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
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
28 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
29 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #include "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 #include <limits.h>
46
47 /* for test */
48 /* #define SNPRINTF_TEST 1 */
49 #ifdef SNPRINTF_TEST
50 #define snprintf my_snprintf
51 #define vsnprintf my_vsnprintf
52 #endif /* SNPRINTF_TEST */
53
54 int snprintf(char* str, size_t size, const char* format, ...);
55 int vsnprintf(char* str, size_t size, const char* format, va_list arg);
56
57 /**
58 * Very portable snprintf implementation, limited in functionality,
59 * esp. for %[capital] %[nonportable] and so on. Reduced float functionality,
60 * mostly in formatting and range (e+-16), for %f and %g.
61 *
62 * %s, %d, %u, %i, %x, %c, %n and %% are fully supported.
63 * This includes width, precision, flags 0- +, and *(arg for wid,prec).
64 * %f, %g, %m, %p have reduced support, support for wid,prec,flags,*, but
65 * less floating point range, no %e formatting for %g.
66 */
snprintf(char * str,size_t size,const char * format,...)67 int snprintf(char* str, size_t size, const char* format, ...)
68 {
69 int r;
70 va_list args;
71 va_start(args, format);
72 r = vsnprintf(str, size, format, args);
73 va_end(args);
74 return r;
75 }
76
77 /** add padding to string */
78 static void
print_pad(char ** at,size_t * left,int * ret,char p,int num)79 print_pad(char** at, size_t* left, int* ret, char p, int num)
80 {
81 while(num--) {
82 if(*left > 1) {
83 *(*at)++ = p;
84 (*left)--;
85 }
86 (*ret)++;
87 }
88 }
89
90 /** get negative symbol, 0 if none */
91 static char
get_negsign(int negative,int plus,int space)92 get_negsign(int negative, int plus, int space)
93 {
94 if(negative)
95 return '-';
96 if(plus)
97 return '+';
98 if(space)
99 return ' ';
100 return 0;
101 }
102
103 #define PRINT_DEC_BUFSZ 32 /* 20 is enough for 64 bit decimals */
104 /** print decimal into buffer, returns length */
105 static int
print_dec(char * buf,int max,unsigned int value)106 print_dec(char* buf, int max, unsigned int value)
107 {
108 int i = 0;
109 if(value == 0) {
110 if(max > 0) {
111 buf[0] = '0';
112 i = 1;
113 }
114 } else while(value && i < max) {
115 buf[i++] = '0' + value % 10;
116 value /= 10;
117 }
118 return i;
119 }
120
121 /** print long decimal into buffer, returns length */
122 static int
print_dec_l(char * buf,int max,unsigned long value)123 print_dec_l(char* buf, int max, unsigned long value)
124 {
125 int i = 0;
126 if(value == 0) {
127 if(max > 0) {
128 buf[0] = '0';
129 i = 1;
130 }
131 } else while(value && i < max) {
132 buf[i++] = '0' + value % 10;
133 value /= 10;
134 }
135 return i;
136 }
137
138 /** print long decimal into buffer, returns length */
139 static int
print_dec_ll(char * buf,int max,unsigned long long value)140 print_dec_ll(char* buf, int max, unsigned long long value)
141 {
142 int i = 0;
143 if(value == 0) {
144 if(max > 0) {
145 buf[0] = '0';
146 i = 1;
147 }
148 } else while(value && i < max) {
149 buf[i++] = '0' + value % 10;
150 value /= 10;
151 }
152 return i;
153 }
154
155 /** print hex into buffer, returns length */
156 static int
print_hex(char * buf,int max,unsigned int value)157 print_hex(char* buf, int max, unsigned int value)
158 {
159 const char* h = "0123456789abcdef";
160 int i = 0;
161 if(value == 0) {
162 if(max > 0) {
163 buf[0] = '0';
164 i = 1;
165 }
166 } else while(value && i < max) {
167 buf[i++] = h[value & 0x0f];
168 value >>= 4;
169 }
170 return i;
171 }
172
173 /** print long hex into buffer, returns length */
174 static int
print_hex_l(char * buf,int max,unsigned long value)175 print_hex_l(char* buf, int max, unsigned long value)
176 {
177 const char* h = "0123456789abcdef";
178 int i = 0;
179 if(value == 0) {
180 if(max > 0) {
181 buf[0] = '0';
182 i = 1;
183 }
184 } else while(value && i < max) {
185 buf[i++] = h[value & 0x0f];
186 value >>= 4;
187 }
188 return i;
189 }
190
191 /** print long long hex into buffer, returns length */
192 static int
print_hex_ll(char * buf,int max,unsigned long long value)193 print_hex_ll(char* buf, int max, unsigned long long value)
194 {
195 const char* h = "0123456789abcdef";
196 int i = 0;
197 if(value == 0) {
198 if(max > 0) {
199 buf[0] = '0';
200 i = 1;
201 }
202 } else while(value && i < max) {
203 buf[i++] = h[value & 0x0f];
204 value >>= 4;
205 }
206 return i;
207 }
208
209 /** copy string into result, reversed */
210 static void
spool_str_rev(char ** at,size_t * left,int * ret,const char * buf,int len)211 spool_str_rev(char** at, size_t* left, int* ret, const char* buf, int len)
212 {
213 int i = len;
214 while(i) {
215 if(*left > 1) {
216 *(*at)++ = buf[--i];
217 (*left)--;
218 } else --i;
219 (*ret)++;
220 }
221 }
222
223 /** copy string into result */
224 static void
spool_str(char ** at,size_t * left,int * ret,const char * buf,int len)225 spool_str(char** at, size_t* left, int* ret, const char* buf, int len)
226 {
227 int i;
228 for(i=0; i<len; i++) {
229 if(*left > 1) {
230 *(*at)++ = buf[i];
231 (*left)--;
232 }
233 (*ret)++;
234 }
235 }
236
237 /** print number formatted */
238 static void
print_num(char ** at,size_t * left,int * ret,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space,int zero,int negative,char * buf,int len)239 print_num(char** at, size_t* left, int* ret, int minw, int precision,
240 int prgiven, int zeropad, int minus, int plus, int space,
241 int zero, int negative, char* buf, int len)
242 {
243 int w = len; /* excludes minus sign */
244 char s = get_negsign(negative, plus, space);
245 if(minus) {
246 /* left adjust the number into the field, space padding */
247 /* calc numw = [sign][zeroes][number] */
248 int numw = w;
249 if(precision == 0 && zero) numw = 0;
250 if(numw < precision) numw = precision;
251 if(s) numw++;
252
253 /* sign */
254 if(s) print_pad(at, left, ret, s, 1);
255
256 /* number */
257 if(precision == 0 && zero) {
258 /* "" for the number */
259 } else {
260 if(w < precision)
261 print_pad(at, left, ret, '0', precision - w);
262 spool_str_rev(at, left, ret, buf, len);
263 }
264 /* spaces */
265 if(numw < minw)
266 print_pad(at, left, ret, ' ', minw - numw);
267 } else {
268 /* pad on the left of the number */
269 /* calculate numw has width of [sign][zeroes][number] */
270 int numw = w;
271 if(precision == 0 && zero) numw = 0;
272 if(numw < precision) numw = precision;
273 if(!prgiven && zeropad && numw < minw) numw = minw;
274 else if(s) numw++;
275
276 /* pad with spaces */
277 if(numw < minw)
278 print_pad(at, left, ret, ' ', minw - numw);
279 /* print sign (and one less zeropad if so) */
280 if(s) {
281 print_pad(at, left, ret, s, 1);
282 numw--;
283 }
284 /* pad with zeroes */
285 if(w < numw)
286 print_pad(at, left, ret, '0', numw - w);
287 if(precision == 0 && zero)
288 return;
289 /* print the characters for the value */
290 spool_str_rev(at, left, ret, buf, len);
291 }
292 }
293
294 /** print %d and %i */
295 static void
print_num_d(char ** at,size_t * left,int * ret,int value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)296 print_num_d(char** at, size_t* left, int* ret, int value,
297 int minw, int precision, int prgiven, int zeropad, int minus,
298 int plus, int space)
299 {
300 char buf[PRINT_DEC_BUFSZ];
301 int negative = (value < 0);
302 int zero = (value == 0);
303 int len = print_dec(buf, (int)sizeof(buf),
304 (unsigned int)(negative?-value:value));
305 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
306 plus, space, zero, negative, buf, len);
307 }
308
309 /** print %ld and %li */
310 static void
print_num_ld(char ** at,size_t * left,int * ret,long value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)311 print_num_ld(char** at, size_t* left, int* ret, long value,
312 int minw, int precision, int prgiven, int zeropad, int minus,
313 int plus, int space)
314 {
315 char buf[PRINT_DEC_BUFSZ];
316 int negative = (value < 0);
317 int zero = (value == 0);
318 int len = print_dec_l(buf, (int)sizeof(buf),
319 (unsigned long)(negative?-value:value));
320 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
321 plus, space, zero, negative, buf, len);
322 }
323
324 /** print %lld and %lli */
325 static void
print_num_lld(char ** at,size_t * left,int * ret,long long value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)326 print_num_lld(char** at, size_t* left, int* ret, long long value,
327 int minw, int precision, int prgiven, int zeropad, int minus,
328 int plus, int space)
329 {
330 char buf[PRINT_DEC_BUFSZ];
331 int negative = (value < 0);
332 int zero = (value == 0);
333 int len = print_dec_ll(buf, (int)sizeof(buf),
334 (unsigned long long)(negative?-value:value));
335 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
336 plus, space, zero, negative, buf, len);
337 }
338
339 /** print %u */
340 static void
print_num_u(char ** at,size_t * left,int * ret,unsigned int value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)341 print_num_u(char** at, size_t* left, int* ret, unsigned int value,
342 int minw, int precision, int prgiven, int zeropad, int minus,
343 int plus, int space)
344 {
345 char buf[PRINT_DEC_BUFSZ];
346 int negative = 0;
347 int zero = (value == 0);
348 int len = print_dec(buf, (int)sizeof(buf), value);
349 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
350 plus, space, zero, negative, buf, len);
351 }
352
353 /** print %lu */
354 static void
print_num_lu(char ** at,size_t * left,int * ret,unsigned long value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)355 print_num_lu(char** at, size_t* left, int* ret, unsigned long value,
356 int minw, int precision, int prgiven, int zeropad, int minus,
357 int plus, int space)
358 {
359 char buf[PRINT_DEC_BUFSZ];
360 int negative = 0;
361 int zero = (value == 0);
362 int len = print_dec_l(buf, (int)sizeof(buf), value);
363 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
364 plus, space, zero, negative, buf, len);
365 }
366
367 /** print %llu */
368 static void
print_num_llu(char ** at,size_t * left,int * ret,unsigned long long value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)369 print_num_llu(char** at, size_t* left, int* ret, unsigned long long value,
370 int minw, int precision, int prgiven, int zeropad, int minus,
371 int plus, int space)
372 {
373 char buf[PRINT_DEC_BUFSZ];
374 int negative = 0;
375 int zero = (value == 0);
376 int len = print_dec_ll(buf, (int)sizeof(buf), value);
377 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
378 plus, space, zero, negative, buf, len);
379 }
380
381 /** print %x */
382 static void
print_num_x(char ** at,size_t * left,int * ret,unsigned int value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)383 print_num_x(char** at, size_t* left, int* ret, unsigned int value,
384 int minw, int precision, int prgiven, int zeropad, int minus,
385 int plus, int space)
386 {
387 char buf[PRINT_DEC_BUFSZ];
388 int negative = 0;
389 int zero = (value == 0);
390 int len = print_hex(buf, (int)sizeof(buf), value);
391 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
392 plus, space, zero, negative, buf, len);
393 }
394
395 /** print %lx */
396 static void
print_num_lx(char ** at,size_t * left,int * ret,unsigned long value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)397 print_num_lx(char** at, size_t* left, int* ret, unsigned long value,
398 int minw, int precision, int prgiven, int zeropad, int minus,
399 int plus, int space)
400 {
401 char buf[PRINT_DEC_BUFSZ];
402 int negative = 0;
403 int zero = (value == 0);
404 int len = print_hex_l(buf, (int)sizeof(buf), value);
405 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
406 plus, space, zero, negative, buf, len);
407 }
408
409 /** print %llx */
410 static void
print_num_llx(char ** at,size_t * left,int * ret,unsigned long long value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)411 print_num_llx(char** at, size_t* left, int* ret, unsigned long long value,
412 int minw, int precision, int prgiven, int zeropad, int minus,
413 int plus, int space)
414 {
415 char buf[PRINT_DEC_BUFSZ];
416 int negative = 0;
417 int zero = (value == 0);
418 int len = print_hex_ll(buf, (int)sizeof(buf), value);
419 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
420 plus, space, zero, negative, buf, len);
421 }
422
423 /** print %llp */
424 static void
print_num_llp(char ** at,size_t * left,int * ret,void * value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)425 print_num_llp(char** at, size_t* left, int* ret, void* value,
426 int minw, int precision, int prgiven, int zeropad, int minus,
427 int plus, int space)
428 {
429 char buf[PRINT_DEC_BUFSZ];
430 int negative = 0;
431 int zero = (value == 0);
432 #if defined(SIZE_MAX) && defined(UINT32_MAX) && (UINT32_MAX == SIZE_MAX || INT32_MAX == SIZE_MAX)
433 /* avoid warning about upcast on 32bit systems */
434 unsigned long long llvalue = (unsigned long)value;
435 #else
436 unsigned long long llvalue = (unsigned long long)value;
437 #endif
438 int len = print_hex_ll(buf, (int)sizeof(buf), llvalue);
439 if(zero) {
440 buf[0]=')';
441 buf[1]='l';
442 buf[2]='i';
443 buf[3]='n';
444 buf[4]='(';
445 len = 5;
446 } else {
447 /* put '0x' in front of the (reversed) buffer result */
448 if(len < PRINT_DEC_BUFSZ)
449 buf[len++] = 'x';
450 if(len < PRINT_DEC_BUFSZ)
451 buf[len++] = '0';
452 }
453 print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
454 plus, space, zero, negative, buf, len);
455 }
456
457 #define PRINT_FLOAT_BUFSZ 64 /* xx.yy with 20.20 about the max */
458 /** spool remainder after the decimal point to buffer, in reverse */
459 static int
print_remainder(char * buf,int max,double r,int prec)460 print_remainder(char* buf, int max, double r, int prec)
461 {
462 unsigned long long cap = 1;
463 unsigned long long value;
464 int len, i;
465 if(prec > 19) prec = 19; /* max we can do */
466 if(max < prec) return 0;
467 for(i=0; i<prec; i++) {
468 cap *= 10;
469 }
470 r *= (double)cap;
471 value = (unsigned long long)r;
472 /* see if we need to round up */
473 if(((unsigned long long)((r - (double)value)*10.0)) >= 5) {
474 value++;
475 /* that might carry to numbers before the comma, if so,
476 * just ignore that rounding. failure because 64bitprintout */
477 if(value >= cap)
478 value = cap-1;
479 }
480 len = print_dec_ll(buf, max, value);
481 while(len < prec) { /* pad with zeroes, e.g. if 0.0012 */
482 buf[len++] = '0';
483 }
484 if(len < max)
485 buf[len++] = '.';
486 return len;
487 }
488
489 /** spool floating point to buffer */
490 static int
print_float(char * buf,int max,double value,int prec)491 print_float(char* buf, int max, double value, int prec)
492 {
493 /* as xxx.xxx if prec==0, no '.', with prec decimals after . */
494 /* no conversion for NAN and INF, because we do not want to require
495 linking with -lm. */
496 /* Thus, the conversions use 64bit integers to convert the numbers,
497 * which makes 19 digits before and after the decimal point the max */
498 unsigned long long whole = (unsigned long long)value;
499 double remain = value - (double)whole;
500 int len = 0;
501 if(prec != 0)
502 len = print_remainder(buf, max, remain, prec);
503 len += print_dec_ll(buf+len, max-len, whole);
504 return len;
505 }
506
507 /** print %f */
508 static void
print_num_f(char ** at,size_t * left,int * ret,double value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)509 print_num_f(char** at, size_t* left, int* ret, double value,
510 int minw, int precision, int prgiven, int zeropad, int minus,
511 int plus, int space)
512 {
513 char buf[PRINT_FLOAT_BUFSZ];
514 int negative = (value < 0);
515 int zero = 0;
516 int len;
517 if(!prgiven) precision = 6;
518 len = print_float(buf, (int)sizeof(buf), negative?-value:value,
519 precision);
520 print_num(at, left, ret, minw, 1, 0, zeropad, minus,
521 plus, space, zero, negative, buf, len);
522 }
523
524 /* rudimentary %g support */
525 static int
print_float_g(char * buf,int max,double value,int prec)526 print_float_g(char* buf, int max, double value, int prec)
527 {
528 unsigned long long whole = (unsigned long long)value;
529 double remain = value - (double)whole;
530 int before = 0;
531 int len = 0;
532
533 /* number of digits before the decimal point */
534 while(whole > 0) {
535 before++;
536 whole /= 10;
537 }
538 whole = (unsigned long long)value;
539
540 if(prec > before && remain != 0.0) {
541 /* see if the last decimals are zero, if so, skip them */
542 len = print_remainder(buf, max, remain, prec-before);
543 while(len > 0 && buf[0]=='0') {
544 memmove(buf, buf+1, --len);
545 }
546 }
547 len += print_dec_ll(buf+len, max-len, whole);
548 return len;
549 }
550
551
552 /** print %g */
553 static void
print_num_g(char ** at,size_t * left,int * ret,double value,int minw,int precision,int prgiven,int zeropad,int minus,int plus,int space)554 print_num_g(char** at, size_t* left, int* ret, double value,
555 int minw, int precision, int prgiven, int zeropad, int minus,
556 int plus, int space)
557 {
558 char buf[PRINT_FLOAT_BUFSZ];
559 int negative = (value < 0);
560 int zero = 0;
561 int len;
562 if(!prgiven) precision = 6;
563 if(precision == 0) precision = 1;
564 len = print_float_g(buf, (int)sizeof(buf), negative?-value:value,
565 precision);
566 print_num(at, left, ret, minw, 1, 0, zeropad, minus,
567 plus, space, zero, negative, buf, len);
568 }
569
570
571 /** strnlen (compat implementation) */
572 static int
my_strnlen(const char * s,int max)573 my_strnlen(const char* s, int max)
574 {
575 int i;
576 for(i=0; i<max; i++)
577 if(s[i]==0)
578 return i;
579 return max;
580 }
581
582 /** print %s */
583 static void
print_str(char ** at,size_t * left,int * ret,char * s,int minw,int precision,int prgiven,int minus)584 print_str(char** at, size_t* left, int* ret, char* s,
585 int minw, int precision, int prgiven, int minus)
586 {
587 int w;
588 /* with prec: no more than x characters from this string, stop at 0 */
589 if(prgiven)
590 w = my_strnlen(s, precision);
591 else w = (int)strlen(s); /* up to the nul */
592 if(w < minw && !minus)
593 print_pad(at, left, ret, ' ', minw - w);
594 spool_str(at, left, ret, s, w);
595 if(w < minw && minus)
596 print_pad(at, left, ret, ' ', minw - w);
597 }
598
599 /** print %c */
600 static void
print_char(char ** at,size_t * left,int * ret,int c,int minw,int minus)601 print_char(char** at, size_t* left, int* ret, int c,
602 int minw, int minus)
603 {
604 if(1 < minw && !minus)
605 print_pad(at, left, ret, ' ', minw - 1);
606 print_pad(at, left, ret, c, 1);
607 if(1 < minw && minus)
608 print_pad(at, left, ret, ' ', minw - 1);
609 }
610
611
612 /**
613 * Print to string.
614 * str: string buffer for result. result will be null terminated.
615 * size: size of the buffer. null is put inside buffer.
616 * format: printf format string.
617 * arg: '...' arguments to print.
618 * returns number of characters. a null is printed after this.
619 * return number of bytes that would have been written
620 * if the buffer had been large enough.
621 *
622 * supported format specifiers:
623 * %s, %u, %d, %x, %i, %f, %g, %c, %p, %n.
624 * length: l, ll (for d, u, x).
625 * precision: 6.6d (for d, u, x)
626 * %f, %g precisions, 0.3f
627 * %20s, '.*s'
628 * and %%.
629 */
vsnprintf(char * str,size_t size,const char * format,va_list arg)630 int vsnprintf(char* str, size_t size, const char* format, va_list arg)
631 {
632 char* at = str;
633 size_t left = size;
634 int ret = 0;
635 const char* fmt = format;
636 int conv, minw, precision, prgiven, zeropad, minus, plus, space, length;
637 while(*fmt) {
638 /* copy string before % */
639 while(*fmt && *fmt!='%') {
640 if(left > 1) {
641 *at++ = *fmt++;
642 left--;
643 } else fmt++;
644 ret++;
645 }
646
647 /* see if we are at end */
648 if(!*fmt) break;
649
650 /* fetch next argument % designation from format string */
651 fmt++; /* skip the '%' */
652
653 /********************************/
654 /* get the argument designation */
655 /********************************/
656 /* we must do this vararg stuff inside this function for
657 * portability. Hence, get_designation, and print_designation
658 * are not their own functions. */
659
660 /* printout designation:
661 * conversion specifier: x, d, u, s, c, m, p
662 * flags: # not supported
663 * 0 zeropad (on the left)
664 * - left adjust (right by default)
665 * ' ' printspace for positive number (in - position).
666 * + alwayssign
667 * fieldwidth: [1-9][0-9]* minimum field width.
668 * if this is * then type int next argument specifies the minwidth.
669 * if this is negative, the - flag is set (with positive width).
670 * precision: period[digits]*, %.2x.
671 * if this is * then type int next argument specifies the precision.
672 * just '.' or negative value means precision=0.
673 * this is mindigits to print for d, i, u, x
674 * this is aftercomma digits for f
675 * this is max number significant digits for g
676 * maxnumber characters to be printed for s
677 * length: 0-none (int), 1-l (long), 2-ll (long long)
678 * notsupported: hh (char), h (short), L (long double), q, j, z, t
679 * Does not support %m$ and *m$ argument designation as array indices.
680 * Does not support %#x
681 *
682 */
683 minw = 0;
684 precision = 1;
685 prgiven = 0;
686 zeropad = 0;
687 minus = 0;
688 plus = 0;
689 space = 0;
690 length = 0;
691
692 /* get flags in any order */
693 for(;;) {
694 if(*fmt == '0')
695 zeropad = 1;
696 else if(*fmt == '-')
697 minus = 1;
698 else if(*fmt == '+')
699 plus = 1;
700 else if(*fmt == ' ')
701 space = 1;
702 else break;
703 fmt++;
704 }
705
706 /* field width */
707 if(*fmt == '*') {
708 fmt++; /* skip char */
709 minw = va_arg(arg, int);
710 if(minw < 0) {
711 minus = 1;
712 minw = -minw;
713 }
714 } else while(*fmt >= '0' && *fmt <= '9') {
715 minw = minw*10 + (*fmt++)-'0';
716 }
717
718 /* precision */
719 if(*fmt == '.') {
720 fmt++; /* skip period */
721 prgiven = 1;
722 precision = 0;
723 if(*fmt == '*') {
724 fmt++; /* skip char */
725 precision = va_arg(arg, int);
726 if(precision < 0)
727 precision = 0;
728 } else while(*fmt >= '0' && *fmt <= '9') {
729 precision = precision*10 + (*fmt++)-'0';
730 }
731 }
732
733 /* length */
734 if(*fmt == 'l') {
735 fmt++; /* skip char */
736 length = 1;
737 if(*fmt == 'l') {
738 fmt++; /* skip char */
739 length = 2;
740 }
741 }
742
743 /* get the conversion */
744 if(!*fmt) conv = 0;
745 else conv = *fmt++;
746
747 /***********************************/
748 /* print that argument designation */
749 /***********************************/
750 switch(conv) {
751 case 'i':
752 case 'd':
753 if(length == 0)
754 print_num_d(&at, &left, &ret, va_arg(arg, int),
755 minw, precision, prgiven, zeropad, minus, plus, space);
756 else if(length == 1)
757 print_num_ld(&at, &left, &ret, va_arg(arg, long),
758 minw, precision, prgiven, zeropad, minus, plus, space);
759 else if(length == 2)
760 print_num_lld(&at, &left, &ret,
761 va_arg(arg, long long),
762 minw, precision, prgiven, zeropad, minus, plus, space);
763 break;
764 case 'u':
765 if(length == 0)
766 print_num_u(&at, &left, &ret,
767 va_arg(arg, unsigned int),
768 minw, precision, prgiven, zeropad, minus, plus, space);
769 else if(length == 1)
770 print_num_lu(&at, &left, &ret,
771 va_arg(arg, unsigned long),
772 minw, precision, prgiven, zeropad, minus, plus, space);
773 else if(length == 2)
774 print_num_llu(&at, &left, &ret,
775 va_arg(arg, unsigned long long),
776 minw, precision, prgiven, zeropad, minus, plus, space);
777 break;
778 case 'x':
779 if(length == 0)
780 print_num_x(&at, &left, &ret,
781 va_arg(arg, unsigned int),
782 minw, precision, prgiven, zeropad, minus, plus, space);
783 else if(length == 1)
784 print_num_lx(&at, &left, &ret,
785 va_arg(arg, unsigned long),
786 minw, precision, prgiven, zeropad, minus, plus, space);
787 else if(length == 2)
788 print_num_llx(&at, &left, &ret,
789 va_arg(arg, unsigned long long),
790 minw, precision, prgiven, zeropad, minus, plus, space);
791 break;
792 case 's':
793 print_str(&at, &left, &ret, va_arg(arg, char*),
794 minw, precision, prgiven, minus);
795 break;
796 case 'c':
797 print_char(&at, &left, &ret, va_arg(arg, int),
798 minw, minus);
799 break;
800 case 'n':
801 /* unsupported to harden against format string
802 * exploitation,
803 * handled like an unknown format specifier. */
804 /* *va_arg(arg, int*) = ret; */
805 break;
806 case 'm':
807 print_str(&at, &left, &ret, strerror(errno),
808 minw, precision, prgiven, minus);
809 break;
810 case 'p':
811 print_num_llp(&at, &left, &ret, va_arg(arg, void*),
812 minw, precision, prgiven, zeropad, minus, plus, space);
813 break;
814 case '%':
815 print_pad(&at, &left, &ret, '%', 1);
816 break;
817 case 'f':
818 print_num_f(&at, &left, &ret, va_arg(arg, double),
819 minw, precision, prgiven, zeropad, minus, plus, space);
820 break;
821 case 'g':
822 print_num_g(&at, &left, &ret, va_arg(arg, double),
823 minw, precision, prgiven, zeropad, minus, plus, space);
824 break;
825 /* unknown */
826 default:
827 case 0: break;
828 }
829 }
830
831 /* zero terminate */
832 if(left > 0)
833 *at = 0;
834 return ret;
835 }
836
837 #ifdef SNPRINTF_TEST
838
839 /** do tests */
840 #undef snprintf
841 #define DOTEST(bufsz, result, retval, ...) do { \
842 char buf[bufsz]; \
843 printf("now test %s\n", #__VA_ARGS__); \
844 int r=my_snprintf(buf, sizeof(buf), __VA_ARGS__); \
845 if(r != retval || strcmp(buf, result) != 0) { \
846 printf("error test(%s) was \"%s\":%d\n", \
847 ""#bufsz", "#result", "#retval", "#__VA_ARGS__, \
848 buf, r); \
849 exit(1); \
850 } \
851 r=snprintf(buf, sizeof(buf), __VA_ARGS__); \
852 if(r != retval || strcmp(buf, result) != 0) { \
853 printf("error test(%s) differs with system, \"%s\":%d\n", \
854 ""#bufsz", "#result", "#retval", "#__VA_ARGS__, \
855 buf, r); \
856 exit(1); \
857 } \
858 printf("test(\"%s\":%d) passed\n", buf, r); \
859 } while(0);
860
861 /** test program */
main(void)862 int main(void)
863 {
864 int x = 0;
865
866 /* bufsize, expectedstring, expectedretval, snprintf arguments */
867 DOTEST(1024, "hello", 5, "hello");
868 DOTEST(1024, "h", 1, "h");
869 /* warning from gcc for format string, but it does work
870 * DOTEST(1024, "", 0, ""); */
871
872 DOTEST(3, "he", 5, "hello");
873 DOTEST(1, "", 7, "%d", 7823089);
874
875 /* test positive numbers */
876 DOTEST(1024, "0", 1, "%d", 0);
877 DOTEST(1024, "1", 1, "%d", 1);
878 DOTEST(1024, "9", 1, "%d", 9);
879 DOTEST(1024, "15", 2, "%d", 15);
880 DOTEST(1024, "ab15cd", 6, "ab%dcd", 15);
881 DOTEST(1024, "167", 3, "%d", 167);
882 DOTEST(1024, "7823089", 7, "%d", 7823089);
883 DOTEST(1024, " 12", 3, "%3d", 12);
884 DOTEST(1024, "012", 3, "%.3d", 12);
885 DOTEST(1024, "012", 3, "%3.3d", 12);
886 DOTEST(1024, "012", 3, "%03d", 12);
887 DOTEST(1024, " 012", 4, "%4.3d", 12);
888 DOTEST(1024, "", 0, "%.0d", 0);
889
890 /* test negative numbers */
891 DOTEST(1024, "-1", 2, "%d", -1);
892 DOTEST(1024, "-12", 3, "%3d", -12);
893 DOTEST(1024, " -2", 3, "%3d", -2);
894 DOTEST(1024, "-012", 4, "%.3d", -12);
895 DOTEST(1024, "-012", 4, "%3.3d", -12);
896 DOTEST(1024, "-012", 4, "%4.3d", -12);
897 DOTEST(1024, " -012", 5, "%5.3d", -12);
898 DOTEST(1024, "-12", 3, "%03d", -12);
899 DOTEST(1024, "-02", 3, "%03d", -2);
900 DOTEST(1024, "-15", 3, "%d", -15);
901 DOTEST(1024, "-7307", 5, "%d", -7307);
902 DOTEST(1024, "-12 ", 5, "%-5d", -12);
903 DOTEST(1024, "-00012", 6, "%-.5d", -12);
904
905 /* test + and space flags */
906 DOTEST(1024, "+12", 3, "%+d", 12);
907 DOTEST(1024, " 12", 3, "% d", 12);
908
909 /* test %u */
910 DOTEST(1024, "12", 2, "%u", 12);
911 DOTEST(1024, "0", 1, "%u", 0);
912 DOTEST(1024, "4294967295", 10, "%u", 0xffffffff);
913
914 /* test %x */
915 DOTEST(1024, "0", 1, "%x", 0);
916 DOTEST(1024, "c", 1, "%x", 12);
917 DOTEST(1024, "12ab34cd", 8, "%x", 0x12ab34cd);
918
919 /* test %llu, %lld */
920 DOTEST(1024, "18446744073709551615", 20, "%llu",
921 (long long)0xffffffffffffffff);
922 DOTEST(1024, "-9223372036854775808", 20, "%lld",
923 (long long)0x8000000000000000);
924 DOTEST(1024, "9223372036854775808", 19, "%llu",
925 (long long)0x8000000000000000);
926
927 /* test %s */
928 DOTEST(1024, "hello", 5, "%s", "hello");
929 DOTEST(1024, " hello", 10, "%10s", "hello");
930 DOTEST(1024, "hello ", 10, "%-10s", "hello");
931 DOTEST(1024, "he", 2, "%.2s", "hello");
932 DOTEST(1024, " he", 4, "%4.2s", "hello");
933 DOTEST(1024, " h", 4, "%4.2s", "h");
934
935 /* test %c */
936 DOTEST(1024, "a", 1, "%c", 'a');
937 /* warning from gcc for format string, but it does work
938 DOTEST(1024, " a", 5, "%5c", 'a');
939 DOTEST(1024, "a", 1, "%.0c", 'a'); */
940
941 /* test %n */
942 DOTEST(1024, "hello", 5, "hello%n", &x);
943 if(x != 5) { printf("the %%n failed\n"); exit(1); }
944
945 /* test %m */
946 errno = 0;
947 DOTEST(1024, "Success", 7, "%m");
948
949 /* test %p */
950 DOTEST(1024, "0x10", 4, "%p", (void*)0x10);
951 DOTEST(1024, "(nil)", 5, "%p", (void*)0x0);
952
953 /* test %% */
954 DOTEST(1024, "%", 1, "%%");
955
956 /* test %f */
957 DOTEST(1024, "0.000000", 8, "%f", 0.0);
958 DOTEST(1024, "0.00", 4, "%.2f", 0.0);
959 /* differs, "-0.00" DOTEST(1024, "0.00", 4, "%.2f", -0.0); */
960 DOTEST(1024, "234.00", 6, "%.2f", 234.005);
961 DOTEST(1024, "8973497.1246", 12, "%.4f", 8973497.12456);
962 DOTEST(1024, "-12.000000", 10, "%f", -12.0);
963 DOTEST(1024, "6", 1, "%.0f", 6.0);
964
965 DOTEST(1024, "6", 1, "%g", 6.0);
966 DOTEST(1024, "6.1", 3, "%g", 6.1);
967 DOTEST(1024, "6.15", 4, "%g", 6.15);
968
969 /* These format strings are from the code of NSD, Unbound, ldns */
970
971 DOTEST(1024, "abcdef", 6, "%s", "abcdef");
972 DOTEST(1024, "005", 3, "%03u", 5);
973 DOTEST(1024, "12345", 5, "%03u", 12345);
974 DOTEST(1024, "5", 1, "%d", 5);
975 DOTEST(1024, "(nil)", 5, "%p", NULL);
976 DOTEST(1024, "12345", 5, "%ld", (long)12345);
977 DOTEST(1024, "12345", 5, "%lu", (long)12345);
978 DOTEST(1024, " 12345", 12, "%12u", (unsigned)12345);
979 DOTEST(1024, "12345", 5, "%u", (unsigned)12345);
980 DOTEST(1024, "12345", 5, "%llu", (unsigned long long)12345);
981 DOTEST(1024, "12345", 5, "%x", 0x12345);
982 DOTEST(1024, "12345", 5, "%llx", (long long)0x12345);
983 DOTEST(1024, "012345", 6, "%6.6d", 12345);
984 DOTEST(1024, "012345", 6, "%6.6u", 12345);
985 DOTEST(1024, "1234.54", 7, "%g", 1234.54);
986 DOTEST(1024, "123456789.54", 12, "%.12g", 123456789.54);
987 DOTEST(1024, "3456789123456.54", 16, "%.16g", 3456789123456.54);
988 /* %24g does not work with 24 digits, not enough accuracy,
989 * the first 16 digits are correct */
990 DOTEST(1024, "12345", 5, "%3.3d", 12345);
991 DOTEST(1024, "000", 3, "%3.3d", 0);
992 DOTEST(1024, "001", 3, "%3.3d", 1);
993 DOTEST(1024, "012", 3, "%3.3d", 12);
994 DOTEST(1024, "-012", 4, "%3.3d", -12);
995 DOTEST(1024, "he", 2, "%.2s", "hello");
996 DOTEST(1024, "helloworld", 10, "%s%s", "hello", "world");
997 DOTEST(1024, "he", 2, "%.*s", 2, "hello");
998 DOTEST(1024, " hello", 7, "%*s", 7, "hello");
999 DOTEST(1024, "hello ", 7, "%*s", -7, "hello");
1000 DOTEST(1024, "0", 1, "%c", '0');
1001 DOTEST(1024, "A", 1, "%c", 'A');
1002 DOTEST(1024, "", 1, "%c", 0);
1003 DOTEST(1024, "\010", 1, "%c", 8);
1004 DOTEST(1024, "%", 1, "%%");
1005 DOTEST(1024, "0a", 2, "%02x", 0x0a);
1006 DOTEST(1024, "bd", 2, "%02x", 0xbd);
1007 DOTEST(1024, "12", 2, "%02ld", (long)12);
1008 DOTEST(1024, "02", 2, "%02ld", (long)2);
1009 DOTEST(1024, "02", 2, "%02u", (unsigned)2);
1010 DOTEST(1024, "765432", 6, "%05u", (unsigned)765432);
1011 DOTEST(1024, "10.234", 6, "%0.3f", 10.23421);
1012 DOTEST(1024, "123456.234", 10, "%0.3f", 123456.23421);
1013 DOTEST(1024, "123456789.234", 13, "%0.3f", 123456789.23421);
1014 DOTEST(1024, "123456.23", 9, "%.2f", 123456.23421);
1015 DOTEST(1024, "123456", 6, "%.0f", 123456.23421);
1016 DOTEST(1024, "0123", 4, "%.4x", 0x0123);
1017 DOTEST(1024, "00000123", 8, "%.8x", 0x0123);
1018 DOTEST(1024, "ffeb0cde", 8, "%.8x", 0xffeb0cde);
1019 DOTEST(1024, " 987654321", 10, "%10lu", (unsigned long)987654321);
1020 DOTEST(1024, " 987654321", 12, "%12lu", (unsigned long)987654321);
1021 DOTEST(1024, "987654321", 9, "%i", 987654321);
1022 DOTEST(1024, "-87654321", 9, "%i", -87654321);
1023 DOTEST(1024, "hello ", 16, "%-16s", "hello");
1024 DOTEST(1024, " ", 16, "%-16s", "");
1025 DOTEST(1024, "a ", 16, "%-16s", "a");
1026 DOTEST(1024, "foobarfoobar ", 16, "%-16s", "foobarfoobar");
1027 DOTEST(1024, "foobarfoobarfoobar", 18, "%-16s", "foobarfoobarfoobar");
1028
1029 /* combined expressions */
1030 DOTEST(1024, "foo 1.0 size 512 edns", 21,
1031 "foo %s size %d %s%s", "1.0", 512, "", "edns");
1032 DOTEST(15, "foo 1.0 size 5", 21,
1033 "foo %s size %d %s%s", "1.0", 512, "", "edns");
1034 DOTEST(1024, "packet 1203ceff id", 18,
1035 "packet %2.2x%2.2x%2.2x%2.2x id", 0x12, 0x03, 0xce, 0xff);
1036 DOTEST(1024, "/tmp/testbound_123abcd.tmp", 26, "/tmp/testbound_%u%s%s.tmp", 123, "ab", "cd");
1037
1038 return 0;
1039 }
1040 #endif /* SNPRINTF_TEST */
1041