= 5) {
473 		value++;
474 		/* that might carry to numbers before the comma, if so,
475 		 * just ignore that rounding. failure because 64bitprintout */
476 		if(value >= cap)
477 			value = cap-1;
478 	}
479 	len = print_dec_ll(buf, max, value);
480 	while(len < prec) { /* pad with zeroes, e.g. if 0.0012 */
481 		buf[len++] = '0';
482 	}
483 	if(len < max)
484 		buf[len++] = '.';
485 	return len;
486 }
487 
488 /** spool floating point to buffer */
489 static int
490 print_float(char* buf, int max, double value, int prec)
491 {
492 	/* as xxx.xxx  if prec==0, no '.', with prec decimals after . */
493 	/* no conversion for NAN and INF, because we do not want to require
494 	   linking with -lm. */
495 	/* Thus, the conversions use 64bit integers to convert the numbers,
496 	 * which makes 19 digits before and after the decimal point the max */
497 	unsigned long long whole = (unsigned long long)value;
498 	double remain = value - (double)whole;
499 	int len = 0;
500 	if(prec != 0)
501 		len = print_remainder(buf, max, remain, prec);
502 	len += print_dec_ll(buf+len, max-len, whole);
503 	return len;
504 }
505 
506 /** print %f */
507 static void
508 print_num_f(char** at, size_t* left, int* ret, double value,
509 	int minw, int precision, int prgiven, int zeropad, int minus,
510 	int plus, int space)
511 {
512 	char buf[PRINT_FLOAT_BUFSZ];
513 	int negative = (value < 0);
514 	int zero = 0;
515 	int len;
516 	if(!prgiven) precision = 6;
517 	len = print_float(buf, (int)sizeof(buf), negative?-value:value,
518 		precision);
519 	print_num(at, left, ret, minw, 1, 0, zeropad, minus,
520 		plus, space, zero, negative, buf, len);
521 }
522 
523 /* rudimentary %g support */
524 static int
525 print_float_g(char* buf, int max, double value, int prec)
526 {
527 	unsigned long long whole = (unsigned long long)value;
528 	double remain = value - (double)whole;
529 	int before = 0;
530 	int len = 0;
531 
532 	/* number of digits before the decimal point */
533 	while(whole > 0) {
534 		before++;
535 		whole /= 10;
536 	}
537 	whole = (unsigned long long)value;
538 
539 	if(prec > before && remain != 0.0) {
540 		/* see if the last decimals are zero, if so, skip them */
541 		len = print_remainder(buf, max, remain, prec-before);
542 		while(len > 0 && buf[0]=='0') {
543 			memmove(buf, buf+1, --len);
544 		}
545 	}
546 	len += print_dec_ll(buf+len, max-len, whole);
547 	return len;
548 }
549 
550 
551 /** print %g */
552 static void
553 print_num_g(char** at, size_t* left, int* ret, double value,
554 	int minw, int precision, int prgiven, int zeropad, int minus,
555 	int plus, int space)
556 {
557 	char buf[PRINT_FLOAT_BUFSZ];
558 	int negative = (value < 0);
559 	int zero = 0;
560 	int len;
561 	if(!prgiven) precision = 6;
562 	if(precision == 0) precision = 1;
563 	len = print_float_g(buf, (int)sizeof(buf), negative?-value:value,
564 		precision);
565 	print_num(at, left, ret, minw, 1, 0, zeropad, minus,
566 		plus, space, zero, negative, buf, len);
567 }
568 
569 
570 /** strnlen (compat implementation) */
571 static int
572 my_strnlen(const char* s, int max)
573 {
574 	int i;
575 	for(i=0; i<max; i++)
576 		if(s[i]==0)
577 			return i;
578 	return max;
579 }
580 
581 /** print %s */
582 static void
583 print_str(char** at, size_t* left, int* ret, char* s,
584 	int minw, int precision, int prgiven, int minus)
585 {
586 	int w;
587 	/* with prec: no more than x characters from this string, stop at 0 */
588 	if(prgiven)
589 		w = my_strnlen(s, precision);
590 	else	w = (int)strlen(s); /* up to the nul */
591 	if(w < minw && !minus)
592 		print_pad(at, left, ret, ' ', minw - w);
593 	spool_str(at, left, ret, s, w);
594 	if(w < minw && minus)
595 		print_pad(at, left, ret, ' ', minw - w);
596 }
597 
598 /** print %c */
599 static void
600 print_char(char** at, size_t* left, int* ret, int c,
601 	int minw, int minus)
602 {
603 	if(1 < minw && !minus)
604 		print_pad(at, left, ret, ' ', minw - 1);
605 	print_pad(at, left, ret, c, 1);
606 	if(1 < minw && minus)
607 		print_pad(at, left, ret, ' ', minw - 1);
608 }
609 
610 
611 /**
612  * Print to string.
613  * str: string buffer for result. result will be null terminated.
614  * size: size of the buffer. null is put inside buffer.
615  * format: printf format string.
616  * arg: '...' arguments to print.
617  * returns number of characters. a null is printed after this.
618  * return number of bytes that would have been written
619  *	   if the buffer had been large enough.
620  *
621  * supported format specifiers:
622  * 	%s, %u, %d, %x, %i, %f, %g, %c, %p, %n.
623  * 	length: l, ll (for d, u, x).
624  * 	precision: 6.6d (for d, u, x)
625  * 		%f, %g precisions, 0.3f
626  * 		%20s, '.*s'
627  * 	and %%.
628  */
629 int vsnprintf(char* str, size_t size, const char* format, va_list arg)
630 {
631 	char* at = str;
632 	size_t left = size;
633 	int ret = 0;
634 	const char* fmt = format;
635 	int conv, minw, precision, prgiven, zeropad, minus, plus, space, length;
636 	while(*fmt) {
637 		/* copy string before % */
638 		while(*fmt && *fmt!='%') {
639 			if(left > 1) {
640 				*at++ = *fmt++;
641 				left--;
642 			} else fmt++;
643 			ret++;
644 		}
645 
646 		/* see if we are at end */
647 		if(!*fmt) break;
648 
649 		/* fetch next argument % designation from format string */
650 		fmt++; /* skip the '%' */
651 
652 		/********************************/
653 		/* get the argument designation */
654 		/********************************/
655 		/* we must do this vararg stuff inside this function for
656 		 * portability.  Hence, get_designation, and print_designation
657 		 * are not their own functions. */
658 
659 		/* printout designation:
660 		 * conversion specifier: x, d, u, s, c, n, m, p
661 		 * flags: # not supported
662 		 *        0 zeropad (on the left)
663 		 *	  - left adjust (right by default)
664 		 *	  ' ' printspace for positive number (in - position).
665 		 *	  + alwayssign
666 		 * fieldwidth: [1-9][0-9]* minimum field width.
667 		 * 	if this is * then type int next argument specifies the minwidth.
668 		 * 	if this is negative, the - flag is set (with positive width).
669 		 * precision: period[digits]*, %.2x.
670 		 * 	if this is * then type int next argument specifies the precision.
671 		 *	just '.' or negative value means precision=0.
672 		 *		this is mindigits to print for d, i, u, x
673 		 *		this is aftercomma digits for f
674 		 *		this is max number significant digits for g
675 		 *		maxnumber characters to be printed for s
676 		 * length: 0-none (int), 1-l (long), 2-ll (long long)
677 		 * 	notsupported: hh (char), h (short), L (long double), q, j, z, t
678 		 * Does not support %m$ and *m$ argument designation as array indices.
679 		 * Does not support %#x
680 		 *
681 		 */
682 		minw = 0;
683 		precision = 1;
684 		prgiven = 0;
685 		zeropad = 0;
686 		minus = 0;
687 		plus = 0;
688 		space = 0;
689 		length = 0;
690 
691 		/* get flags in any order */
692 		for(;;) {
693 			if(*fmt == '0')
694 				zeropad = 1;
695 			else if(*fmt == '-')
696 				minus = 1;
697 			else if(*fmt == '+')
698 				plus = 1;
699 			else if(*fmt == ' ')
700 				space = 1;
701 			else break;
702 			fmt++;
703 		}
704 
705 		/* field width */
706 		if(*fmt == '*') {
707 			fmt++; /* skip char */
708 			minw = va_arg(arg, int);
709 			if(minw < 0) {
710 				minus = 1;
711 				minw = -minw;
712 			}
713 		} else while(*fmt >= '0' && *fmt <= '9') {
714 			minw = minw*10 + (*fmt++)-'0';
715 		}
716 
717 		/* precision */
718 		if(*fmt == '.') {
719 			fmt++; /* skip period */
720 			prgiven = 1;
721 			precision = 0;
722 			if(*fmt == '*') {
723 				fmt++; /* skip char */
724 				precision = va_arg(arg, int);
725 				if(precision < 0)
726 					precision = 0;
727 			} else while(*fmt >= '0' && *fmt <= '9') {
728 				precision = precision*10 + (*fmt++)-'0';
729 			}
730 		}
731 
732 		/* length */
733 		if(*fmt == 'l') {
734 			fmt++; /* skip char */
735 			length = 1;
736 			if(*fmt == 'l') {
737 				fmt++; /* skip char */
738 				length = 2;
739 			}
740 		}
741 
742 		/* get the conversion */
743 		if(!*fmt) conv = 0;
744 		else	conv = *fmt++;
745 
746 		/***********************************/
747 		/* print that argument designation */
748 		/***********************************/
749 		switch(conv) {
750 		case 'i':
751 		case 'd':
752 			if(length == 0)
753 			    print_num_d(&at, &left, &ret, va_arg(arg, int),
754 				minw, precision, prgiven, zeropad, minus, plus, space);
755 			else if(length == 1)
756 			    print_num_ld(&at, &left, &ret, va_arg(arg, long),
757 				minw, precision, prgiven, zeropad, minus, plus, space);
758 			else if(length == 2)
759 			    print_num_lld(&at, &left, &ret,
760 				va_arg(arg, long long),
761 				minw, precision, prgiven, zeropad, minus, plus, space);
762 			break;
763 		case 'u':
764 			if(length == 0)
765 			    print_num_u(&at, &left, &ret,
766 				va_arg(arg, unsigned int),
767 				minw, precision, prgiven, zeropad, minus, plus, space);
768 			else if(length == 1)
769 			    print_num_lu(&at, &left, &ret,
770 				va_arg(arg, unsigned long),
771 				minw, precision, prgiven, zeropad, minus, plus, space);
772 			else if(length == 2)
773 			    print_num_llu(&at, &left, &ret,
774 				va_arg(arg, unsigned long long),
775 				minw, precision, prgiven, zeropad, minus, plus, space);
776 			break;
777 		case 'x':
778 			if(length == 0)
779 			    print_num_x(&at, &left, &ret,
780 				va_arg(arg, unsigned int),
781 				minw, precision, prgiven, zeropad, minus, plus, space);
782 			else if(length == 1)
783 			    print_num_lx(&at, &left, &ret,
784 				va_arg(arg, unsigned long),
785 				minw, precision, prgiven, zeropad, minus, plus, space);
786 			else if(length == 2)
787 			    print_num_llx(&at, &left, &ret,
788 				va_arg(arg, unsigned long long),
789 				minw, precision, prgiven, zeropad, minus, plus, space);
790 			break;
791 		case 's':
792 			print_str(&at, &left, &ret, va_arg(arg, char*),
793 				minw, precision, prgiven, minus);
794 			break;
795 		case 'c':
796 			print_char(&at, &left, &ret, va_arg(arg, int),
797 				minw, minus);
798 			break;
799 		case 'n':
800 			*va_arg(arg, int*) = ret;
801 			break;
802 		case 'm':
803 			print_str(&at, &left, &ret, strerror(errno),
804 				minw, precision, prgiven, minus);
805 			break;
806 		case 'p':
807 			print_num_llp(&at, &left, &ret, va_arg(arg, void*),
808 				minw, precision, prgiven, zeropad, minus, plus, space);
809 			break;
810 		case '%':
811 			print_pad(&at, &left, &ret, '%', 1);
812 			break;
813 		case 'f':
814 			print_num_f(&at, &left, &ret, va_arg(arg, double),
815 				minw, precision, prgiven, zeropad, minus, plus, space);
816 			break;
817 		case 'g':
818 			print_num_g(&at, &left, &ret, va_arg(arg, double),
819 				minw, precision, prgiven, zeropad, minus, plus, space);
820 			break;
821 		/* unknown */
822 		default:
823 		case 0: break;
824 		}
825 	}
826 
827 	/* zero terminate */
828 	if(left > 0)
829 		*at = 0;
830 	return ret;
831 }
832 
833 #ifdef SNPRINTF_TEST
834 
835 /** do tests */
836 #undef snprintf
837 #define DOTEST(bufsz, result, retval, ...) do { \
838 	char buf[bufsz]; \
839 	printf("now test %s\n", #__VA_ARGS__); \
840 	int r=my_snprintf(buf, sizeof(buf), __VA_ARGS__); \
841 	if(r != retval || strcmp(buf, result) != 0) { \
842 		printf("error test(%s) was \"%s\":%d\n", \
843 			""#bufsz", "#result", "#retval", "#__VA_ARGS__, \
844 			buf, r); \
845 		exit(1); \
846 		} \
847 	r=snprintf(buf, sizeof(buf), __VA_ARGS__); \
848 	if(r != retval || strcmp(buf, result) != 0) { \
849 		printf("error test(%s) differs with system, \"%s\":%d\n", \
850 			""#bufsz", "#result", "#retval", "#__VA_ARGS__, \
851 			buf, r); \
852 		exit(1); \
853 		} \
854 	printf("test(\"%s\":%d) passed\n", buf, r); \
855 	} while(0);
856 
857 /** test program */
858 int main(void)
859 {
860 	int x = 0;
861 
862 	/* bufsize, expectedstring, expectedretval, snprintf arguments */
863 	DOTEST(1024, "hello", 5, "hello");
864 	DOTEST(1024, "h", 1, "h");
865 	/* warning from gcc for format string, but it does work
866 	 * DOTEST(1024, "", 0, ""); */
867 
868 	DOTEST(3, "he", 5, "hello");
869 	DOTEST(1, "", 7, "%d", 7823089);
870 
871 	/* test positive numbers */
872 	DOTEST(1024, "0", 1, "%d", 0);
873 	DOTEST(1024, "1", 1, "%d", 1);
874 	DOTEST(1024, "9", 1, "%d", 9);
875 	DOTEST(1024, "15", 2, "%d", 15);
876 	DOTEST(1024, "ab15cd", 6, "ab%dcd", 15);
877 	DOTEST(1024, "167", 3, "%d", 167);
878 	DOTEST(1024, "7823089", 7, "%d", 7823089);
879 	DOTEST(1024, " 12", 3, "%3d", 12);
880 	DOTEST(1024, "012", 3, "%.3d", 12);
881 	DOTEST(1024, "012", 3, "%3.3d", 12);
882 	DOTEST(1024, "012", 3, "%03d", 12);
883 	DOTEST(1024, " 012", 4, "%4.3d", 12);
884 	DOTEST(1024, "", 0, "%.0d", 0);
885 
886 	/* test negative numbers */
887 	DOTEST(1024, "-1", 2, "%d", -1);
888 	DOTEST(1024, "-12", 3, "%3d", -12);
889 	DOTEST(1024, " -2", 3, "%3d", -2);
890 	DOTEST(1024, "-012", 4, "%.3d", -12);
891 	DOTEST(1024, "-012", 4, "%3.3d", -12);
892 	DOTEST(1024, "-012", 4, "%4.3d", -12);
893 	DOTEST(1024, " -012", 5, "%5.3d", -12);
894 	DOTEST(1024, "-12", 3, "%03d", -12);
895 	DOTEST(1024, "-02", 3, "%03d", -2);
896 	DOTEST(1024, "-15", 3, "%d", -15);
897 	DOTEST(1024, "-7307", 5, "%d", -7307);
898 	DOTEST(1024, "-12  ", 5, "%-5d", -12);
899 	DOTEST(1024, "-00012", 6, "%-.5d", -12);
900 
901 	/* test + and space flags */
902 	DOTEST(1024, "+12", 3, "%+d", 12);
903 	DOTEST(1024, " 12", 3, "% d", 12);
904 
905 	/* test %u */
906 	DOTEST(1024, "12", 2, "%u", 12);
907 	DOTEST(1024, "0", 1, "%u", 0);
908 	DOTEST(1024, "4294967295", 10, "%u", 0xffffffff);
909 
910 	/* test %x */
911 	DOTEST(1024, "0", 1, "%x", 0);
912 	DOTEST(1024, "c", 1, "%x", 12);
913 	DOTEST(1024, "12ab34cd", 8, "%x", 0x12ab34cd);
914 
915 	/* test %llu, %lld */
916 	DOTEST(1024, "18446744073709551615", 20, "%llu",
917 		(long long)0xffffffffffffffff);
918 	DOTEST(1024, "-9223372036854775808", 20, "%lld",
919 		(long long)0x8000000000000000);
920 	DOTEST(1024, "9223372036854775808", 19, "%llu",
921 		(long long)0x8000000000000000);
922 
923 	/* test %s */
924 	DOTEST(1024, "hello", 5, "%s", "hello");
925 	DOTEST(1024, "     hello", 10, "%10s", "hello");
926 	DOTEST(1024, "hello     ", 10, "%-10s", "hello");
927 	DOTEST(1024, "he", 2, "%.2s", "hello");
928 	DOTEST(1024, "  he", 4, "%4.2s", "hello");
929 	DOTEST(1024, "   h", 4, "%4.2s", "h");
930 
931 	/* test %c */
932 	DOTEST(1024, "a", 1, "%c", 'a');
933 	/* warning from gcc for format string, but it does work
934 	   DOTEST(1024, "    a", 5, "%5c", 'a');
935 	   DOTEST(1024, "a", 1, "%.0c", 'a'); */
936 
937 	/* test %n */
938 	DOTEST(1024, "hello", 5, "hello%n", &x);
939 	if(x != 5) { printf("the %%n failed\n"); exit(1); }
940 
941 	/* test %m */
942 	errno = 0;
943 	DOTEST(1024, "Success", 7, "%m");
944 
945 	/* test %p */
946 	DOTEST(1024, "0x10", 4, "%p", (void*)0x10);
947 	DOTEST(1024, "(nil)", 5, "%p", (void*)0x0);
948 
949 	/* test %% */
950 	DOTEST(1024, "%", 1, "%%");
951 
952 	/* test %f */
953 	DOTEST(1024, "0.000000", 8, "%f", 0.0);
954 	DOTEST(1024, "0.00", 4, "%.2f", 0.0);
955 	/* differs, "-0.00" DOTEST(1024, "0.00", 4, "%.2f", -0.0); */
956 	DOTEST(1024, "234.00", 6, "%.2f", 234.005);
957 	DOTEST(1024, "8973497.1246", 12, "%.4f", 8973497.12456);
958 	DOTEST(1024, "-12.000000", 10, "%f", -12.0);
959 	DOTEST(1024, "6", 1, "%.0f", 6.0);
960 
961 	DOTEST(1024, "6", 1, "%g", 6.0);
962 	DOTEST(1024, "6.1", 3, "%g", 6.1);
963 	DOTEST(1024, "6.15", 4, "%g", 6.15);
964 
965 	/* These format strings are from the code of NSD, Unbound, ldns */
966 
967 	DOTEST(1024, "abcdef", 6, "%s", "abcdef");
968 	DOTEST(1024, "005", 3, "%03u", 5);
969 	DOTEST(1024, "12345", 5, "%03u", 12345);
970 	DOTEST(1024, "5", 1, "%d", 5);
971 	DOTEST(1024, "(nil)", 5, "%p", NULL);
972 	DOTEST(1024, "12345", 5, "%ld", (long)12345);
973 	DOTEST(1024, "12345", 5, "%lu", (long)12345);
974 	DOTEST(1024, "       12345", 12, "%12u", (unsigned)12345);
975 	DOTEST(1024, "12345", 5, "%u", (unsigned)12345);
976 	DOTEST(1024, "12345", 5, "%llu", (unsigned long long)12345);
977 	DOTEST(1024, "12345", 5, "%x", 0x12345);
978 	DOTEST(1024, "12345", 5, "%llx", (long long)0x12345);
979 	DOTEST(1024, "012345", 6, "%6.6d", 12345);
980 	DOTEST(1024, "012345", 6, "%6.6u", 12345);
981 	DOTEST(1024, "1234.54", 7, "%g", 1234.54);
982 	DOTEST(1024, "123456789.54", 12, "%.12g", 123456789.54);
983 	DOTEST(1024, "3456789123456.54", 16, "%.16g", 3456789123456.54);
984 	/* %24g does not work with 24 digits, not enough accuracy,
985 	 * the first 16 digits are correct */
986 	DOTEST(1024, "12345", 5, "%3.3d", 12345);
987 	DOTEST(1024, "000", 3, "%3.3d", 0);
988 	DOTEST(1024, "001", 3, "%3.3d", 1);
989 	DOTEST(1024, "012", 3, "%3.3d", 12);
990 	DOTEST(1024, "-012", 4, "%3.3d", -12);
991 	DOTEST(1024, "he", 2, "%.2s", "hello");
992 	DOTEST(1024, "helloworld", 10, "%s%s", "hello", "world");
993 	DOTEST(1024, "he", 2, "%.*s", 2, "hello");
994 	DOTEST(1024, "  hello", 7, "%*s", 7, "hello");
995 	DOTEST(1024, "hello  ", 7, "%*s", -7, "hello");
996 	DOTEST(1024, "0", 1, "%c", '0');
997 	DOTEST(1024, "A", 1, "%c", 'A');
998 	DOTEST(1024, "", 1, "%c", 0);
999 	DOTEST(1024, "\010", 1, "%c", 8);
1000 	DOTEST(1024, "%", 1, "%%");
1001 	DOTEST(1024, "0a", 2, "%02x", 0x0a);
1002 	DOTEST(1024, "bd", 2, "%02x", 0xbd);
1003 	DOTEST(1024, "12", 2, "%02ld", (long)12);
1004 	DOTEST(1024, "02", 2, "%02ld", (long)2);
1005 	DOTEST(1024, "02", 2, "%02u", (unsigned)2);
1006 	DOTEST(1024, "765432", 6, "%05u", (unsigned)765432);
1007 	DOTEST(1024, "10.234", 6, "%0.3f", 10.23421);
1008 	DOTEST(1024, "123456.234", 10, "%0.3f", 123456.23421);
1009 	DOTEST(1024, "123456789.234", 13, "%0.3f", 123456789.23421);
1010 	DOTEST(1024, "123456.23", 9, "%.2f", 123456.23421);
1011 	DOTEST(1024, "123456", 6, "%.0f", 123456.23421);
1012 	DOTEST(1024, "0123", 4, "%.4x", 0x0123);
1013 	DOTEST(1024, "00000123", 8, "%.8x", 0x0123);
1014 	DOTEST(1024, "ffeb0cde", 8, "%.8x", 0xffeb0cde);
1015 	DOTEST(1024, " 987654321", 10, "%10lu", (unsigned long)987654321);
1016 	DOTEST(1024, "   987654321", 12, "%12lu", (unsigned long)987654321);
1017 	DOTEST(1024, "987654321", 9, "%i", 987654321);
1018 	DOTEST(1024, "-87654321", 9, "%i", -87654321);
1019 	DOTEST(1024, "hello           ", 16, "%-16s", "hello");
1020 	DOTEST(1024, "                ", 16, "%-16s", "");
1021 	DOTEST(1024, "a               ", 16, "%-16s", "a");
1022 	DOTEST(1024, "foobarfoobar    ", 16, "%-16s", "foobarfoobar");
1023 	DOTEST(1024, "foobarfoobarfoobar", 18, "%-16s", "foobarfoobarfoobar");
1024 
1025 	/* combined expressions */
1026 	DOTEST(1024, "foo 1.0 size 512 edns", 21,
1027 		"foo %s size %d %s%s", "1.0", 512, "", "edns");
1028 	DOTEST(15, "foo 1.0 size 5", 21,
1029 		"foo %s size %d %s%s", "1.0", 512, "", "edns");
1030 	DOTEST(1024, "packet 1203ceff id", 18,
1031 		"packet %2.2x%2.2x%2.2x%2.2x id", 0x12, 0x03, 0xce, 0xff);
1032 	DOTEST(1024, "/tmp/testbound_123abcd.tmp", 26, "/tmp/testbound_%u%s%s.tmp", 123, "ab", "cd");
1033 
1034 	return 0;
1035 }
1036 #endif /* SNPRINTF_TEST */
1037