1 /*
2 * This is the vsnprintf for scummvm/symbian implementation from the original snprintf.c,
3 * all support functions has been removed and vsnprintf renamed to symbian_vsnprintf
4 * snprintf.c - a portable implementation of snprintf
5 * According to the homepage this function could be licensed as either Frontier Aritistic or GPL.
6 *
7 * AUTHOR
8 * Mark Martinec <mark.martinec@ijs.si>, April 1999.
9 *
10 * Copyright 1999, Mark Martinec. All rights reserved.
11 *
12 * TERMS AND CONDITIONS
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the "Frontier Artistic License" which comes
15 * with this Kit.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty
19 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
20 * See the Frontier Artistic License for more details.
21 *
22 * You should have received a copy of the Frontier Artistic License
23 * with this Kit in the file named LICENSE.txt .
24 * If not, I'll be glad to provide one.
25 *
26 * FEATURES
27 * - careful adherence to specs regarding flags, field width and precision;
28 * - good performance for large string handling (large format, large
29 * argument or large paddings). Performance is similar to system's sprintf
30 * and in several cases significantly better (make sure you compile with
31 * optimizations turned on, tell the compiler the code is strict ANSI
32 * if necessary to give it more freedom for optimizations);
33 * - return value semantics per ISO/IEC 9899:1999 ("ISO C99");
34 * - written in standard ISO/ANSI C - requires an ANSI C compiler.
35 *
36 * SUPPORTED CONVERSION SPECIFIERS AND DATA TYPES
37 *
38 * This snprintf only supports the following conversion specifiers:
39 * s, c, d, u, o, x, X, p (and synonyms: i, D, U, O - see below)
40 * with flags: '-', '+', ' ', '0' and '#'.
41 * An asterisk is supported for field width as well as precision.
42 *
43 * Length modifiers 'h' (short int), 'l' (long int),
44 * and 'll' (long long int) are supported.
45 * NOTE:
46 * If macro SNPRINTF_LONGLONG_SUPPORT is not defined (default) the
47 * length modifier 'll' is recognized but treated the same as 'l',
48 * which may cause argument value truncation! Defining
49 * SNPRINTF_LONGLONG_SUPPORT requires that your system's sprintf also
50 * handles length modifier 'll'. long long int is a language extension
51 * which may not be portable.
52 *
53 * Conversion of numeric data (conversion specifiers d, u, o, x, X, p)
54 * with length modifiers (none or h, l, ll) is left to the system routine
55 * sprintf, but all handling of flags, field width and precision as well as
56 * c and s conversions is done very carefully by this portable routine.
57 * If a string precision (truncation) is specified (e.g. %.8s) it is
58 * guaranteed the string beyond the specified precision will not be referenced.
59 *
60 * Length modifiers h, l and ll are ignored for c and s conversions (data
61 * types wint_t and wchar_t are not supported).
62 *
63 * The following common synonyms for conversion characters are supported:
64 * - i is a synonym for d
65 * - D is a synonym for ld, explicit length modifiers are ignored
66 * - U is a synonym for lu, explicit length modifiers are ignored
67 * - O is a synonym for lo, explicit length modifiers are ignored
68 * The D, O and U conversion characters are nonstandard, they are supported
69 * for backward compatibility only, and should not be used for new code.
70 *
71 * The following is specifically NOT supported:
72 * - flag ' (thousands' grouping character) is recognized but ignored
73 * - numeric conversion specifiers: f, e, E, g, G and synonym F,
74 * as well as the new a and A conversion specifiers
75 * - length modifier 'L' (long double) and 'q' (quad - use 'll' instead)
76 * - wide character/string conversions: lc, ls, and nonstandard
77 * synonyms C and S
78 * - writeback of converted string length: conversion character n
79 * - the n$ specification for direct reference to n-th argument
80 * - locales
81 *
82 * It is permitted for str_m to be zero, and it is permitted to specify NULL
83 * pointer for resulting string argument if str_m is zero (as per ISO C99).
84 *
85 * The return value is the number of characters which would be generated
86 * for the given input, excluding the trailing null. If this value
87 * is greater or equal to str_m, not all characters from the result
88 * have been stored in str, output bytes beyond the (str_m-1) -th character
89 * are discarded. If str_m is greater than zero it is guaranteed
90 * the resulting string will be null-terminated.
91 *
92 * NOTE that this matches the ISO C99, OpenBSD, and GNU C library 2.1,
93 * but is different from some older and vendor implementations,
94 * and is also different from XPG, XSH5, SUSv2 specifications.
95 * For historical discussion on changes in the semantics and standards
96 * of snprintf see printf(3) man page in the Linux programmers manual.
97 *
98 * Routines asprintf and vasprintf return a pointer (in the ptr argument)
99 * to a buffer sufficiently large to hold the resulting string. This pointer
100 * should be passed to free(3) to release the allocated storage when it is
101 * no longer needed. If sufficient space cannot be allocated, these functions
102 * will return -1 and set ptr to be a NULL pointer. These two routines are a
103 * GNU C library extensions (glibc).
104 *
105 * Routines asnprintf and vasnprintf are similar to asprintf and vasprintf,
106 * yet, like snprintf and vsnprintf counterparts, will write at most str_m-1
107 * characters into the allocated output string, the last character in the
108 * allocated buffer then gets the terminating null. If the formatted string
109 * length (the return value) is greater than or equal to the str_m argument,
110 * the resulting string was truncated and some of the formatted characters
111 * were discarded. These routines present a handy way to limit the amount
112 * of allocated memory to some sane value.
113 *
114 * AVAILABILITY
115 * http://www.ijs.si/software/snprintf/
116 *
117 * REVISION HISTORY
118 * 1999-04 V0.9 Mark Martinec
119 * - initial version, some modifications after comparing printf
120 * man pages for Digital Unix 4.0, Solaris 2.6 and HPUX 10,
121 * and checking how Perl handles sprintf (differently!);
122 * 1999-04-09 V1.0 Mark Martinec <mark.martinec@ijs.si>
123 * - added main test program, fixed remaining inconsistencies,
124 * added optional (long long int) support;
125 * 1999-04-12 V1.1 Mark Martinec <mark.martinec@ijs.si>
126 * - support the 'p' conversion (pointer to void);
127 * - if a string precision is specified
128 * make sure the string beyond the specified precision
129 * will not be referenced (e.g. by strlen);
130 * 1999-04-13 V1.2 Mark Martinec <mark.martinec@ijs.si>
131 * - support synonyms %D=%ld, %U=%lu, %O=%lo;
132 * - speed up the case of long format string with few conversions;
133 * 1999-06-30 V1.3 Mark Martinec <mark.martinec@ijs.si>
134 * - fixed runaway loop (eventually crashing when str_l wraps
135 * beyond 2^31) while copying format string without
136 * conversion specifiers to a buffer that is too short
137 * (thanks to Edwin Young <edwiny@autonomy.com> for
138 * spotting the problem);
139 * - added macros PORTABLE_SNPRINTF_VERSION_(MAJOR|MINOR)
140 * to snprintf.h
141 * 2000-02-14 V2.0 (never released) Mark Martinec <mark.martinec@ijs.si>
142 * - relaxed license terms: The Artistic License now applies.
143 * You may still apply the GNU GENERAL PUBLIC LICENSE
144 * as was distributed with previous versions, if you prefer;
145 * - changed REVISION HISTORY dates to use ISO 8601 date format;
146 * - added vsnprintf (patch also independently proposed by
147 * Caolan McNamara 2000-05-04, and Keith M Willenson 2000-06-01)
148 * 2000-06-27 V2.1 Mark Martinec <mark.martinec@ijs.si>
149 * - removed POSIX check for str_m<1; value 0 for str_m is
150 * allowed by ISO C99 (and GNU C library 2.1) - (pointed out
151 * on 2000-05-04 by Caolan McNamara, caolan@ csn dot ul dot ie).
152 * Besides relaxed license this change in standards adherence
153 * is the main reason to bump up the major version number;
154 * - added nonstandard routines asnprintf, vasnprintf, asprintf,
155 * vasprintf that dynamically allocate storage for the
156 * resulting string; these routines are not compiled by default,
157 * see comments where NEED_V?ASN?PRINTF macros are defined;
158 * - autoconf contributed by Caolan McNamara
159 * 2000-10-06 V2.2 Mark Martinec <mark.martinec@ijs.si>
160 * - BUG FIX: the %c conversion used a temporary variable
161 * that was no longer in scope when referenced,
162 * possibly causing incorrect resulting character;
163 * - BUG FIX: make precision and minimal field width unsigned
164 * to handle huge values (2^31 <= n < 2^32) correctly;
165 * also be more careful in the use of signed/unsigned/size_t
166 * internal variables - probably more careful than many
167 * vendor implementations, but there may still be a case
168 * where huge values of str_m, precision or minimal field
169 * could cause incorrect behaviour;
170 * - use separate variables for signed/unsigned arguments,
171 * and for short/int, long, and long long argument lengths
172 * to avoid possible incompatibilities on certain
173 * computer architectures. Also use separate variable
174 * arg_sign to hold sign of a numeric argument,
175 * to make code more transparent;
176 * - some fiddling with zero padding and "0x" to make it
177 * Linux compatible;
178 * - systematically use macros fast_memcpy and fast_memset
179 * instead of case-by-case hand optimization; determine some
180 * breakeven string lengths for different architectures;
181 * - terminology change: 'format' -> 'conversion specifier',
182 * 'C9x' -> 'ISO/IEC 9899:1999 ("ISO C99")',
183 * 'alternative form' -> 'alternate form',
184 * 'data type modifier' -> 'length modifier';
185 * - several comments rephrased and new ones added;
186 * - make compiler not complain about 'credits' defined but
187 * not used;
188 */
189 /* ============================================= */
190 /* NO USER SERVICABLE PARTS FOLLOWING THIS POINT */
191 /* ============================================= */
192
193 #define PORTABLE_SNPRINTF_VERSION_MAJOR 2
194 #define PORTABLE_SNPRINTF_VERSION_MINOR 2
195 #include <sys/types.h>
196 #include <string.h>
197 #include <stdlib.h>
198 #include <stdio.h>
199 #include <stdarg.h>
200 #include <assert.h>
201 #include <errno.h>
202 #ifdef isdigit
203 #undef isdigit
204 #endif
205 #define isdigit(c) ((c) >= '0' && (c) <= '9')
206
207 #ifndef breakeven_point
208 # define breakeven_point 6 /* some reasonable one-size-fits-all value */
209 #endif
210
211 #define fast_memcpy(d,s,n) \
212 { register size_t nn = (size_t)(n); \
213 if (nn >= breakeven_point) memcpy((d), (s), nn); \
214 else if (nn > 0) { /* proc call overhead is worth only for large strings*/\
215 register char *dd; register const char *ss; \
216 for (ss=(s), dd=(d); nn>0; nn--) *dd++ = *ss++; } }
217
218 #define fast_memset(d,c,n) \
219 { register size_t nn = (size_t)(n); \
220 if (nn >= breakeven_point) memset((d), (int)(c), nn); \
221 else if (nn > 0) { /* proc call overhead is worth only for large strings*/\
222 register char *dd; register const int cc=(int)(c); \
223 for (dd=(d); nn>0; nn--) *dd++ = cc; } }
224
225
226 /* declarations */
227
228 static char credits[] = "\n\
229 @(#)snprintf.c, v2.2: Mark Martinec, <mark.martinec@ijs.si>\n\
230 @(#)snprintf.c, v2.2: Copyright 1999, Mark Martinec. Frontier Artistic License applies.\n\
231 @(#)snprintf.c, v2.2: http://www.ijs.si/software/snprintf/\n";
vsnprintf(char * str,size_t str_m,const char * fmt,va_list ap)232 int vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap) {
233
234 size_t str_l = 0;
235 const char *p = fmt;
236
237 /* In contrast with POSIX, the ISO C99 now says
238 * that str can be NULL and str_m can be 0.
239 * This is more useful than the old: if (str_m < 1) return -1; */
240
241 if (!p) p = "";
242 while (*p) {
243 if (*p != '%') {
244 /* if (str_l < str_m) str[str_l++] = *p++; -- this would be sufficient */
245 /* but the following code achieves better performance for cases
246 * where format string is long and contains few conversions */
247 const char *q = strchr(p+1,'%');
248 size_t n = !q ? strlen(p) : (q-p);
249 if (str_l < str_m) {
250 size_t avail = str_m-str_l;
251 fast_memcpy(str+str_l, p, (n>avail?avail:n));
252 }
253 p += n; str_l += n;
254 } else {
255 const char *starting_p;
256 size_t min_field_width = 0, precision = 0;
257 int zero_padding = 0, precision_specified = 0, justify_left = 0;
258 int alternate_form = 0, force_sign = 0;
259 int space_for_positive = 1; /* If both the ' ' and '+' flags appear,
260 the ' ' flag should be ignored. */
261 char length_modifier = '\0'; /* allowed values: \0, h, l, L */
262 char tmp[32];/* temporary buffer for simple numeric->string conversion */
263
264 const char *str_arg; /* string address in case of string argument */
265 size_t str_arg_l; /* natural field width of arg without padding
266 and sign */
267 unsigned char uchar_arg;
268 /* unsigned char argument value - only defined for c conversion.
269 N.B. standard explicitly states the char argument for
270 the c conversion is unsigned */
271
272 size_t number_of_zeros_to_pad = 0;
273 /* number of zeros to be inserted for numeric conversions
274 as required by the precision or minimal field width */
275
276 size_t zero_padding_insertion_ind = 0;
277 /* index into tmp where zero padding is to be inserted */
278
279 char fmt_spec = '\0';
280 /* current conversion specifier character */
281
282 str_arg = credits;/* just to make compiler happy (defined but not used)*/
283 str_arg = NULL;
284 starting_p = p; p++; /* skip '%' */
285 /* parse flags */
286 while (*p == '0' || *p == '-' || *p == '+' ||
287 *p == ' ' || *p == '#' || *p == '\'') {
288 switch (*p) {
289 case '0': zero_padding = 1; break;
290 case '-': justify_left = 1; break;
291 case '+': force_sign = 1; space_for_positive = 0; break;
292 case ' ': force_sign = 1;
293 /* If both the ' ' and '+' flags appear, the ' ' flag should be ignored */
294 break;
295 case '#': alternate_form = 1; break;
296 case '\'': break;
297 }
298 p++;
299 }
300 /* If the '0' and '-' flags both appear, the '0' flag should be ignored. */
301
302 /* parse field width */
303 if (*p == '*') {
304 int j;
305 p++; j = va_arg(ap, int);
306 if (j >= 0) min_field_width = j;
307 else { min_field_width = -j; justify_left = 1; }
308 } else if (isdigit((int)(*p))) {
309 /* size_t could be wider than unsigned int;
310 make sure we treat argument like common implementations do */
311 unsigned int uj = *p++ - '0';
312 while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
313 min_field_width = uj;
314 }
315 /* parse precision */
316 if (*p == '.') {
317 p++; precision_specified = 1;
318 if (*p == '*') {
319 int j = va_arg(ap, int);
320 p++;
321 if (j >= 0) precision = j;
322 else {
323 precision_specified = 0; precision = 0;
324 /* NOTE:
325 * Solaris 2.6 man page claims that in this case the precision
326 * should be set to 0. Digital Unix 4.0, HPUX 10 and BSD man page
327 * claim that this case should be treated as unspecified precision,
328 * which is what we do here.
329 */
330 }
331 } else if (isdigit((int)(*p))) {
332 /* size_t could be wider than unsigned int;
333 make sure we treat argument like common implementations do */
334 unsigned int uj = *p++ - '0';
335 while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
336 precision = uj;
337 }
338 }
339 /* parse 'h', 'l' and 'll' length modifiers */
340 if (*p == 'h' || *p == 'l') {
341 length_modifier = *p; p++;
342 if (length_modifier == 'l' && *p == 'l') { /* double l = long long */
343 #ifdef SNPRINTF_LONGLONG_SUPPORT
344 length_modifier = '2'; /* double l encoded as '2' */
345 #else
346 length_modifier = 'l'; /* treat it as a single 'l' */
347 #endif
348 p++;
349 }
350 }
351 fmt_spec = *p;
352 /* common synonyms: */
353 switch (fmt_spec) {
354 case 'i': fmt_spec = 'd'; break;
355 case 'D': fmt_spec = 'd'; length_modifier = 'l'; break;
356 case 'U': fmt_spec = 'u'; length_modifier = 'l'; break;
357 case 'O': fmt_spec = 'o'; length_modifier = 'l'; break;
358 default: break;
359 }
360 /* get parameter value, do initial processing */
361 switch (fmt_spec) {
362 case '%': /* % behaves similar to 's' regarding flags and field widths */
363 case 'c': /* c behaves similar to 's' regarding flags and field widths */
364 case 's':
365 length_modifier = '\0'; /* wint_t and wchar_t not supported */
366 /* the result of zero padding flag with non-numeric conversion specifier*/
367 /* is undefined. Solaris and HPUX 10 does zero padding in this case, */
368 /* Digital Unix and Linux does not. */
369 zero_padding = 0; /* turn zero padding off for string conversions */
370 str_arg_l = 1;
371 switch (fmt_spec) {
372 case '%':
373 str_arg = p; break;
374 case 'c': {
375 int j = va_arg(ap, int);
376 uchar_arg = (unsigned char) j; /* standard demands unsigned char */
377 str_arg = (const char *) &uchar_arg;
378 break;
379 }
380 case 's':
381 str_arg = va_arg(ap, const char *);
382 if (!str_arg) str_arg_l = 0;
383 /* make sure not to address string beyond the specified precision !!! */
384 else if (!precision_specified) str_arg_l = strlen(str_arg);
385 /* truncate string if necessary as requested by precision */
386 else if (precision == 0) str_arg_l = 0;
387 else {
388 /* memchr on HP does not like n > 2^31 !!! */
389 const char *q = (const char*) memchr(str_arg, '\0',
390 precision <= 0x7fffffff ? precision : 0x7fffffff);
391 str_arg_l = !q ? precision : (q-str_arg);
392 }
393 break;
394 default: break;
395 }
396 break;
397 case 'd': case 'u': case 'o': case 'x': case 'X': case 'p': {
398 /* NOTE: the u, o, x, X and p conversion specifiers imply
399 the value is unsigned; d implies a signed value */
400
401 int arg_sign = 0;
402 /* 0 if numeric argument is zero (or if pointer is NULL for 'p'),
403 +1 if greater than zero (or nonzero for unsigned arguments),
404 -1 if negative (unsigned argument is never negative) */
405
406 int int_arg = 0; unsigned int uint_arg = 0;
407 /* only defined for length modifier h, or for no length modifiers */
408
409 long int long_arg = 0; unsigned long int ulong_arg = 0;
410 /* only defined for length modifier l */
411
412 void *ptr_arg = NULL;
413 /* pointer argument value -only defined for p conversion */
414
415 #ifdef SNPRINTF_LONGLONG_SUPPORT
416 long long int long_long_arg = 0;
417 unsigned long long int ulong_long_arg = 0;
418 /* only defined for length modifier ll */
419 #endif
420 if (fmt_spec == 'p') {
421 /* HPUX 10: An l, h, ll or L before any other conversion character
422 * (other than d, i, u, o, x, or X) is ignored.
423 * Digital Unix:
424 * not specified, but seems to behave as HPUX does.
425 * Solaris: If an h, l, or L appears before any other conversion
426 * specifier (other than d, i, u, o, x, or X), the behavior
427 * is undefined. (Actually %hp converts only 16-bits of address
428 * and %llp treats address as 64-bit data which is incompatible
429 * with (void *) argument on a 32-bit system).
430 */
431 length_modifier = '\0';
432 ptr_arg = va_arg(ap, void *);
433 if (ptr_arg != NULL) arg_sign = 1;
434 } else if (fmt_spec == 'd') { /* signed */
435 switch (length_modifier) {
436 case '\0':
437 case 'h':
438 /* It is non-portable to specify a second argument of char or short
439 * to va_arg, because arguments seen by the called function
440 * are not char or short. C converts char and short arguments
441 * to int before passing them to a function.
442 */
443 int_arg = va_arg(ap, int);
444 if (int_arg > 0) arg_sign = 1;
445 else if (int_arg < 0) arg_sign = -1;
446 break;
447 case 'l':
448 long_arg = va_arg(ap, long int);
449 if (long_arg > 0) arg_sign = 1;
450 else if (long_arg < 0) arg_sign = -1;
451 break;
452 #ifdef SNPRINTF_LONGLONG_SUPPORT
453 case '2':
454 long_long_arg = va_arg(ap, long long int);
455 if (long_long_arg > 0) arg_sign = 1;
456 else if (long_long_arg < 0) arg_sign = -1;
457 break;
458 #endif
459 }
460 } else { /* unsigned */
461 switch (length_modifier) {
462 case '\0':
463 case 'h':
464 uint_arg = va_arg(ap, unsigned int);
465 if (uint_arg) arg_sign = 1;
466 break;
467 case 'l':
468 ulong_arg = va_arg(ap, unsigned long int);
469 if (ulong_arg) arg_sign = 1;
470 break;
471 #ifdef SNPRINTF_LONGLONG_SUPPORT
472 case '2':
473 ulong_long_arg = va_arg(ap, unsigned long long int);
474 if (ulong_long_arg) arg_sign = 1;
475 break;
476 #endif
477 }
478 }
479 str_arg = tmp; str_arg_l = 0;
480 /* NOTE:
481 * For d, i, u, o, x, and X conversions, if precision is specified,
482 * the '0' flag should be ignored. This is so with Solaris 2.6,
483 * Digital UNIX 4.0, HPUX 10, Linux, FreeBSD, NetBSD; but not with Perl.
484 */
485 if (precision_specified) zero_padding = 0;
486 if (fmt_spec == 'd') {
487 if (force_sign && arg_sign >= 0)
488 tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
489 /* leave negative numbers for sprintf to handle,
490 to avoid handling tricky cases like (short int)(-32768) */
491 } else if (alternate_form) {
492 if (arg_sign != 0 && (fmt_spec == 'x' || fmt_spec == 'X') )
493 { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = fmt_spec; }
494 /* alternate form should have no effect for p conversion, but ... */
495 }
496 zero_padding_insertion_ind = str_arg_l;
497 if (!precision_specified) precision = 1; /* default precision is 1 */
498 if (precision == 0 && arg_sign == 0
499 ) {
500 /* converted to null string */
501 /* When zero value is formatted with an explicit precision 0,
502 the resulting formatted string is empty (d, i, u, o, x, X, p). */
503 } else {
504 char f[5]; int f_l = 0;
505 f[f_l++] = '%'; /* construct a simple format string for sprintf */
506 if (!length_modifier) { }
507 else if (length_modifier=='2') { f[f_l++] = 'l'; f[f_l++] = 'l'; }
508 else f[f_l++] = length_modifier;
509 f[f_l++] = fmt_spec; f[f_l++] = '\0';
510 if (fmt_spec == 'p') str_arg_l += sprintf(tmp+str_arg_l, f, ptr_arg);
511 else if (fmt_spec == 'd') { /* signed */
512 switch (length_modifier) {
513 case '\0':
514 case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, int_arg); break;
515 case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, long_arg); break;
516 #ifdef SNPRINTF_LONGLONG_SUPPORT
517 case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,long_long_arg); break;
518 #endif
519 }
520 } else { /* unsigned */
521 switch (length_modifier) {
522 case '\0':
523 case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, uint_arg); break;
524 case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, ulong_arg); break;
525 #ifdef SNPRINTF_LONGLONG_SUPPORT
526 case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,ulong_long_arg);break;
527 #endif
528 }
529 }
530 /* include the optional minus sign and possible "0x"
531 in the region before the zero padding insertion point */
532 if (zero_padding_insertion_ind < str_arg_l &&
533 tmp[zero_padding_insertion_ind] == '-') {
534 zero_padding_insertion_ind++;
535 }
536 if (zero_padding_insertion_ind+1 < str_arg_l &&
537 tmp[zero_padding_insertion_ind] == '0' &&
538 (tmp[zero_padding_insertion_ind+1] == 'x' ||
539 tmp[zero_padding_insertion_ind+1] == 'X') ) {
540 zero_padding_insertion_ind += 2;
541 }
542 }
543 { size_t num_of_digits = str_arg_l - zero_padding_insertion_ind;
544 if (alternate_form && fmt_spec == 'o'
545 /* unless zero is already the first character */
546 && !(zero_padding_insertion_ind < str_arg_l
547 && tmp[zero_padding_insertion_ind] == '0')
548 ) { /* assure leading zero for alternate-form octal numbers */
549 if (!precision_specified || precision < num_of_digits+1) {
550 /* precision is increased to force the first character to be zero,
551 except if a zero value is formatted with an explicit precision
552 of zero */
553 precision = num_of_digits+1; precision_specified = 1;
554 }
555 }
556 /* zero padding to specified precision? */
557 if (num_of_digits < precision)
558 number_of_zeros_to_pad = precision - num_of_digits;
559 }
560 /* zero padding to specified minimal field width? */
561 if (!justify_left && zero_padding) {
562 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
563 if (n > 0) number_of_zeros_to_pad += n;
564 }
565 break;
566 }
567 default: /* unrecognized conversion specifier, keep format string as-is*/
568 zero_padding = 0; /* turn zero padding off for non-numeric convers. */
569 justify_left = 1; min_field_width = 0; /* reset flags */
570 /* discard the unrecognized conversion, just keep *
571 * the unrecognized conversion character */
572 str_arg = p; str_arg_l = 0;
573 if (*p) str_arg_l++; /* include invalid conversion specifier unchanged
574 if not at end-of-string */
575 break;
576 }
577 if (*p) p++; /* step over the just processed conversion specifier */
578 /* insert padding to the left as requested by min_field_width;
579 this does not include the zero padding in case of numerical conversions*/
580 if (!justify_left) { /* left padding with blank or zero */
581 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
582 if (n > 0) {
583 if (str_l < str_m) {
584 size_t avail = str_m-str_l;
585 fast_memset(str+str_l, (zero_padding?'0':' '), (n>avail?avail:n));
586 }
587 str_l += n;
588 }
589 }
590 /* zero padding as requested by the precision or by the minimal field width
591 * for numeric conversions required? */
592 if (number_of_zeros_to_pad <= 0) {
593 /* will not copy first part of numeric right now, *
594 * force it to be copied later in its entirety */
595 zero_padding_insertion_ind = 0;
596 } else {
597 /* insert first part of numerics (sign or '0x') before zero padding */
598 int n = zero_padding_insertion_ind;
599 if (n > 0) {
600 if (str_l < str_m) {
601 size_t avail = str_m-str_l;
602 fast_memcpy(str+str_l, str_arg, (n>avail?avail:n));
603 }
604 str_l += n;
605 }
606 /* insert zero padding as requested by the precision or min field width */
607 n = number_of_zeros_to_pad;
608 if (n > 0) {
609 if (str_l < str_m) {
610 size_t avail = str_m-str_l;
611 fast_memset(str+str_l, '0', (n>avail?avail:n));
612 }
613 str_l += n;
614 }
615 }
616 /* insert formatted string
617 * (or as-is conversion specifier for unknown conversions) */
618 { int n = str_arg_l - zero_padding_insertion_ind;
619 if (n > 0) {
620 if (str_l < str_m) {
621 size_t avail = str_m-str_l;
622 fast_memcpy(str+str_l, str_arg+zero_padding_insertion_ind,
623 (n>avail?avail:n));
624 }
625 str_l += n;
626 }
627 }
628 /* insert right padding */
629 if (justify_left) { /* right blank padding to the field width */
630 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
631 if (n > 0) {
632 if (str_l < str_m) {
633 size_t avail = str_m-str_l;
634 fast_memset(str+str_l, ' ', (n>avail?avail:n));
635 }
636 str_l += n;
637 }
638 }
639 }
640 }
641 if (str_m > 0) { /* make sure the string is null-terminated
642 even at the expense of overwriting the last character
643 (shouldn't happen, but just in case) */
644 str[str_l <= str_m-1 ? str_l : str_m-1] = '\0';
645 }
646 /* Return the number of characters formatted (excluding trailing null
647 * character), that is, the number of characters that would have been
648 * written to the buffer if it were large enough.
649 *
650 * The value of str_l should be returned, but str_l is of unsigned type
651 * size_t, and snprintf is int, possibly leading to an undetected
652 * integer overflow, resulting in a negative return value, which is illegal.
653 * Both XSH5 and ISO C99 (at least the draft) are silent on this issue.
654 * Should errno be set to EOVERFLOW and EOF returned in this case???
655 */
656 return (int) str_l;
657 }
658
snprintf(char * text,size_t maxlen,const char * fmt,...)659 int snprintf(char *text, size_t maxlen, const char *fmt, ...) {
660 va_list ap;
661 int retval;
662
663 va_start(ap, fmt);
664 retval = vsnprintf(text, maxlen, fmt, ap);
665 va_end(ap);
666
667 return retval;
668 }
669