printf.c
Go to the documentation of this file.
1 ///////////////////////////////////////////////////////////////////////////////
2 // \author (c) Marco Paland (info@paland.com)
3 // 2014-2019, PALANDesign Hannover, Germany
4 //
5 // \license The MIT License (MIT)
6 //
7 // Permission is hereby granted, free of charge, to any person obtaining a copy
8 // of this software and associated documentation files (the "Software"), to deal
9 // in the Software without restriction, including without limitation the rights
10 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 // copies of the Software, and to permit persons to whom the Software is
12 // furnished to do so, subject to the following conditions:
13 //
14 // The above copyright notice and this permission notice shall be included in
15 // all copies or substantial portions of the Software.
16 //
17 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 // THE SOFTWARE.
24 //
25 // \brief Tiny printf, sprintf and (v)snprintf implementation, optimized for speed on
26 // embedded systems with a very limited resources. These routines are thread
27 // safe and reentrant!
28 // Use this instead of the bloated standard/newlib printf cause these use
29 // malloc for printf (and may not be thread safe).
30 //
31 ///////////////////////////////////////////////////////////////////////////////
32
33 #include <stdbool.h>
34 #include <stdint.h>
35
36 #include "printf.h"
37
38
39 // define this globally (e.g. gcc -DPRINTF_INCLUDE_CONFIG_H ...) to include the
40 // printf_config.h header file
41 // default: undefined
42 #ifdef PRINTF_INCLUDE_CONFIG_H
43 #include "printf_config.h"
44 #endif
45
46
47 // 'ntoa' conversion buffer size, this must be big enough to hold one converted
48 // numeric number including padded zeros (dynamically created on stack)
49 // default: 32 byte
50 #ifndef PRINTF_NTOA_BUFFER_SIZE
51 #define PRINTF_NTOA_BUFFER_SIZE 32U
52 #endif
53
54 // 'ftoa' conversion buffer size, this must be big enough to hold one converted
55 // float number including padded zeros (dynamically created on stack)
56 // default: 32 byte
57 #ifndef PRINTF_FTOA_BUFFER_SIZE
58 #define PRINTF_FTOA_BUFFER_SIZE 32U
59 #endif
60
61 // support for the floating point type (%f)
62 // default: activated
63 #ifndef PRINTF_DISABLE_SUPPORT_FLOAT
64 #define PRINTF_SUPPORT_FLOAT
65 #endif
66
67 // support for exponential floating point notation (%e/%g)
68 // default: activated
69 #ifndef PRINTF_DISABLE_SUPPORT_EXPONENTIAL
70 #define PRINTF_SUPPORT_EXPONENTIAL
71 #endif
72
73 // define the default floating point precision
74 // default: 6 digits
75 #ifndef PRINTF_DEFAULT_FLOAT_PRECISION
76 #define PRINTF_DEFAULT_FLOAT_PRECISION 6U
77 #endif
78
79 // define the largest float suitable to print with %f
80 // default: 1e9
81 #ifndef PRINTF_MAX_FLOAT
82 #define PRINTF_MAX_FLOAT 1e9
83 #endif
84
85 // support for the long long types (%llu or %p)
86 // default: activated
87 #ifndef PRINTF_DISABLE_SUPPORT_LONG_LONG
88 #define PRINTF_SUPPORT_LONG_LONG
89 #endif
90
91 // support for the ptrdiff_t type (%t)
92 // ptrdiff_t is normally defined in <stddef.h> as long or long long type
93 // default: activated
94 #ifndef PRINTF_DISABLE_SUPPORT_PTRDIFF_T
95 #define PRINTF_SUPPORT_PTRDIFF_T
96 #endif
97
98 ///////////////////////////////////////////////////////////////////////////////
99
100 // internal flag definitions
101 #define FLAGS_ZEROPAD (1U << 0U)
102 #define FLAGS_LEFT (1U << 1U)
103 #define FLAGS_PLUS (1U << 2U)
104 #define FLAGS_SPACE (1U << 3U)
105 #define FLAGS_HASH (1U << 4U)
106 #define FLAGS_UPPERCASE (1U << 5U)
107 #define FLAGS_CHAR (1U << 6U)
108 #define FLAGS_SHORT (1U << 7U)
109 #define FLAGS_LONG (1U << 8U)
110 #define FLAGS_LONG_LONG (1U << 9U)
111 #define FLAGS_PRECISION (1U << 10U)
112 #define FLAGS_ADAPT_EXP (1U << 11U)
113
114
115 // import float.h for DBL_MAX
116 #if defined(PRINTF_SUPPORT_FLOAT)
117 #include <float.h>
118 #endif
119
120 // output function type
121 typedef void (*out_fct_type)(char character, void* buffer, size_t idx, size_t maxlen);
122
123
124 // wrapper (used as buffer) for output function type
125 typedef struct {
126 void (*fct)(char character, void* arg);
127 void* arg;
128 } out_fct_wrap_type;
129
130
131 // internal buffer output
132 static inline void _out_buffer(char character, void* buffer, size_t idx, size_t maxlen)
133 {
134 if (idx < maxlen) {
135 ((char*)buffer)[idx] = character;
136 }
137 }
138
139
140 // internal null output
141 static inline void _out_null(char character, void* buffer, size_t idx, size_t maxlen)
142 {
143 (void)character; (void)buffer; (void)idx; (void)maxlen;
144 }
145
146
147 // internal _putchar wrapper
148 static inline void _out_char(char character, void* buffer, size_t idx, size_t maxlen)
149 {
150 (void)buffer; (void)idx; (void)maxlen;
151 if (character) {
152 _putchar(character);
153 }
154 }
155
156
157 // internal output function wrapper
158 static inline void _out_fct(char character, void* buffer, size_t idx, size_t maxlen)
159 {
160 (void)idx; (void)maxlen;
161 if (character) {
162 // buffer is the output fct pointer
163 ((out_fct_wrap_type*)buffer)->fct(character, ((out_fct_wrap_type*)buffer)->arg);
164 }
165 }
166
167
168 // internal secure strlen
169 // \return The length of the string (excluding the terminating 0) limited by 'maxsize'
170 static inline unsigned int _strnlen_s(const char* str, size_t maxsize)
171 {
172 const char* s;
173 for (s = str; *s && maxsize--; ++s);
174 return (unsigned int)(s - str);
175 }
176
177
178 // internal test if char is a digit (0-9)
179 // \return true if char is a digit
180 static inline bool _is_digit(char ch)
181 {
182 return (ch >= '0') && (ch <= '9');
183 }
184
185
186 // internal ASCII string to unsigned int conversion
187 static unsigned int _atoi(const char** str)
188 {
189 unsigned int i = 0U;
190 while (_is_digit(**str)) {
191 i = i * 10U + (unsigned int)(*((*str)++) - '0');
192 }
193 return i;
194 }
195
196
197 // output the specified string in reverse, taking care of any zero-padding
198 static size_t _out_rev(out_fct_type out, char* buffer, size_t idx, size_t maxlen, const char* buf, size_t len, unsigned int width, unsigned int flags)
199 {
200 const size_t start_idx = idx;
201
202 // pad spaces up to given width
203 if (!(flags & FLAGS_LEFT) && !(flags & FLAGS_ZEROPAD)) {
204 for (size_t i = len; i < width; i++) {
205 out(' ', buffer, idx++, maxlen);
206 }
207 }
208
209 // reverse string
210 while (len) {
211 out(buf[--len], buffer, idx++, maxlen);
212 }
213
214 // append pad spaces up to given width
215 if (flags & FLAGS_LEFT) {
216 while (idx - start_idx < width) {
217 out(' ', buffer, idx++, maxlen);
218 }
219 }
220
221 return idx;
222 }
223
224
225 // internal itoa format
226 static size_t _ntoa_format(out_fct_type out, char* buffer, size_t idx, size_t maxlen, char* buf, size_t len, bool negative, unsigned int base, unsigned int prec, unsigned int width, unsigned int flags)
227 {
228 // pad leading zeros
229 if (!(flags & FLAGS_LEFT)) {
230 if (width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
231 width--;
232 }
233 while ((len < prec) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
234 buf[len++] = '0';
235 }
236 while ((flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
237 buf[len++] = '0';
238 }
239 }
240
241 // handle hash
242 if (flags & FLAGS_HASH) {
243 if (!(flags & FLAGS_PRECISION) && len && ((len == prec) || (len == width))) {
244 len--;
245 if (len && (base == 16U)) {
246 len--;
247 }
248 }
249 if ((base == 16U) && !(flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
250 buf[len++] = 'x';
251 }
252 else if ((base == 16U) && (flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
253 buf[len++] = 'X';
254 }
255 else if ((base == 2U) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
256 buf[len++] = 'b';
257 }
258 if (len < PRINTF_NTOA_BUFFER_SIZE) {
259 buf[len++] = '0';
260 }
261 }
262
263 if (len < PRINTF_NTOA_BUFFER_SIZE) {
264 if (negative) {
265 buf[len++] = '-';
266 }
267 else if (flags & FLAGS_PLUS) {
268 buf[len++] = '+'; // ignore the space if the '+' exists
269 }
270 else if (flags & FLAGS_SPACE) {
271 buf[len++] = ' ';
272 }
273 }
274
275 return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
276 }
277
278
279 // internal itoa for 'long' type
280 static size_t _ntoa_long(out_fct_type out, char* buffer, size_t idx, size_t maxlen, unsigned long value, bool negative, unsigned long base, unsigned int prec, unsigned int width, unsigned int flags)
281 {
282 char buf[PRINTF_NTOA_BUFFER_SIZE];
283 size_t len = 0U;
284
285 // no hash for 0 values
286 if (!value) {
287 flags &= ~FLAGS_HASH;
288 }
289
290 // write if precision != 0 and value is != 0
291 if (!(flags & FLAGS_PRECISION) || value) {
292 do {
293 const char digit = (char)(value % base);
294 buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10;
295 value /= base;
296 } while (value && (len < PRINTF_NTOA_BUFFER_SIZE));
297 }
298
299 return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags);
300 }
301
302
303 // internal itoa for 'long long' type
304 #if defined(PRINTF_SUPPORT_LONG_LONG)
305 static size_t _ntoa_long_long(out_fct_type out, char* buffer, size_t idx, size_t maxlen, unsigned long long value, bool negative, unsigned long long base, unsigned int prec, unsigned int width, unsigned int flags)
306 {
307 char buf[PRINTF_NTOA_BUFFER_SIZE];
308 size_t len = 0U;
309
310 // no hash for 0 values
311 if (!value) {
312 flags &= ~FLAGS_HASH;
313 }
314
315 // write if precision != 0 and value is != 0
316 if (!(flags & FLAGS_PRECISION) || value) {
317 do {
318 const char digit = (char)(value % base);
319 buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10;
320 value /= base;
321 } while (value && (len < PRINTF_NTOA_BUFFER_SIZE));
322 }
323
324 return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags);
325 }
326 #endif // PRINTF_SUPPORT_LONG_LONG
327
328
329 #if defined(PRINTF_SUPPORT_FLOAT)
330
331 #if defined(PRINTF_SUPPORT_EXPONENTIAL)
332 // forward declaration so that _ftoa can switch to exp notation for values > PRINTF_MAX_FLOAT
333 static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags);
334 #endif
335
336
337 // internal ftoa for fixed decimal floating point
338 static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)
339 {
340 char buf[PRINTF_FTOA_BUFFER_SIZE];
341 size_t len = 0U;
342 double diff = 0.0;
343
344 // powers of 10
345 static const double pow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 };
346
347 // test for special values
348 if (value != value)
349 return _out_rev(out, buffer, idx, maxlen, "nan", 3, width, flags);
350 if (value < -DBL_MAX)
351 return _out_rev(out, buffer, idx, maxlen, "fni-", 4, width, flags);
352 if (value > DBL_MAX)
353 return _out_rev(out, buffer, idx, maxlen, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4U : 3U, width, flags);
354
355 // test for very large values
356 // standard printf behavior is to print EVERY whole number digit -- which could be 100s of characters overflowing your buffers == bad
357 if ((value > PRINTF_MAX_FLOAT) || (value < -PRINTF_MAX_FLOAT)) {
358 #if defined(PRINTF_SUPPORT_EXPONENTIAL)
359 return _etoa(out, buffer, idx, maxlen, value, prec, width, flags);
360 #else
361 return 0U;
362 #endif
363 }
364
365 // test for negative
366 bool negative = false;
367 if (value < 0) {
368 negative = true;
369 value = 0 - value;
370 }
371
372 // set default precision, if not set explicitly
373 if (!(flags & FLAGS_PRECISION)) {
374 prec = PRINTF_DEFAULT_FLOAT_PRECISION;
375 }
376 // limit precision to 9, cause a prec >= 10 can lead to overflow errors
377 while ((len < PRINTF_FTOA_BUFFER_SIZE) && (prec > 9U)) {
378 buf[len++] = '0';
379 prec--;
380 }
381
382 int whole = (int)value;
383 double tmp = (value - whole) * pow10[prec];
384 unsigned long frac = (unsigned long)tmp;
385 diff = tmp - frac;
386
387 if (diff > 0.5) {
388 ++frac;
389 // handle rollover, e.g. case 0.99 with prec 1 is 1.0
390 if (frac >= pow10[prec]) {
391 frac = 0;
392 ++whole;
393 }
394 }
395 else if (diff < 0.5) {
396 }
397 else if ((frac == 0U) || (frac & 1U)) {
398 // if halfway, round up if odd OR if last digit is 0
399 ++frac;
400 }
401
402 if (prec == 0U) {
403 diff = value - (double)whole;
404 if ((!(diff < 0.5) || (diff > 0.5)) && (whole & 1)) {
405 // exactly 0.5 and ODD, then round up
406 // 1.5 -> 2, but 2.5 -> 2
407 ++whole;
408 }
409 }
410 else {
411 unsigned int count = prec;
412 // now do fractional part, as an unsigned number
413 while (len < PRINTF_FTOA_BUFFER_SIZE) {
414 --count;
415 buf[len++] = (char)(48U + (frac % 10U));
416 if (!(frac /= 10U)) {
417 break;
418 }
419 }
420 // add extra 0s
421 while ((len < PRINTF_FTOA_BUFFER_SIZE) && (count-- > 0U)) {
422 buf[len++] = '0';
423 }
424 if (len < PRINTF_FTOA_BUFFER_SIZE) {
425 // add decimal
426 buf[len++] = '.';
427 }
428 }
429
430 // do whole part, number is reversed
431 while (len < PRINTF_FTOA_BUFFER_SIZE) {
432 buf[len++] = (char)(48 + (whole % 10));
433 if (!(whole /= 10)) {
434 break;
435 }
436 }
437
438 // pad leading zeros
439 if (!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD)) {
440 if (width && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
441 width--;
442 }
443 while ((len < width) && (len < PRINTF_FTOA_BUFFER_SIZE)) {
444 buf[len++] = '0';
445 }
446 }
447
448 if (len < PRINTF_FTOA_BUFFER_SIZE) {
449 if (negative) {
450 buf[len++] = '-';
451 }
452 else if (flags & FLAGS_PLUS) {
453 buf[len++] = '+'; // ignore the space if the '+' exists
454 }
455 else if (flags & FLAGS_SPACE) {
456 buf[len++] = ' ';
457 }
458 }
459
460 return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
461 }
462
463
464 #if defined(PRINTF_SUPPORT_EXPONENTIAL)
465 // internal ftoa variant for exponential floating-point type, contributed by Martijn Jasperse <m.jasperse@gmail.com>
466 static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)
467 {
468 // check for NaN and special values
469 if ((value != value) || (value > DBL_MAX) || (value < -DBL_MAX)) {
470 return _ftoa(out, buffer, idx, maxlen, value, prec, width, flags);
471 }
472
473 // determine the sign
474 const bool negative = value < 0;
475 if (negative) {
476 value = -value;
477 }
478
479 // default precision
480 if (!(flags & FLAGS_PRECISION)) {
481 prec = PRINTF_DEFAULT_FLOAT_PRECISION;
482 }
483
484 // determine the decimal exponent
485 // based on the algorithm by David Gay (https://www.ampl.com/netlib/fp/dtoa.c)
486 union {
487 uint64_t U;
488 double F;
489 } conv;
490
491 conv.F = value;
492 int exp2 = (int)((conv.U >> 52U) & 0x07FFU) - 1023; // effectively log2
493 conv.U = (conv.U & ((1ULL << 52U) - 1U)) | (1023ULL << 52U); // drop the exponent so conv.F is now in [1,2)
494 // now approximate log10 from the log2 integer part and an expansion of ln around 1.5
495 int expval = (int)(0.1760912590558 + exp2 * 0.301029995663981 + (conv.F - 1.5) * 0.289529654602168);
496 // now we want to compute 10^expval but we want to be sure it won't overflow
497 exp2 = (int)(expval * 3.321928094887362 + 0.5);
498 const double z = expval * 2.302585092994046 - exp2 * 0.6931471805599453;
499 const double z2 = z * z;
500 conv.U = (uint64_t)(exp2 + 1023) << 52U;
501 // compute exp(z) using continued fractions, see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex
502 conv.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14)))));
503 // correct for rounding errors
504 if (value < conv.F) {
505 expval--;
506 conv.F /= 10;
507 }
508
509 // the exponent format is "%+03d" and largest value is "307", so set aside 4-5 characters
510 unsigned int minwidth = ((expval < 100) && (expval > -100)) ? 4U : 5U;
511
512 // in "%g" mode, "prec" is the number of *significant figures* not decimals
513 if (flags & FLAGS_ADAPT_EXP) {
514 // do we want to fall-back to "%f" mode?
515 if ((value >= 1e-4) && (value < 1e6)) {
516 if ((int)prec > expval) {
517 prec = (unsigned)((int)prec - expval - 1);
518 }
519 else {
520 prec = 0;
521 }
522 flags |= FLAGS_PRECISION; // make sure _ftoa respects precision
523 // no characters in exponent
524 minwidth = 0U;
525 expval = 0;
526 }
527 else {
528 // we use one sigfig for the whole part
529 if ((prec > 0) && (flags & FLAGS_PRECISION)) {
530 --prec;
531 }
532 }
533 }
534
535 // will everything fit?
536 unsigned int fwidth = width;
537 if (width > minwidth) {
538 // we didn't fall-back so subtract the characters required for the exponent
539 fwidth -= minwidth;
540 } else {
541 // not enough characters, so go back to default sizing
542 fwidth = 0U;
543 }
544 if ((flags & FLAGS_LEFT) && minwidth) {
545 // if we're padding on the right, DON'T pad the floating part
546 fwidth = 0U;
547 }
548
549 // rescale the float value
550 if (expval) {
551 value /= conv.F;
552 }
553
554 // output the floating part
555 const size_t start_idx = idx;
556 idx = _ftoa(out, buffer, idx, maxlen, negative ? -value : value, prec, fwidth, flags & ~FLAGS_ADAPT_EXP);
557
558 // output the exponent part
559 if (minwidth) {
560 // output the exponential symbol
561 out((flags & FLAGS_UPPERCASE) ? 'E' : 'e', buffer, idx++, maxlen);
562 // output the exponent value
563 idx = _ntoa_long(out, buffer, idx, maxlen, (expval < 0) ? -expval : expval, expval < 0, 10, 0, minwidth-1, FLAGS_ZEROPAD | FLAGS_PLUS);
564 // might need to right-pad spaces
565 if (flags & FLAGS_LEFT) {
566 while (idx - start_idx < width) out(' ', buffer, idx++, maxlen);
567 }
568 }
569 return idx;
570 }
571 #endif // PRINTF_SUPPORT_EXPONENTIAL
572 #endif // PRINTF_SUPPORT_FLOAT
573
574
575 // internal vsnprintf
576 static int _vsnprintf(out_fct_type out, char* buffer, const size_t maxlen, const char* format, va_list va)
577 {
578 unsigned int flags, width, precision, n;
579 size_t idx = 0U;
580
581 if (!buffer) {
582 // use null output function
583 out = _out_null;
584 }
585
586 while (*format)
587 {
588 // format specifier? %[flags][width][.precision][length]
589 if (*format != '%') {
590 // no
591 out(*format, buffer, idx++, maxlen);
592 format++;
593 continue;
594 }
595 else {
596 // yes, evaluate it
597 format++;
598 }
599
600 // evaluate flags
601 flags = 0U;
602 do {
603 switch (*format) {
604 case '0': flags |= FLAGS_ZEROPAD; format++; n = 1U; break;
605 case '-': flags |= FLAGS_LEFT; format++; n = 1U; break;
606 case '+': flags |= FLAGS_PLUS; format++; n = 1U; break;
607 case ' ': flags |= FLAGS_SPACE; format++; n = 1U; break;
608 case '#': flags |= FLAGS_HASH; format++; n = 1U; break;
609 default : n = 0U; break;
610 }
611 } while (n);
612
613 // evaluate width field
614 width = 0U;
615 if (_is_digit(*format)) {
616 width = _atoi(&format);
617 }
618 else if (*format == '*') {
619 const int w = va_arg(va, int);
620 if (w < 0) {
621 flags |= FLAGS_LEFT; // reverse padding
622 width = (unsigned int)-w;
623 }
624 else {
625 width = (unsigned int)w;
626 }
627 format++;
628 }
629
630 // evaluate precision field
631 precision = 0U;
632 if (*format == '.') {
633 flags |= FLAGS_PRECISION;
634 format++;
635 if (_is_digit(*format)) {
636 precision = _atoi(&format);
637 }
638 else if (*format == '*') {
639 const int prec = (int)va_arg(va, int);
640 precision = prec > 0 ? (unsigned int)prec : 0U;
641 format++;
642 }
643 }
644
645 // evaluate length field
646 switch (*format) {
647 case 'l' :
648 flags |= FLAGS_LONG;
649 format++;
650 if (*format == 'l') {
651 flags |= FLAGS_LONG_LONG;
652 format++;
653 }
654 break;
655 case 'h' :
656 flags |= FLAGS_SHORT;
657 format++;
658 if (*format == 'h') {
659 flags |= FLAGS_CHAR;
660 format++;
661 }
662 break;
663 #if defined(PRINTF_SUPPORT_PTRDIFF_T)
664 case 't' :
665 flags |= (sizeof(ptrdiff_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
666 format++;
667 break;
668 #endif
669 case 'j' :
670 flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
671 format++;
672 break;
673 case 'z' :
674 flags |= (sizeof(size_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
675 format++;
676 break;
677 default :
678 break;
679 }
680
681 // evaluate specifier
682 switch (*format) {
683 case 'd' :
684 case 'i' :
685 case 'u' :
686 case 'x' :
687 case 'X' :
688 case 'o' :
689 case 'b' : {
690 // set the base
691 unsigned int base;
692 if (*format == 'x' || *format == 'X') {
693 base = 16U;
694 }
695 else if (*format == 'o') {
696 base = 8U;
697 }
698 else if (*format == 'b') {
699 base = 2U;
700 }
701 else {
702 base = 10U;
703 flags &= ~FLAGS_HASH; // no hash for dec format
704 }
705 // uppercase
706 if (*format == 'X') {
707 flags |= FLAGS_UPPERCASE;
708 }
709
710 // no plus or space flag for u, x, X, o, b
711 if ((*format != 'i') && (*format != 'd')) {
712 flags &= ~(FLAGS_PLUS | FLAGS_SPACE);
713 }
714
715 // ignore '0' flag when precision is given
716 if (flags & FLAGS_PRECISION) {
717 flags &= ~FLAGS_ZEROPAD;
718 }
719
720 // convert the integer
721 if ((*format == 'i') || (*format == 'd')) {
722 // signed
723 if (flags & FLAGS_LONG_LONG) {
724 #if defined(PRINTF_SUPPORT_LONG_LONG)
725 const long long value = va_arg(va, long long);
726 idx = _ntoa_long_long(out, buffer, idx, maxlen, (unsigned long long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
727 #endif
728 }
729 else if (flags & FLAGS_LONG) {
730 const long value = va_arg(va, long);
731 idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
732 }
733 else {
734 const int value = (flags & FLAGS_CHAR) ? (signed char)va_arg(va, int) : (flags & FLAGS_SHORT) ? (short int)va_arg(va, int) : va_arg(va, int);
735 idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned int)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
736 }
737 }
738 else {
739 // unsigned
740 if (flags & FLAGS_LONG_LONG) {
741 #if defined(PRINTF_SUPPORT_LONG_LONG)
742 idx = _ntoa_long_long(out, buffer, idx, maxlen, va_arg(va, unsigned long long), false, base, precision, width, flags);
743 #endif
744 }
745 else if (flags & FLAGS_LONG) {
746 idx = _ntoa_long(out, buffer, idx, maxlen, va_arg(va, unsigned long), false, base, precision, width, flags);
747 }
748 else {
749 const unsigned int value = (flags & FLAGS_CHAR) ? (unsigned char)va_arg(va, unsigned int) : (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(va, unsigned int) : va_arg(va, unsigned int);
750 idx = _ntoa_long(out, buffer, idx, maxlen, value, false, base, precision, width, flags);
751 }
752 }
753 format++;
754 break;
755 }
756 #if defined(PRINTF_SUPPORT_FLOAT)
757 case 'f' :
758 case 'F' :
759 if (*format == 'F') flags |= FLAGS_UPPERCASE;
760 idx = _ftoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
761 format++;
762 break;
763 #if defined(PRINTF_SUPPORT_EXPONENTIAL)
764 case 'e':
765 case 'E':
766 case 'g':
767 case 'G':
768 if ((*format == 'g')||(*format == 'G')) flags |= FLAGS_ADAPT_EXP;
769 if ((*format == 'E')||(*format == 'G')) flags |= FLAGS_UPPERCASE;
770 idx = _etoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
771 format++;
772 break;
773 #endif // PRINTF_SUPPORT_EXPONENTIAL
774 #endif // PRINTF_SUPPORT_FLOAT
775 case 'c' : {
776 unsigned int l = 1U;
777 // pre padding
778 if (!(flags & FLAGS_LEFT)) {
779 while (l++ < width) {
780 out(' ', buffer, idx++, maxlen);
781 }
782 }
783 // char output
784 out((char)va_arg(va, int), buffer, idx++, maxlen);
785 // post padding
786 if (flags & FLAGS_LEFT) {
787 while (l++ < width) {
788 out(' ', buffer, idx++, maxlen);
789 }
790 }
791 format++;
792 break;
793 }
794
795 case 's' : {
796 const char* p = va_arg(va, char*);
797 unsigned int l = _strnlen_s(p, precision ? precision : (size_t)-1);
798 // pre padding
799 if (flags & FLAGS_PRECISION) {
800 l = (l < precision ? l : precision);
801 }
802 if (!(flags & FLAGS_LEFT)) {
803 while (l++ < width) {
804 out(' ', buffer, idx++, maxlen);
805 }
806 }
807 // string output
808 while ((*p != 0) && (!(flags & FLAGS_PRECISION) || precision--)) {
809 out(*(p++), buffer, idx++, maxlen);
810 }
811 // post padding
812 if (flags & FLAGS_LEFT) {
813 while (l++ < width) {
814 out(' ', buffer, idx++, maxlen);
815 }
816 }
817 format++;
818 break;
819 }
820
821 case 'p' : {
822 width = sizeof(void*) * 2U;
823 flags |= FLAGS_ZEROPAD | FLAGS_UPPERCASE;
824 #if defined(PRINTF_SUPPORT_LONG_LONG)
825 const bool is_ll = sizeof(uintptr_t) == sizeof(long long);
826 if (is_ll) {
827 idx = _ntoa_long_long(out, buffer, idx, maxlen, (uintptr_t)va_arg(va, void*), false, 16U, precision, width, flags);
828 }
829 else {
830 #endif
831 idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)((uintptr_t)va_arg(va, void*)), false, 16U, precision, width, flags);
832 #if defined(PRINTF_SUPPORT_LONG_LONG)
833 }
834 #endif
835 format++;
836 break;
837 }
838
839 case '%' :
840 out('%', buffer, idx++, maxlen);
841 format++;
842 break;
843
844 default :
845 out(*format, buffer, idx++, maxlen);
846 format++;
847 break;
848 }
849 }
850
851 // termination
852 out((char)0, buffer, idx < maxlen ? idx : maxlen - 1U, maxlen);
853
854 // return written chars without terminating \0
855 return (int)idx;
856 }
857
858
859 ///////////////////////////////////////////////////////////////////////////////
860
861 int printf_(const char* format, ...)
862 {
863 va_list va;
864 va_start(va, format);
865 char buffer[1];
866 const int ret = _vsnprintf(_out_char, buffer, (size_t)-1, format, va);
867 va_end(va);
868 return ret;
869 }
870
871
872 int sprintf_(char* buffer, const char* format, ...)
873 {
874 va_list va;
875 va_start(va, format);
876 const int ret = _vsnprintf(_out_buffer, buffer, (size_t)-1, format, va);
877 va_end(va);
878 return ret;
879 }
880
881
882 int snprintf_(char* buffer, size_t count, const char* format, ...)
883 {
884 va_list va;
885 va_start(va, format);
886 const int ret = _vsnprintf(_out_buffer, buffer, count, format, va);
887 va_end(va);
888 return ret;
889 }
890
891
892 int vprintf_(const char* format, va_list va)
893 {
894 char buffer[1];
895 return _vsnprintf(_out_char, buffer, (size_t)-1, format, va);
896 }
897
898
899 int vsnprintf_(char* buffer, size_t count, const char* format, va_list va)
900 {
901 return _vsnprintf(_out_buffer, buffer, count, format, va);
902 }
903
904
905 int fctprintf(void (*out)(char character, void* arg), void* arg, const char* format, ...)
906 {
907 va_list va;
908 va_start(va, format);
909 const out_fct_wrap_type out_fct_wrap = { out, arg };
910 const int ret = _vsnprintf(_out_fct, (char*)(uintptr_t)&out_fct_wrap, (size_t)-1, format, va);
911 va_end(va);
912 return ret;
913 }
914
915 int fctvprintf(void (*out)(char character, void* arg), void* arg, const char* format, va_list va)
916 {
917 const out_fct_wrap_type out_fct_wrap = { out, arg };
918 return _vsnprintf(_out_fct, (char*)(uintptr_t)&out_fct_wrap, (size_t)-1, format, va);
919 }
_atoi
static unsigned int _atoi(const char **str)
Definition: printf.c:187
FLAGS_SPACE
#define FLAGS_SPACE
Definition: printf.c:104
FLAGS_HASH
#define FLAGS_HASH
Definition: printf.c:105
FLAGS_ADAPT_EXP
#define FLAGS_ADAPT_EXP
Definition: printf.c:112
_out_rev
static size_t _out_rev(out_fct_type out, char *buffer, size_t idx, size_t maxlen, const char *buf, size_t len, unsigned int width, unsigned int flags)
Definition: printf.c:198
_out_null
static void _out_null(char character, void *buffer, size_t idx, size_t maxlen)
Definition: printf.c:141
_out_buffer
static void _out_buffer(char character, void *buffer, size_t idx, size_t maxlen)
Definition: printf.c:132
_vsnprintf
static int _vsnprintf(out_fct_type out, char *buffer, const size_t maxlen, const char *format, va_list va)
Definition: printf.c:576
_ntoa_long
static size_t _ntoa_long(out_fct_type out, char *buffer, size_t idx, size_t maxlen, unsigned long value, bool negative, unsigned long base, unsigned int prec, unsigned int width, unsigned int flags)
Definition: printf.c:280
out_fct_wrap_type::arg
void * arg
Definition: printf.c:127
vsnprintf_
int vsnprintf_(char *buffer, size_t count, const char *format, va_list va)
Definition: printf.c:899
_putchar
void _putchar(char character)
_out_fct
static void _out_fct(char character, void *buffer, size_t idx, size_t maxlen)
Definition: printf.c:158
out_fct_type
void(* out_fct_type)(char character, void *buffer, size_t idx, size_t maxlen)
Definition: printf.c:121
fctvprintf
int fctvprintf(void(*out)(char character, void *arg), void *arg, const char *format, va_list va)
Definition: printf.c:915
FLAGS_ZEROPAD
#define FLAGS_ZEROPAD
Definition: printf.c:101
PRINTF_FTOA_BUFFER_SIZE
#define PRINTF_FTOA_BUFFER_SIZE
Definition: printf.c:58
FLAGS_PRECISION
#define FLAGS_PRECISION
Definition: printf.c:111
printf.h
FLAGS_SHORT
#define FLAGS_SHORT
Definition: printf.c:108
_etoa
static size_t _etoa(out_fct_type out, char *buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)
Definition: printf.c:466
FLAGS_UPPERCASE
#define FLAGS_UPPERCASE
Definition: printf.c:106
_strnlen_s
static unsigned int _strnlen_s(const char *str, size_t maxsize)
Definition: printf.c:170
vprintf_
int vprintf_(const char *format, va_list va)
Definition: printf.c:892
printf_
int printf_(const char *format,...)
Definition: printf.c:861
FLAGS_LEFT
#define FLAGS_LEFT
Definition: printf.c:102
PRINTF_MAX_FLOAT
#define PRINTF_MAX_FLOAT
Definition: printf.c:82
_ntoa_long_long
static size_t _ntoa_long_long(out_fct_type out, char *buffer, size_t idx, size_t maxlen, unsigned long long value, bool negative, unsigned long long base, unsigned int prec, unsigned int width, unsigned int flags)
Definition: printf.c:305
FLAGS_LONG_LONG
#define FLAGS_LONG_LONG
Definition: printf.c:110
_out_char
static void _out_char(char character, void *buffer, size_t idx, size_t maxlen)
Definition: printf.c:148
FLAGS_PLUS
#define FLAGS_PLUS
Definition: printf.c:103
sprintf_
int sprintf_(char *buffer, const char *format,...)
Definition: printf.c:872
FLAGS_LONG
#define FLAGS_LONG
Definition: printf.c:109
_ftoa
static size_t _ftoa(out_fct_type out, char *buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)
Definition: printf.c:338
PRINTF_NTOA_BUFFER_SIZE
#define PRINTF_NTOA_BUFFER_SIZE
Definition: printf.c:51
snprintf_
int snprintf_(char *buffer, size_t count, const char *format,...)
Definition: printf.c:882
_ntoa_format
static size_t _ntoa_format(out_fct_type out, char *buffer, size_t idx, size_t maxlen, char *buf, size_t len, bool negative, unsigned int base, unsigned int prec, unsigned int width, unsigned int flags)
Definition: printf.c:226
out_fct_wrap_type
Definition: printf.c:125
_is_digit
static bool _is_digit(char ch)
Definition: printf.c:180
FLAGS_CHAR
#define FLAGS_CHAR
Definition: printf.c:107
fctprintf
int fctprintf(void(*out)(char character, void *arg), void *arg, const char *format,...)
Definition: printf.c:905
PRINTF_DEFAULT_FLOAT_PRECISION
#define PRINTF_DEFAULT_FLOAT_PRECISION
Definition: printf.c:76