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.
284 /* ============================================= */
285 /* NO USER SERVICABLE PARTS FOLLOWING THIS POINT */
286 /* ============================================= */
288 #define PORTABLE_SNPRINTF_VERSION_MAJOR 2
289 #define PORTABLE_SNPRINTF_VERSION_MINOR 2
291 #if defined(NEED_ASPRINTF) || defined(NEED_ASNPRINTF) || defined(NEED_VASPRINTF) || defined(NEED_VASNPRINTF)
292 # if defined(NEED_SNPRINTF_ONLY)
293 # undef NEED_SNPRINTF_ONLY
295 # if !defined(PREFER_PORTABLE_SNPRINTF)
296 # define PREFER_PORTABLE_SNPRINTF
300 #if defined(SOLARIS_BUG_COMPATIBLE) && !defined(SOLARIS_COMPATIBLE)
301 #define SOLARIS_COMPATIBLE
304 #if defined(HPUX_BUG_COMPATIBLE) && !defined(HPUX_COMPATIBLE)
305 #define HPUX_COMPATIBLE
308 #if defined(DIGITAL_UNIX_BUG_COMPATIBLE) && !defined(DIGITAL_UNIX_COMPATIBLE)
309 #define DIGITAL_UNIX_COMPATIBLE
312 #if defined(PERL_BUG_COMPATIBLE) && !defined(PERL_COMPATIBLE)
313 #define PERL_COMPATIBLE
316 #if defined(LINUX_BUG_COMPATIBLE) && !defined(LINUX_COMPATIBLE)
317 #define LINUX_COMPATIBLE
320 #include <sys/types.h>
326 #include "portable.h" /* to get a working stdarg.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; } }
383 #if defined(NEED_ASPRINTF)
384 int asprintf (char **ptr, const char *fmt, /*args*/ ...);
386 #if defined(NEED_VASPRINTF)
387 int vasprintf (char **ptr, const char *fmt, va_list ap);
389 #if defined(NEED_ASNPRINTF)
390 int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...);
392 #if defined(NEED_VASNPRINTF)
393 int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap);
396 #if defined(HAVE_SNPRINTF)
397 /* declare our portable snprintf routine under name portable_snprintf */
398 /* declare our portable vsnprintf routine under name portable_vsnprintf */
400 /* declare our portable routines under names snprintf and vsnprintf */
401 #define portable_snprintf snprintf
402 #if !defined(NEED_SNPRINTF_ONLY)
403 #define portable_vsnprintf vsnprintf
407 #if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF)
408 int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...);
409 #if !defined(NEED_SNPRINTF_ONLY)
410 int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap);
416 static char credits[] = "\n\
417 @(#)snprintf.c, v2.2: Mark Martinec, <mark.martinec@ijs.si>\n\
418 @(#)snprintf.c, v2.2: Copyright 1999, Mark Martinec. Frontier Artistic License applies.\n\
419 @(#)snprintf.c, v2.2: http://www.ijs.si/software/snprintf/\n";
421 static void __foo__(void)
423 printf("%s",credits);
427 #if defined(NEED_ASPRINTF)
428 int asprintf(char **ptr, const char *fmt, /*args*/ ...) {
434 va_start(ap, fmt); /* measure the required size */
435 str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap);
437 assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
438 *ptr = (char *) malloc(str_m = (size_t)str_l + 1);
439 if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
443 str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
445 assert(str_l2 == str_l);
451 #if defined(NEED_VASPRINTF)
452 int vasprintf(char **ptr, const char *fmt, va_list ap) {
458 va_copy(ap2, ap); /* don't consume the original ap, we'll need it again */
459 str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/
462 assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
463 *ptr = (char *) malloc(str_m = (size_t)str_l + 1);
464 if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
466 int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
467 assert(str_l2 == str_l);
473 #if defined(NEED_ASNPRINTF)
474 int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...) {
479 va_start(ap, fmt); /* measure the required size */
480 str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap);
482 assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
483 if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1; /* truncate */
484 /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */
485 if (str_m == 0) { /* not interested in resulting string, just return size */
487 *ptr = (char *) malloc(str_m);
488 if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
492 str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
494 assert(str_l2 == str_l);
501 #if defined(NEED_VASNPRINTF)
502 int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap) {
507 va_copy(ap2, ap); /* don't consume the original ap, we'll need it again */
508 str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/
511 assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
512 if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1; /* truncate */
513 /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */
514 if (str_m == 0) { /* not interested in resulting string, just return size */
516 *ptr = (char *) malloc(str_m);
517 if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
519 int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
520 assert(str_l2 == str_l);
528 * If the system does have snprintf and the portable routine is not
529 * specifically required, this module produces no code for snprintf/vsnprintf.
531 #if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF)
533 #if !defined(NEED_SNPRINTF_ONLY)
534 int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
539 str_l = portable_vsnprintf(str, str_m, fmt, ap);
545 #if defined(NEED_SNPRINTF_ONLY)
546 int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
548 int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap) {
551 #if defined(NEED_SNPRINTF_ONLY)
557 /* In contrast with POSIX, the ISO C99 now says
558 * that str can be NULL and str_m can be 0.
559 * This is more useful than the old: if (str_m < 1) return -1; */
561 #if defined(NEED_SNPRINTF_ONLY)
567 /* if (str_l < str_m) str[str_l++] = *p++; -- this would be sufficient */
568 /* but the following code achieves better performance for cases
569 * where format string is long and contains few conversions */
570 const char *q = strchr(p+1,'%');
571 size_t n = !q ? strlen(p) : (q-p);
573 size_t avail = str_m-str_l;
574 fast_memcpy(str+str_l, p, (n>avail?avail:n));
578 const char *starting_p;
579 size_t min_field_width = 0, precision = 0;
580 int zero_padding = 0, precision_specified = 0, justify_left = 0;
581 int alternate_form = 0, force_sign = 0;
582 int space_for_positive = 1; /* If both the ' ' and '+' flags appear,
583 the ' ' flag should be ignored. */
584 char length_modifier = '\0'; /* allowed values: \0, h, l, L */
585 char tmp[32];/* temporary buffer for simple numeric->string conversion */
587 const char *str_arg; /* string address in case of string argument */
588 size_t str_arg_l; /* natural field width of arg without padding
590 unsigned char uchar_arg;
591 /* unsigned char argument value - only defined for c conversion.
592 N.B. standard explicitly states the char argument for
593 the c conversion is unsigned */
595 size_t number_of_zeros_to_pad = 0;
596 /* number of zeros to be inserted for numeric conversions
597 as required by the precision or minimal field width */
599 size_t zero_padding_insertion_ind = 0;
600 /* index into tmp where zero padding is to be inserted */
602 char fmt_spec = '\0';
603 /* current conversion specifier character */
605 str_arg = credits;/* just to make compiler happy (defined but not used)*/
607 starting_p = p; p++; /* skip '%' */
609 while (*p == '0' || *p == '-' || *p == '+' ||
610 *p == ' ' || *p == '#' || *p == '\'') {
612 case '0': zero_padding = 1; break;
613 case '-': justify_left = 1; break;
614 case '+': force_sign = 1; space_for_positive = 0; break;
615 case ' ': force_sign = 1;
616 /* If both the ' ' and '+' flags appear, the ' ' flag should be ignored */
617 #ifdef PERL_COMPATIBLE
618 /* ... but in Perl the last of ' ' and '+' applies */
619 space_for_positive = 1;
622 case '#': alternate_form = 1; break;
627 /* If the '0' and '-' flags both appear, the '0' flag should be ignored. */
629 /* parse field width */
632 p++; j = va_arg(ap, int);
633 if (j >= 0) min_field_width = j;
634 else { min_field_width = -j; justify_left = 1; }
635 } else if (isdigit((int)(*p))) {
636 /* size_t could be wider than unsigned int;
637 make sure we treat argument like common implementations do */
638 unsigned int uj = *p++ - '0';
639 while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
640 min_field_width = uj;
642 /* parse precision */
644 p++; precision_specified = 1;
646 int j = va_arg(ap, int);
648 if (j >= 0) precision = j;
650 precision_specified = 0; precision = 0;
652 * Solaris 2.6 man page claims that in this case the precision
653 * should be set to 0. Digital Unix 4.0, HPUX 10 and BSD man page
654 * claim that this case should be treated as unspecified precision,
655 * which is what we do here.
658 } else if (isdigit((int)(*p))) {
659 /* size_t could be wider than unsigned int;
660 make sure we treat argument like common implementations do */
661 unsigned int uj = *p++ - '0';
662 while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
666 /* parse 'h', 'l' and 'll' length modifiers */
667 if (*p == 'h' || *p == 'l') {
668 length_modifier = *p; p++;
669 if (length_modifier == 'l' && *p == 'l') { /* double l = long long */
670 #ifdef SNPRINTF_LONGLONG_SUPPORT
671 length_modifier = '2'; /* double l encoded as '2' */
673 length_modifier = 'l'; /* treat it as a single 'l' */
679 /* common synonyms: */
681 case 'i': fmt_spec = 'd'; break;
682 case 'D': fmt_spec = 'd'; length_modifier = 'l'; break;
683 case 'U': fmt_spec = 'u'; length_modifier = 'l'; break;
684 case 'O': fmt_spec = 'o'; length_modifier = 'l'; break;
687 /* get parameter value, do initial processing */
689 case '%': /* % behaves similar to 's' regarding flags and field widths */
690 case 'c': /* c behaves similar to 's' regarding flags and field widths */
692 length_modifier = '\0'; /* wint_t and wchar_t not supported */
693 /* the result of zero padding flag with non-numeric conversion specifier*/
694 /* is undefined. Solaris and HPUX 10 does zero padding in this case, */
695 /* Digital Unix and Linux does not. */
696 #if !defined(SOLARIS_COMPATIBLE) && !defined(HPUX_COMPATIBLE)
697 zero_padding = 0; /* turn zero padding off for string conversions */
704 int j = va_arg(ap, int);
705 uchar_arg = (unsigned char) j; /* standard demands unsigned char */
706 str_arg = (const char *) &uchar_arg;
710 str_arg = va_arg(ap, const char *);
711 if (!str_arg) str_arg_l = 0;
712 /* make sure not to address string beyond the specified precision !!! */
713 else if (!precision_specified) str_arg_l = strlen(str_arg);
714 /* truncate string if necessary as requested by precision */
715 else if (precision == 0) str_arg_l = 0;
717 /* memchr on HP does not like n > 2^31 !!! */
718 char *q = (char *) memchr(str_arg, '\0',
719 precision <= 0x7fffffff ? precision : 0x7fffffff);
720 str_arg_l = !q ? precision : (q-str_arg);
726 case 'd': case 'u': case 'o': case 'x': case 'X': case 'p': {
727 /* NOTE: the u, o, x, X and p conversion specifiers imply
728 the value is unsigned; d implies a signed value */
731 /* 0 if numeric argument is zero (or if pointer is NULL for 'p'),
732 +1 if greater than zero (or nonzero for unsigned arguments),
733 -1 if negative (unsigned argument is never negative) */
735 int int_arg = 0; unsigned int uint_arg = 0;
736 /* only defined for length modifier h, or for no length modifiers */
738 long int long_arg = 0; unsigned long int ulong_arg = 0;
739 /* only defined for length modifier l */
741 void *ptr_arg = NULL;
742 /* pointer argument value -only defined for p conversion */
744 #ifdef SNPRINTF_LONGLONG_SUPPORT
745 long long int long_long_arg = 0;
746 unsigned long long int ulong_long_arg = 0;
747 /* only defined for length modifier ll */
749 if (fmt_spec == 'p') {
750 /* HPUX 10: An l, h, ll or L before any other conversion character
751 * (other than d, i, u, o, x, or X) is ignored.
753 * not specified, but seems to behave as HPUX does.
754 * Solaris: If an h, l, or L appears before any other conversion
755 * specifier (other than d, i, u, o, x, or X), the behavior
756 * is undefined. (Actually %hp converts only 16-bits of address
757 * and %llp treats address as 64-bit data which is incompatible
758 * with (void *) argument on a 32-bit system).
760 #ifdef SOLARIS_COMPATIBLE
761 # ifdef SOLARIS_BUG_COMPATIBLE
762 /* keep length modifiers even if it represents 'll' */
764 if (length_modifier == '2') length_modifier = '\0';
767 length_modifier = '\0';
769 ptr_arg = va_arg(ap, void *);
770 if (ptr_arg != NULL) arg_sign = 1;
771 } else if (fmt_spec == 'd') { /* signed */
772 switch (length_modifier) {
775 /* It is non-portable to specify a second argument of char or short
776 * to va_arg, because arguments seen by the called function
777 * are not char or short. C converts char and short arguments
778 * to int before passing them to a function.
780 int_arg = va_arg(ap, int);
781 if (int_arg > 0) arg_sign = 1;
782 else if (int_arg < 0) arg_sign = -1;
785 long_arg = va_arg(ap, long int);
786 if (long_arg > 0) arg_sign = 1;
787 else if (long_arg < 0) arg_sign = -1;
789 #ifdef SNPRINTF_LONGLONG_SUPPORT
791 long_long_arg = va_arg(ap, long long int);
792 if (long_long_arg > 0) arg_sign = 1;
793 else if (long_long_arg < 0) arg_sign = -1;
797 } else { /* unsigned */
798 switch (length_modifier) {
801 uint_arg = va_arg(ap, unsigned int);
802 if (uint_arg) arg_sign = 1;
805 ulong_arg = va_arg(ap, unsigned long int);
806 if (ulong_arg) arg_sign = 1;
808 #ifdef SNPRINTF_LONGLONG_SUPPORT
810 ulong_long_arg = va_arg(ap, unsigned long long int);
811 if (ulong_long_arg) arg_sign = 1;
816 str_arg = tmp; str_arg_l = 0;
818 * For d, i, u, o, x, and X conversions, if precision is specified,
819 * the '0' flag should be ignored. This is so with Solaris 2.6,
820 * Digital UNIX 4.0, HPUX 10, Linux, FreeBSD, NetBSD; but not with Perl.
822 #ifndef PERL_COMPATIBLE
823 if (precision_specified) zero_padding = 0;
825 if (fmt_spec == 'd') {
826 if (force_sign && arg_sign >= 0)
827 tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
828 /* leave negative numbers for sprintf to handle,
829 to avoid handling tricky cases like (short int)(-32768) */
830 #ifdef LINUX_COMPATIBLE
831 } else if (fmt_spec == 'p' && force_sign && arg_sign > 0) {
832 tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
834 } else if (alternate_form) {
835 if (arg_sign != 0 && (fmt_spec == 'x' || fmt_spec == 'X') )
836 { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = fmt_spec; }
837 /* alternate form should have no effect for p conversion, but ... */
838 #ifdef HPUX_COMPATIBLE
839 else if (fmt_spec == 'p'
840 /* HPUX 10: for an alternate form of p conversion,
841 * a nonzero result is prefixed by 0x. */
842 #ifndef HPUX_BUG_COMPATIBLE
843 /* Actually it uses 0x prefix even for a zero value. */
846 ) { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = 'x'; }
849 zero_padding_insertion_ind = str_arg_l;
850 if (!precision_specified) precision = 1; /* default precision is 1 */
851 if (precision == 0 && arg_sign == 0
852 #if defined(HPUX_BUG_COMPATIBLE) || defined(LINUX_COMPATIBLE)
854 /* HPUX 10 man page claims: With conversion character p the result of
855 * converting a zero value with a precision of zero is a null string.
856 * Actually HP returns all zeroes, and Linux returns "(nil)". */
859 /* converted to null string */
860 /* When zero value is formatted with an explicit precision 0,
861 the resulting formatted string is empty (d, i, u, o, x, X, p). */
863 char f[5]; int f_l = 0;
864 f[f_l++] = '%'; /* construct a simple format string for sprintf */
865 if (!length_modifier) { }
866 else if (length_modifier=='2') { f[f_l++] = 'l'; f[f_l++] = 'l'; }
867 else f[f_l++] = length_modifier;
868 f[f_l++] = fmt_spec; f[f_l++] = '\0';
869 if (fmt_spec == 'p') str_arg_l += sprintf(tmp+str_arg_l, f, ptr_arg);
870 else if (fmt_spec == 'd') { /* signed */
871 switch (length_modifier) {
873 case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, int_arg); break;
874 case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, long_arg); break;
875 #ifdef SNPRINTF_LONGLONG_SUPPORT
876 case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,long_long_arg); break;
879 } else { /* unsigned */
880 switch (length_modifier) {
882 case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, uint_arg); break;
883 case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, ulong_arg); break;
884 #ifdef SNPRINTF_LONGLONG_SUPPORT
885 case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,ulong_long_arg);break;
889 /* include the optional minus sign and possible "0x"
890 in the region before the zero padding insertion point */
891 if (zero_padding_insertion_ind < str_arg_l &&
892 tmp[zero_padding_insertion_ind] == '-') {
893 zero_padding_insertion_ind++;
895 if (zero_padding_insertion_ind+1 < str_arg_l &&
896 tmp[zero_padding_insertion_ind] == '0' &&
897 (tmp[zero_padding_insertion_ind+1] == 'x' ||
898 tmp[zero_padding_insertion_ind+1] == 'X') ) {
899 zero_padding_insertion_ind += 2;
902 { size_t num_of_digits = str_arg_l - zero_padding_insertion_ind;
903 if (alternate_form && fmt_spec == 'o'
904 #ifdef HPUX_COMPATIBLE /* ("%#.o",0) -> "" */
907 #ifdef DIGITAL_UNIX_BUG_COMPATIBLE /* ("%#o",0) -> "00" */
909 /* unless zero is already the first character */
910 && !(zero_padding_insertion_ind < str_arg_l
911 && tmp[zero_padding_insertion_ind] == '0')
913 ) { /* assure leading zero for alternate-form octal numbers */
914 if (!precision_specified || precision < num_of_digits+1) {
915 /* precision is increased to force the first character to be zero,
916 except if a zero value is formatted with an explicit precision
918 precision = num_of_digits+1; precision_specified = 1;
921 /* zero padding to specified precision? */
922 if (num_of_digits < precision)
923 number_of_zeros_to_pad = precision - num_of_digits;
925 /* zero padding to specified minimal field width? */
926 if (!justify_left && zero_padding) {
927 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
928 if (n > 0) number_of_zeros_to_pad += n;
932 default: /* unrecognized conversion specifier, keep format string as-is*/
933 zero_padding = 0; /* turn zero padding off for non-numeric convers. */
934 #ifndef DIGITAL_UNIX_COMPATIBLE
935 justify_left = 1; min_field_width = 0; /* reset flags */
937 #if defined(PERL_COMPATIBLE) || defined(LINUX_COMPATIBLE)
938 /* keep the entire format string unchanged */
939 str_arg = starting_p; str_arg_l = p - starting_p;
940 /* well, not exactly so for Linux, which does something inbetween,
941 * and I don't feel an urge to imitate it: "%+++++hy" -> "%+y" */
943 /* discard the unrecognized conversion, just keep *
944 * the unrecognized conversion character */
945 str_arg = p; str_arg_l = 0;
947 if (*p) str_arg_l++; /* include invalid conversion specifier unchanged
948 if not at end-of-string */
951 if (*p) p++; /* step over the just processed conversion specifier */
952 /* insert padding to the left as requested by min_field_width;
953 this does not include the zero padding in case of numerical conversions*/
954 if (!justify_left) { /* left padding with blank or zero */
955 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
958 int avail = str_m-str_l;
959 fast_memset(str+str_l, (zero_padding?'0':' '), (n>avail?avail:n));
964 /* zero padding as requested by the precision or by the minimal field width
965 * for numeric conversions required? */
966 if (number_of_zeros_to_pad <= 0) {
967 /* will not copy first part of numeric right now, *
968 * force it to be copied later in its entirety */
969 zero_padding_insertion_ind = 0;
971 /* insert first part of numerics (sign or '0x') before zero padding */
972 int n = zero_padding_insertion_ind;
975 int avail = str_m-str_l;
976 fast_memcpy(str+str_l, str_arg, (n>avail?avail:n));
980 /* insert zero padding as requested by the precision or min field width */
981 n = number_of_zeros_to_pad;
984 int avail = str_m-str_l;
985 fast_memset(str+str_l, '0', (n>avail?avail:n));
990 /* insert formatted string
991 * (or as-is conversion specifier for unknown conversions) */
992 { int n = str_arg_l - zero_padding_insertion_ind;
995 int avail = str_m-str_l;
996 fast_memcpy(str+str_l, str_arg+zero_padding_insertion_ind,
1002 /* insert right padding */
1003 if (justify_left) { /* right blank padding to the field width */
1004 int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
1006 if (str_l < str_m) {
1007 int avail = str_m-str_l;
1008 fast_memset(str+str_l, ' ', (n>avail?avail:n));
1015 #if defined(NEED_SNPRINTF_ONLY)
1018 if (str_m > 0) { /* make sure the string is null-terminated
1019 even at the expense of overwriting the last character
1020 (shouldn't happen, but just in case) */
1021 str[str_l <= str_m-1 ? str_l : str_m-1] = '\0';
1023 /* Return the number of characters formatted (excluding trailing null
1024 * character), that is, the number of characters that would have been
1025 * written to the buffer if it were large enough.
1027 * The value of str_l should be returned, but str_l is of unsigned type
1028 * size_t, and snprintf is int, possibly leading to an undetected
1029 * integer overflow, resulting in a negative return value, which is illegal.
1030 * Both XSH5 and ISO C99 (at least the draft) are silent on this issue.
1031 * Should errno be set to EOVERFLOW and EOF returned in this case???
1038 /* FIXME: better place */
1039 #include "xbt/sysdep.h"
1041 char *bprintf(const char*fmt, ...) {
1046 vasprintf(&res,fmt,ap);