3 * snprintf.c - a portable implementation of snprintf
6 * Mark Martinec <mark.martinec@ijs.si>, April 1999.
8 * Copyright 1999, Mark Martinec. All rights reserved.
10 * TERMS AND CONDITIONS
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the "Frontier Artistic License" which comes
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty
17 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
18 * See the Frontier Artistic License for more details.
20 * You should have received a copy of the Frontier Artistic License
21 * with this Kit in the file named LICENSE.txt .
22 * If not, I'll be glad to provide one.
25 * - careful adherence to specs regarding flags, field width and precision;
26 * - good performance for large string handling (large format, large
27 * argument or large paddings). Performance is similar to system's sprintf
28 * and in several cases significantly better (make sure you compile with
29 * optimizations turned on, tell the compiler the code is strict ANSI
30 * if necessary to give it more freedom for optimizations);
31 * - return value semantics per ISO/IEC 9899:1999 ("ISO C99");
32 * - written in standard ISO/ANSI C - requires an ANSI C compiler.
34 * SUPPORTED CONVERSION SPECIFIERS AND DATA TYPES
36 * This snprintf only supports the following conversion specifiers:
37 * s, c, d, u, o, x, X, p (and synonyms: i, D, U, O - see below)
38 * with flags: '-', '+', ' ', '0' and '#'.
39 * An asterisk is supported for field width as well as precision.
41 * Length modifiers 'h' (short int), 'l' (long int),
42 * and 'll' (long long int) are supported.
44 * If macro SNPRINTF_LONGLONG_SUPPORT is not defined (default) the
45 * length modifier 'll' is recognized but treated the same as 'l',
46 * which may cause argument value truncation! Defining
47 * SNPRINTF_LONGLONG_SUPPORT requires that your system's sprintf also
48 * handles length modifier 'll'. long long int is a language extension
49 * which may not be portable.
51 * Conversion of numeric data (conversion specifiers d, u, o, x, X, p)
52 * with length modifiers (none or h, l, ll) is left to the system routine
53 * sprintf, but all handling of flags, field width and precision as well as
54 * c and s conversions is done very carefully by this portable routine.
55 * If a string precision (truncation) is specified (e.g. %.8s) it is
56 * guaranteed the string beyond the specified precision will not be referenced.
58 * Length modifiers h, l and ll are ignored for c and s conversions (data
59 * types wint_t and wchar_t are not supported).
61 * The following common synonyms for conversion characters are supported:
62 * - i is a synonym for d
63 * - D is a synonym for ld, explicit length modifiers are ignored
64 * - U is a synonym for lu, explicit length modifiers are ignored
65 * - O is a synonym for lo, explicit length modifiers are ignored
66 * The D, O and U conversion characters are nonstandard, they are supported
67 * for backward compatibility only, and should not be used for new code.
69 * The following is specifically NOT supported:
70 * - flag ' (thousands' grouping character) is recognized but ignored
71 * - numeric conversion specifiers: f, e, E, g, G and synonym F,
72 * as well as the new a and A conversion specifiers
73 * - length modifier 'L' (long double) and 'q' (quad - use 'll' instead)
74 * - wide character/string conversions: lc, ls, and nonstandard
76 * - writeback of converted string length: conversion character n
77 * - the n$ specification for direct reference to n-th argument
80 * It is permitted for str_m to be zero, and it is permitted to specify NULL
81 * pointer for resulting string argument if str_m is zero (as per ISO C99).
83 * The return value is the number of characters which would be generated
84 * for the given input, excluding the trailing null. If this value
85 * is greater or equal to str_m, not all characters from the result
86 * have been stored in str, output bytes beyond the (str_m-1) -th character
87 * are discarded. If str_m is greater than zero it is guaranteed
88 * the resulting string will be null-terminated.
90 * NOTE that this matches the ISO C99, OpenBSD, and GNU C library 2.1,
91 * but is different from some older and vendor implementations,
92 * and is also different from XPG, XSH5, SUSv2 specifications.
93 * For historical discussion on changes in the semantics and standards
94 * of snprintf see printf(3) man page in the Linux programmers manual.
96 * Routines asprintf and vasprintf return a pointer (in the ptr argument)
97 * to a buffer sufficiently large to hold the resulting string. This pointer
98 * should be passed to free(3) to release the allocated storage when it is
99 * no longer needed. If sufficient space cannot be allocated, these functions
100 * will return -1 and set ptr to be a NULL pointer. These two routines are a
101 * GNU C library extensions (glibc).
103 * Routines asnprintf and vasnprintf are similar to asprintf and vasprintf,
104 * yet, like snprintf and vsnprintf counterparts, will write at most str_m-1
105 * characters into the allocated output string, the last character in the
106 * allocated buffer then gets the terminating null. If the formatted string
107 * length (the return value) is greater than or equal to the str_m argument,
108 * the resulting string was truncated and some of the formatted characters
109 * were discarded. These routines present a handy way to limit the amount
110 * of allocated memory to some sane value.
113 * http://www.ijs.si/software/snprintf/
116 * 1999-04 V0.9 Mark Martinec
117 * - initial version, some modifications after comparing printf
118 * man pages for Digital Unix 4.0, Solaris 2.6 and HPUX 10,
119 * and checking how Perl handles sprintf (differently!);
120 * 1999-04-09 V1.0 Mark Martinec <mark.martinec@ijs.si>
121 * - added main test program, fixed remaining inconsistencies,
122 * added optional (long long int) support;
123 * 1999-04-12 V1.1 Mark Martinec <mark.martinec@ijs.si>
124 * - support the 'p' conversion (pointer to void);
125 * - if a string precision is specified
126 * make sure the string beyond the specified precision
127 * will not be referenced (e.g. by strlen);
128 * 1999-04-13 V1.2 Mark Martinec <mark.martinec@ijs.si>
129 * - support synonyms %D=%ld, %U=%lu, %O=%lo;
130 * - speed up the case of long format string with few conversions;
131 * 1999-06-30 V1.3 Mark Martinec <mark.martinec@ijs.si>
132 * - fixed runaway loop (eventually crashing when str_l wraps
133 * beyond 2^31) while copying format string without
134 * conversion specifiers to a buffer that is too short
135 * (thanks to Edwin Young <edwiny@autonomy.com> for
136 * spotting the problem);
137 * - added macros PORTABLE_SNPRINTF_VERSION_(MAJOR|MINOR)
139 * 2000-02-14 V2.0 (never released) Mark Martinec <mark.martinec@ijs.si>
140 * - relaxed license terms: The Artistic License now applies.
141 * You may still apply the GNU GENERAL PUBLIC LICENSE
142 * as was distributed with previous versions, if you prefer;
143 * - changed REVISION HISTORY dates to use ISO 8601 date format;
144 * - added vsnprintf (patch also independently proposed by
145 * Caolan McNamara 2000-05-04, and Keith M Willenson 2000-06-01)
146 * 2000-06-27 V2.1 Mark Martinec <mark.martinec@ijs.si>
147 * - removed POSIX check for str_m<1; value 0 for str_m is
148 * allowed by ISO C99 (and GNU C library 2.1) - (pointed out
149 * on 2000-05-04 by Caolan McNamara, caolan@ csn dot ul dot ie).
150 * Besides relaxed license this change in standards adherence
151 * is the main reason to bump up the major version number;
152 * - added nonstandard routines asnprintf, vasnprintf, asprintf,
153 * vasprintf that dynamically allocate storage for the
154 * resulting string; these routines are not compiled by default,
155 * see comments where NEED_V?ASN?PRINTF macros are defined;
156 * - autoconf contributed by Caolan McNamara
157 * 2000-10-06 V2.2 Mark Martinec <mark.martinec@ijs.si>
158 * - BUG FIX: the %c conversion used a temporary variable
159 * that was no longer in scope when referenced,
160 * possibly causing incorrect resulting character;
161 * - BUG FIX: make precision and minimal field width unsigned
162 * to handle huge values (2^31 <= n < 2^32) correctly;
163 * also be more careful in the use of signed/unsigned/size_t
164 * internal variables - probably more careful than many
165 * vendor implementations, but there may still be a case
166 * where huge values of str_m, precision or minimal field
167 * could cause incorrect behaviour;
168 * - use separate variables for signed/unsigned arguments,
169 * and for short/int, long, and long long argument lengths
170 * to avoid possible incompatibilities on certain
171 * computer architectures. Also use separate variable
172 * arg_sign to hold sign of a numeric argument,
173 * to make code more transparent;
174 * - some fiddling with zero padding and "0x" to make it
176 * - systematically use macros fast_memcpy and fast_memset
177 * instead of case-by-case hand optimization; determine some
178 * breakeven string lengths for different architectures;
179 * - terminology change: 'format' -> 'conversion specifier',
180 * 'C9x' -> 'ISO/IEC 9899:1999 ("ISO C99")',
181 * 'alternative form' -> 'alternate form',
182 * 'data type modifier' -> 'length modifier';
183 * - several comments rephrased and new ones added;
184 * - make compiler not complain about 'credits' defined but
189 /* Define HAVE_SNPRINTF if your system already has snprintf and vsnprintf.
191 * If HAVE_SNPRINTF is defined this module will not produce code for
192 * snprintf and vsnprintf, unless PREFER_PORTABLE_SNPRINTF is defined as well,
193 * causing this portable version of snprintf to be called portable_snprintf
194 * (and portable_vsnprintf).
196 /* #define HAVE_SNPRINTF */
198 /* Define PREFER_PORTABLE_SNPRINTF if your system does have snprintf and
199 * vsnprintf but you would prefer to use the portable routine(s) instead.
200 * In this case the portable routine is declared as portable_snprintf
201 * (and portable_vsnprintf) and a macro 'snprintf' (and 'vsnprintf')
202 * is defined to expand to 'portable_v?snprintf' - see file snprintf.h .
203 * Defining this macro is only useful if HAVE_SNPRINTF is also defined,
204 * but does does no harm if defined nevertheless.
206 /* #define PREFER_PORTABLE_SNPRINTF */
208 /* Define SNPRINTF_LONGLONG_SUPPORT if you want to support
209 * data type (long long int) and length modifier 'll' (e.g. %lld).
210 * If undefined, 'll' is recognized but treated as a single 'l'.
212 * If the system's sprintf does not handle 'll'
213 * the SNPRINTF_LONGLONG_SUPPORT must not be defined!
215 * This is off by default as (long long int) is a language extension.
217 /* #define SNPRINTF_LONGLONG_SUPPORT */
219 /* Define NEED_SNPRINTF_ONLY if you only need snprintf, and not vsnprintf.
220 * If NEED_SNPRINTF_ONLY is defined, the snprintf will be defined directly,
221 * otherwise both snprintf and vsnprintf routines will be defined
222 * and snprintf will be a simple wrapper around vsnprintf, at the expense
223 * of an extra procedure call.
225 /* #define NEED_SNPRINTF_ONLY */
227 /* Define NEED_V?ASN?PRINTF macros if you need library extension
228 * routines asprintf, vasprintf, asnprintf, vasnprintf respectively,
229 * and your system library does not provide them. They are all small
230 * wrapper routines around portable_vsnprintf. Defining any of the four
231 * NEED_V?ASN?PRINTF macros automatically turns off NEED_SNPRINTF_ONLY
232 * and turns on PREFER_PORTABLE_SNPRINTF.
234 * Watch for name conflicts with the system library if these routines
235 * are already present there.
237 * NOTE: vasprintf and vasnprintf routines need va_copy() from stdarg.h, as
238 * specified by C99, to be able to traverse the same list of arguments twice.
239 * I don't know of any other standard and portable way of achieving the same.
240 * With some versions of gcc you may use __va_copy(). You might even get away
241 * with "ap2 = ap", in this case you must not call va_end(ap2) !
242 * #define va_copy(ap2,ap) ap2 = ap
244 /* #define NEED_ASPRINTF */
245 /* #define NEED_ASNPRINTF */
246 /* #define NEED_VASPRINTF */
247 /* #define NEED_VASNPRINTF */
250 /* Define the following macros if desired:
251 * SOLARIS_COMPATIBLE, SOLARIS_BUG_COMPATIBLE,
252 * HPUX_COMPATIBLE, HPUX_BUG_COMPATIBLE, LINUX_COMPATIBLE,
253 * DIGITAL_UNIX_COMPATIBLE, DIGITAL_UNIX_BUG_COMPATIBLE,
254 * PERL_COMPATIBLE, PERL_BUG_COMPATIBLE,
256 * - For portable applications it is best not to rely on peculiarities
257 * of a given implementation so it may be best not to define any
258 * of the macros that select compatibility and to avoid features
259 * that vary among the systems.
261 * - Selecting compatibility with more than one operating system
262 * is not strictly forbidden but is not recommended.
264 * - 'x'_BUG_COMPATIBLE implies 'x'_COMPATIBLE .
266 * - 'x'_COMPATIBLE refers to (and enables) a behaviour that is
267 * documented in a sprintf man page on a given operating system
268 * and actually adhered to by the system's sprintf (but not on
269 * most other operating systems). It may also refer to and enable
270 * a behaviour that is declared 'undefined' or 'implementation specific'
271 * in the man page but a given implementation behaves predictably
274 * - 'x'_BUG_COMPATIBLE refers to (and enables) a behaviour of system's sprintf
275 * that contradicts the sprintf man page on the same operating system.
277 * - I do not claim that the 'x'_COMPATIBLE and 'x'_BUG_COMPATIBLE
278 * conditionals take into account all idiosyncrasies of a particular
279 * implementation, there may be other incompatibilities.
283 /* ============================================= */
284 /* NO USER SERVICABLE PARTS FOLLOWING THIS POINT */
285 /* ============================================= */
287 #define PORTABLE_SNPRINTF_VERSION_MAJOR 2
288 #define PORTABLE_SNPRINTF_VERSION_MINOR 2
290 #if defined(NEED_ASPRINTF) || defined(NEED_ASNPRINTF) || defined(NEED_VASPRINTF) || defined(NEED_VASNPRINTF)
291 # if defined(NEED_SNPRINTF_ONLY)
292 # undef NEED_SNPRINTF_ONLY
294 # if !defined(PREFER_PORTABLE_SNPRINTF)
295 # define PREFER_PORTABLE_SNPRINTF
299 #if defined(SOLARIS_BUG_COMPATIBLE) && !defined(SOLARIS_COMPATIBLE)
300 #define SOLARIS_COMPATIBLE
303 #if defined(HPUX_BUG_COMPATIBLE) && !defined(HPUX_COMPATIBLE)
304 #define HPUX_COMPATIBLE
307 #if defined(DIGITAL_UNIX_BUG_COMPATIBLE) && !defined(DIGITAL_UNIX_COMPATIBLE)
308 #define DIGITAL_UNIX_COMPATIBLE
311 #if defined(PERL_BUG_COMPATIBLE) && !defined(PERL_COMPATIBLE)
312 #define PERL_COMPATIBLE
315 #if defined(LINUX_BUG_COMPATIBLE) && !defined(LINUX_COMPATIBLE)
316 #define LINUX_COMPATIBLE
319 #include "portable.h" /* to get a working stdarg.h */
321 #include <sys/types.h>
334 #define isdigit(c) ((c) >= '0' && (c) <= '9')
336 /* For copying strings longer or equal to 'breakeven_point'
337 * it is more efficient to call memcpy() than to do it inline.
338 * The value depends mostly on the processor architecture,
339 * but also on the compiler and its optimization capabilities.
340 * The value is not critical, some small value greater than zero
341 * will be just fine if you don't care to squeeze every drop
342 * of performance out of the code.
344 * Small values favor memcpy, large values favor inline code.
346 #if defined(__alpha__) || defined(__alpha)
347 # define breakeven_point 2 /* AXP (DEC Alpha) - gcc or cc or egcs */
349 #if defined(__i386__) || defined(__i386)
350 # define breakeven_point 12 /* Intel Pentium/Linux - gcc 2.96 */
353 # define breakeven_point 10 /* HP-PA - gcc */
355 #if defined(__sparc__) || defined(__sparc)
356 # define breakeven_point 33 /* Sun Sparc 5 - gcc 2.8.1 */
359 /* some other values of possible interest: */
360 /* #define breakeven_point 8 */ /* VAX 4000 - vaxc */
361 /* #define breakeven_point 19 */ /* VAX 4000 - gcc 2.7.0 */
363 #ifndef breakeven_point
364 # define breakeven_point 6 /* some reasonable one-size-fits-all value */
367 #define fast_memcpy(d,s,n) \
368 { register size_t nn = (size_t)(n); \
369 if (nn >= breakeven_point) memcpy((d), (s), nn); \
370 else if (nn > 0) { /* proc call overhead is worth only for large strings*/\
371 register char *dd; register const char *ss; \
372 for (ss=(s), dd=(d); nn>0; nn--) *dd++ = *ss++; } }
374 #define fast_memset(d,c,n) \
375 { register size_t nn = (size_t)(n); \
376 if (nn >= breakeven_point) memset((d), (int)(c), nn); \
377 else if (nn > 0) { /* proc call overhead is worth only for large strings*/\
378 register char *dd; register const int cc=(int)(c); \
379 for (dd=(d); nn>0; nn--) *dd++ = cc; } }
384 #if defined(NEED_ASPRINTF)
385 int asprintf (char **ptr, const char *fmt, /*args*/ ...);
387 #if defined(NEED_VASPRINTF)
388 int vasprintf (char **ptr, const char *fmt, va_list ap);
391 #if defined(NEED_ASNPRINTF)
392 int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...);
394 #if defined(NEED_VASNPRINTF)
395 int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap);
398 #if defined(HAVE_SNPRINTF)
399 /* declare our portable snprintf routine under name portable_snprintf */
400 /* declare our portable vsnprintf routine under name portable_vsnprintf */
401 # if defined(_MSC_VER) && (_MSC_VER >= 1400)
402 # define portable_snprintf _snprintf
403 # define portable_vsnprintf vsnprintf
405 # define portable_snprintf snprintf
406 # define portable_vsnprintf vsnprintf
409 /* declare our portable routines under names snprintf and vsnprintf */
410 #define portable_snprintf snprintf
411 #if !defined(NEED_SNPRINTF_ONLY)
412 #define portable_vsnprintf vsnprintf
416 #if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF)
417 int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...);
418 #if !defined(NEED_SNPRINTF_ONLY)
419 int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap);
425 static char credits[] = "\n\
426 @(#)snprintf.c, v2.2: Mark Martinec, <mark.martinec@ijs.si>\n\
427 @(#)snprintf.c, v2.2: Copyright 1999, Mark Martinec. Frontier Artistic License applies.\n\
428 @(#)snprintf.c, v2.2: http://www.ijs.si/software/snprintf/\n";
430 static void __foo__(void)
432 printf("%s",credits);
436 #if defined(NEED_ASPRINTF)
437 int asprintf(char **ptr, const char *fmt, /*args*/ ...) {
443 va_start(ap, fmt); /* measure the required size */
444 str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap);
446 assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
447 *ptr = (char *) malloc(str_m = (size_t)str_l + 1);
448 if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
452 str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
454 assert(str_l2 == str_l);
460 #if defined(NEED_VASPRINTF)
461 int vasprintf(char **ptr, const char *fmt, va_list ap) {
467 va_copy(ap2, ap); /* don't consume the original ap, we'll need it again */
468 str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/
471 assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
472 *ptr = (char *) malloc(str_m = (size_t)str_l + 1);
473 if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
475 int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
476 assert(str_l2 == str_l);
482 #if defined(NEED_ASNPRINTF)
483 int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...) {
488 va_start(ap, fmt); /* measure the required size */
489 str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap);
491 assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
492 if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1; /* truncate */
493 /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */
494 if (str_m == 0) { /* not interested in resulting string, just return size */
496 *ptr = (char *) malloc(str_m);
497 if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
501 str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
503 assert(str_l2 == str_l);
510 #if defined(NEED_VASNPRINTF)
511 int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap) {
516 va_copy(ap2, ap); /* don't consume the original ap, we'll need it again */
517 str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/
520 assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
521 if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1; /* truncate */
522 /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */
523 if (str_m == 0) { /* not interested in resulting string, just return size */
525 *ptr = (char *) malloc(str_m);
526 if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
528 int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
529 assert(str_l2 == str_l);
537 * If the system does have snprintf and the portable routine is not
538 * specifically required, this module produces no code for snprintf/vsnprintf.
540 #if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF)
542 #if !defined(NEED_SNPRINTF_ONLY)
543 int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
548 str_l = portable_vsnprintf(str, str_m, fmt, ap);
554 #if defined(NEED_SNPRINTF_ONLY)
555 int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
557 int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap) {
560 #if defined(NEED_SNPRINTF_ONLY)
566 /* In contrast with POSIX, the ISO C99 now says
567 * that str can be NULL and str_m can be 0.
568 * This is more useful than the old: if (str_m < 1) return -1; */
570 #if defined(NEED_SNPRINTF_ONLY)
576 /* if (str_l < str_m) str[str_l++] = *p++; -- this would be sufficient */
577 /* but the following code achieves better performance for cases
578 * where format string is long and contains few conversions */
579 const char *q = strchr(p+1,'%');
580 size_t n = !q ? strlen(p) : (q-p);
582 size_t avail = str_m-str_l;
583 fast_memcpy(str+str_l, p, (n>avail?avail:n));
587 const char *starting_p;
588 size_t min_field_width = 0, precision = 0;
589 int zero_padding = 0, precision_specified = 0, justify_left = 0;
590 int alternate_form = 0, force_sign = 0;
591 int space_for_positive = 1; /* If both the ' ' and '+' flags appear,
592 the ' ' flag should be ignored. */
593 char length_modifier = '\0'; /* allowed values: \0, h, l, L */
594 char tmp[32];/* temporary buffer for simple numeric->string conversion */
596 const char *str_arg; /* string address in case of string argument */
597 size_t str_arg_l; /* natural field width of arg without padding
599 unsigned char uchar_arg;
600 /* unsigned char argument value - only defined for c conversion.
601 N.B. standard explicitly states the char argument for
602 the c conversion is unsigned */
604 size_t number_of_zeros_to_pad = 0;
605 /* number of zeros to be inserted for numeric conversions
606 as required by the precision or minimal field width */
608 size_t zero_padding_insertion_ind = 0;
609 /* index into tmp where zero padding is to be inserted */
611 char fmt_spec = '\0';
612 /* current conversion specifier character */
614 str_arg = credits;/* just to make compiler happy (defined but not used)*/
616 starting_p = p; p++; /* skip '%' */
618 while (*p == '0' || *p == '-' || *p == '+' ||
619 *p == ' ' || *p == '#' || *p == '\'') {
621 case '0': zero_padding = 1; break;
622 case '-': justify_left = 1; break;
623 case '+': force_sign = 1; space_for_positive = 0; break;
624 case ' ': force_sign = 1;
625 /* If both the ' ' and '+' flags appear, the ' ' flag should be ignored */
626 #ifdef PERL_COMPATIBLE
627 /* ... but in Perl the last of ' ' and '+' applies */
628 space_for_positive = 1;
631 case '#': alternate_form = 1; break;
636 /* If the '0' and '-' flags both appear, the '0' flag should be ignored. */
638 /* parse field width */
641 p++; j = va_arg(ap, int);
642 if (j >= 0) min_field_width = j;
643 else { min_field_width = -j; justify_left = 1; }
644 } else if (isdigit((int)(*p))) {
645 /* size_t could be wider than unsigned int;
646 make sure we treat argument like common implementations do */
647 unsigned int uj = *p++ - '0';
648 while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
649 min_field_width = uj;
651 /* parse precision */
653 p++; precision_specified = 1;
655 int j = va_arg(ap, int);
657 if (j >= 0) precision = j;
659 precision_specified = 0; precision = 0;
661 * Solaris 2.6 man page claims that in this case the precision
662 * should be set to 0. Digital Unix 4.0, HPUX 10 and BSD man page
663 * claim that this case should be treated as unspecified precision,
664 * which is what we do here.
667 } else if (isdigit((int)(*p))) {
668 /* size_t could be wider than unsigned int;
669 make sure we treat argument like common implementations do */
670 unsigned int uj = *p++ - '0';
671 while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
675 /* parse 'h', 'l' and 'll' length modifiers */
676 if (*p == 'h' || *p == 'l') {
677 length_modifier = *p; p++;
678 if (length_modifier == 'l' && *p == 'l') { /* double l = long long */
679 #ifdef SNPRINTF_LONGLONG_SUPPORT
680 length_modifier = '2'; /* double l encoded as '2' */
682 length_modifier = 'l'; /* treat it as a single 'l' */
688 /* common synonyms: */
690 case 'i': fmt_spec = 'd'; break;
691 case 'D': fmt_spec = 'd'; length_modifier = 'l'; break;
692 case 'U': fmt_spec = 'u'; length_modifier = 'l'; break;
693 case 'O': fmt_spec = 'o'; length_modifier = 'l'; break;
696 /* get parameter value, do initial processing */
698 case '%': /* % behaves similar to 's' regarding flags and field widths */
699 case 'c': /* c behaves similar to 's' regarding flags and field widths */
701 length_modifier = '\0'; /* wint_t and wchar_t not supported */
702 /* the result of zero padding flag with non-numeric conversion specifier*/
703 /* is undefined. Solaris and HPUX 10 does zero padding in this case, */
704 /* Digital Unix and Linux does not. */
705 #if !defined(SOLARIS_COMPATIBLE) && !defined(HPUX_COMPATIBLE)
706 zero_padding = 0; /* turn zero padding off for string conversions */
713 int j = va_arg(ap, int);
714 uchar_arg = (unsigned char) j; /* standard demands unsigned char */
715 str_arg = (const char *) &uchar_arg;
719 str_arg = va_arg(ap, const char *);
720 if (!str_arg) str_arg_l = 0;
721 /* make sure not to address string beyond the specified precision !!! */
722 else if (!precision_specified) str_arg_l = strlen(str_arg);
723 /* truncate string if necessary as requested by precision */
724 else if (precision == 0) str_arg_l = 0;
726 /* memchr on HP does not like n > 2^31 !!! */
727 char *q = (char *) memchr(str_arg, '\0',
728 precision <= 0x7fffffff ? precision : 0x7fffffff);
729 str_arg_l = !q ? precision : (q-str_arg);
735 case 'd': case 'u': case 'o': case 'x': case 'X': case 'p': {
736 /* NOTE: the u, o, x, X and p conversion specifiers imply
737 the value is unsigned; d implies a signed value */
740 /* 0 if numeric argument is zero (or if pointer is NULL for 'p'),
741 +1 if greater than zero (or nonzero for unsigned arguments),
742 -1 if negative (unsigned argument is never negative) */
744 int int_arg = 0; unsigned int uint_arg = 0;
745 /* only defined for length modifier h, or for no length modifiers */
747 long int long_arg = 0; unsigned long int ulong_arg = 0;
748 /* only defined for length modifier l */
750 void *ptr_arg = NULL;
751 /* pointer argument value -only defined for p conversion */
753 #ifdef SNPRINTF_LONGLONG_SUPPORT
754 long long int long_long_arg = 0;
755 unsigned long long int ulong_long_arg = 0;
756 /* only defined for length modifier ll */
758 if (fmt_spec == 'p') {
759 /* HPUX 10: An l, h, ll or L before any other conversion character
760 * (other than d, i, u, o, x, or X) is ignored.
762 * not specified, but seems to behave as HPUX does.
763 * Solaris: If an h, l, or L appears before any other conversion
764 * specifier (other than d, i, u, o, x, or X), the behavior
765 * is undefined. (Actually %hp converts only 16-bits of address
766 * and %llp treats address as 64-bit data which is incompatible
767 * with (void *) argument on a 32-bit system).
769 #ifdef SOLARIS_COMPATIBLE
770 # ifdef SOLARIS_BUG_COMPATIBLE
771 /* keep length modifiers even if it represents 'll' */
773 if (length_modifier == '2') length_modifier = '\0';
776 length_modifier = '\0';
778 ptr_arg = va_arg(ap, void *);
779 if (ptr_arg != NULL) arg_sign = 1;
780 } else if (fmt_spec == 'd') { /* signed */
781 switch (length_modifier) {
784 /* It is non-portable to specify a second argument of char or short
785 * to va_arg, because arguments seen by the called function
786 * are not char or short. C converts char and short arguments
787 * to int before passing them to a function.
789 int_arg = va_arg(ap, int);
790 if (int_arg > 0) arg_sign = 1;
791 else if (int_arg < 0) arg_sign = -1;
794 long_arg = va_arg(ap, long int);
795 if (long_arg > 0) arg_sign = 1;
796 else if (long_arg < 0) arg_sign = -1;
798 #ifdef SNPRINTF_LONGLONG_SUPPORT
800 long_long_arg = va_arg(ap, long long int);
801 if (long_long_arg > 0) arg_sign = 1;
802 else if (long_long_arg < 0) arg_sign = -1;
806 } else { /* unsigned */
807 switch (length_modifier) {
810 uint_arg = va_arg(ap, unsigned int);
811 if (uint_arg) arg_sign = 1;
814 ulong_arg = va_arg(ap, unsigned long int);
815 if (ulong_arg) arg_sign = 1;
817 #ifdef SNPRINTF_LONGLONG_SUPPORT
819 ulong_long_arg = va_arg(ap, unsigned long long int);
820 if (ulong_long_arg) arg_sign = 1;
825 str_arg = tmp; str_arg_l = 0;
827 * For d, i, u, o, x, and X conversions, if precision is specified,
828 * the '0' flag should be ignored. This is so with Solaris 2.6,
829 * Digital UNIX 4.0, HPUX 10, Linux, FreeBSD, NetBSD; but not with Perl.
831 #ifndef PERL_COMPATIBLE
832 if (precision_specified) zero_padding = 0;
834 if (fmt_spec == 'd') {
835 if (force_sign && arg_sign >= 0)
836 tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
837 /* leave negative numbers for sprintf to handle,
838 to avoid handling tricky cases like (short int)(-32768) */
839 #ifdef LINUX_COMPATIBLE
840 } else if (fmt_spec == 'p' && force_sign && arg_sign > 0) {
841 tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
843 } else if (alternate_form) {
844 if (arg_sign != 0 && (fmt_spec == 'x' || fmt_spec == 'X') )
845 { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = fmt_spec; }
846 /* alternate form should have no effect for p conversion, but ... */
847 #ifdef HPUX_COMPATIBLE
848 else if (fmt_spec == 'p'
849 /* HPUX 10: for an alternate form of p conversion,
850 * a nonzero result is prefixed by 0x. */
851 #ifndef HPUX_BUG_COMPATIBLE
852 /* Actually it uses 0x prefix even for a zero value. */
855 ) { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = 'x'; }
858 zero_padding_insertion_ind = str_arg_l;
859 if (!precision_specified) precision = 1; /* default precision is 1 */
860 if (precision == 0 && arg_sign == 0
861 #if defined(HPUX_BUG_COMPATIBLE) || defined(LINUX_COMPATIBLE)
863 /* HPUX 10 man page claims: With conversion character p the result of
864 * converting a zero value with a precision of zero is a null string.
865 * Actually HP returns all zeroes, and Linux returns "(nil)". */
868 /* converted to null string */
869 /* When zero value is formatted with an explicit precision 0,
870 the resulting formatted string is empty (d, i, u, o, x, X, p). */
872 char f[5]; int f_l = 0;
873 f[f_l++] = '%'; /* construct a simple format string for sprintf */
874 if (!length_modifier) { }
875 else if (length_modifier=='2') { f[f_l++] = 'l'; f[f_l++] = 'l'; }
876 else f[f_l++] = length_modifier;
877 f[f_l++] = fmt_spec; f[f_l++] = '\0';
878 if (fmt_spec == 'p') str_arg_l += sprintf(tmp+str_arg_l, f, ptr_arg);
879 else if (fmt_spec == 'd') { /* signed */
880 switch (length_modifier) {
882 case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, int_arg); break;
883 case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, long_arg); break;
884 #ifdef SNPRINTF_LONGLONG_SUPPORT
885 case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,long_long_arg); break;
888 } else { /* unsigned */
889 switch (length_modifier) {
891 case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, uint_arg); break;
892 case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, ulong_arg); break;
893 #ifdef SNPRINTF_LONGLONG_SUPPORT
894 case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,ulong_long_arg);break;
898 /* include the optional minus sign and possible "0x"
899 in the region before the zero padding insertion point */
900 if (zero_padding_insertion_ind < str_arg_l &&
901 tmp[zero_padding_insertion_ind] == '-') {
902 zero_padding_insertion_ind++;
904 if (zero_padding_insertion_ind+1 < str_arg_l &&
905 tmp[zero_padding_insertion_ind] == '0' &&
906 (tmp[zero_padding_insertion_ind+1] == 'x' ||
907 tmp[zero_padding_insertion_ind+1] == 'X') ) {
908 zero_padding_insertion_ind += 2;
911 { size_t num_of_digits = str_arg_l - zero_padding_insertion_ind;
912 if (alternate_form && fmt_spec == 'o'
913 #ifdef HPUX_COMPATIBLE /* ("%#.o",0) -> "" */
916 #ifdef DIGITAL_UNIX_BUG_COMPATIBLE /* ("%#o",0) -> "00" */
918 /* unless zero is already the first character */
919 && !(zero_padding_insertion_ind < str_arg_l
920 && tmp[zero_padding_insertion_ind] == '0')
922 ) { /* assure leading zero for alternate-form octal numbers */
923 if (!precision_specified || precision < num_of_digits+1) {
924 /* precision is increased to force the first character to be zero,
925 except if a zero value is formatted with an explicit precision
927 precision = num_of_digits+1; precision_specified = 1;
930 /* zero padding to specified precision? */
931 if (num_of_digits < precision)
932 number_of_zeros_to_pad = precision - num_of_digits;
934 /* zero padding to specified minimal field width? */
935 if (!justify_left && zero_padding) {
936 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
937 if (n > 0) number_of_zeros_to_pad += n;
941 default: /* unrecognized conversion specifier, keep format string as-is*/
942 zero_padding = 0; /* turn zero padding off for non-numeric convers. */
943 #ifndef DIGITAL_UNIX_COMPATIBLE
944 justify_left = 1; min_field_width = 0; /* reset flags */
946 #if defined(PERL_COMPATIBLE) || defined(LINUX_COMPATIBLE)
947 /* keep the entire format string unchanged */
948 str_arg = starting_p; str_arg_l = p - starting_p;
949 /* well, not exactly so for Linux, which does something inbetween,
950 * and I don't feel an urge to imitate it: "%+++++hy" -> "%+y" */
952 /* discard the unrecognized conversion, just keep *
953 * the unrecognized conversion character */
954 str_arg = p; str_arg_l = 0;
956 if (*p) str_arg_l++; /* include invalid conversion specifier unchanged
957 if not at end-of-string */
960 if (*p) p++; /* step over the just processed conversion specifier */
961 /* insert padding to the left as requested by min_field_width;
962 this does not include the zero padding in case of numerical conversions*/
963 if (!justify_left) { /* left padding with blank or zero */
964 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
967 int avail = str_m-str_l;
968 fast_memset(str+str_l, (zero_padding?'0':' '), (n>avail?avail:n));
973 /* zero padding as requested by the precision or by the minimal field width
974 * for numeric conversions required? */
975 if (number_of_zeros_to_pad <= 0) {
976 /* will not copy first part of numeric right now, *
977 * force it to be copied later in its entirety */
978 zero_padding_insertion_ind = 0;
980 /* insert first part of numerics (sign or '0x') before zero padding */
981 int n = zero_padding_insertion_ind;
984 int avail = str_m-str_l;
985 fast_memcpy(str+str_l, str_arg, (n>avail?avail:n));
989 /* insert zero padding as requested by the precision or min field width */
990 n = number_of_zeros_to_pad;
993 int avail = str_m-str_l;
994 fast_memset(str+str_l, '0', (n>avail?avail:n));
999 /* insert formatted string
1000 * (or as-is conversion specifier for unknown conversions) */
1001 { int n = str_arg_l - zero_padding_insertion_ind;
1003 if (str_l < str_m) {
1004 int avail = str_m-str_l;
1005 fast_memcpy(str+str_l, str_arg+zero_padding_insertion_ind,
1011 /* insert right padding */
1012 if (justify_left) { /* right blank padding to the field width */
1013 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
1015 if (str_l < str_m) {
1016 int avail = str_m-str_l;
1017 fast_memset(str+str_l, ' ', (n>avail?avail:n));
1024 #if defined(NEED_SNPRINTF_ONLY)
1027 if (str_m > 0) { /* make sure the string is null-terminated
1028 even at the expense of overwriting the last character
1029 (shouldn't happen, but just in case) */
1030 str[str_l <= str_m-1 ? str_l : str_m-1] = '\0';
1032 /* Return the number of characters formatted (excluding trailing null
1033 * character), that is, the number of characters that would have been
1034 * written to the buffer if it were large enough.
1036 * The value of str_l should be returned, but str_l is of unsigned type
1037 * size_t, and snprintf is int, possibly leading to an undetected
1038 * integer overflow, resulting in a negative return value, which is illegal.
1039 * Both XSH5 and ISO C99 (at least the draft) are silent on this issue.
1040 * Should errno be set to EOVERFLOW and EOF returned in this case???
1047 /* FIXME: better place */
1048 #include "xbt/sysdep.h"
1050 char *bprintf(const char*fmt, ...) {
1057 len = vasprintf(&res,fmt,ap);