/* * snprintf.c - a portable implementation of snprintf * * AUTHOR *   Mark Martinec <mark.martinec@ijs.si>, April 1999. * *   Copyright 1999, Mark Martinec. All rights reserved. * * TERMS AND CONDITIONS *   This program is free software; you can redistribute it and/or modify *   it under the terms of the "Frontier Artistic License" which comes *   with this Kit. * *   This program is distributed in the hope that it will be useful, *   but WITHOUT ANY WARRANTY; without even the implied warranty *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. *   See the Frontier Artistic License for more details. * *   You should have received a copy of the Frontier Artistic License *   with this Kit in the file named LICENSE.txt . *   If not, I'll be glad to provide one. * * FEATURES * - careful adherence to specs regarding flags, field width and precision; * - good performance for large string handling (large format, large *   argument or large paddings). Performance is similar to system's sprintf *   and in several cases significantly better (make sure you compile with *   optimizations turned on, tell the compiler the code is strict ANSI *   if necessary to give it more freedom for optimizations); * - return value semantics per ISO/IEC 9899:1999 ("ISO C99"); * - written in standard ISO/ANSI C - requires an ANSI C compiler. * * SUPPORTED CONVERSION SPECIFIERS AND DATA TYPES * * This snprintf only supports the following conversion specifiers: * s, c, d, u, o, x, X, p  (and synonyms: i, D, U, O - see below) * with flags: '-', '+', ' ', '0' and '#'. * An asterisk is supported for field width as well as precision. * * Length modifiers 'h' (short int), 'l' (long int), * and 'll' (long long int) are supported. * NOTE: *   If macro SNPRINTF_LONGLONG_SUPPORT is not defined (default) the *   length modifier 'll' is recognized but treated the same as 'l', *   which may cause argument value truncation! Defining *   SNPRINTF_LONGLONG_SUPPORT requires that your system's sprintf also *   handles length modifier 'll'.  long long int is a language extension *   which may not be portable. * * Conversion of numeric data (conversion specifiers d, u, o, x, X, p) * with length modifiers (none or h, l, ll) is left to the system routine * sprintf, but all handling of flags, field width and precision as well as * c and s conversions is done very carefully by this portable routine. * If a string precision (truncation) is specified (e.g. %.8s) it is * guaranteed the string beyond the specified precision will not be referenced. * * Length modifiers h, l and ll are ignored for c and s conversions (data * types wint_t and wchar_t are not supported). * * The following common synonyms for conversion characters are supported: *   - i is a synonym for d *   - D is a synonym for ld, explicit length modifiers are ignored *   - U is a synonym for lu, explicit length modifiers are ignored *   - O is a synonym for lo, explicit length modifiers are ignored * The D, O and U conversion characters are nonstandard, they are supported * for backward compatibility only, and should not be used for new code. * * The following is specifically NOT supported: *   - flag ' (thousands' grouping character) is recognized but ignored *   - numeric conversion specifiers: f, e, E, g, G and synonym F, *     as well as the new a and A conversion specifiers *   - length modifier 'L' (long double) and 'q' (quad - use 'll' instead) *   - wide character/string conversions: lc, ls, and nonstandard *     synonyms C and S *   - writeback of converted string length: conversion character n *   - the n$ specification for direct reference to n-th argument *   - locales * * It is permitted for str_m to be zero, and it is permitted to specify NULL * pointer for resulting string argument if str_m is zero (as per ISO C99). * * The return value is the number of characters which would be generated * for the given input, excluding the trailing null. If this value * is greater or equal to str_m, not all characters from the result * have been stored in str, output bytes beyond the (str_m-1) -th character * are discarded. If str_m is greater than zero it is guaranteed * the resulting string will be null-terminated. * * NOTE that this matches the ISO C99, OpenBSD, and GNU C library 2.1, * but is different from some older and vendor implementations, * and is also different from XPG, XSH5, SUSv2 specifications. * For historical discussion on changes in the semantics and standards * of snprintf see printf(3) man page in the Linux programmers manual. * * Routines asprintf and vasprintf return a pointer (in the ptr argument) * to a buffer sufficiently large to hold the resulting string. This pointer * should be passed to free(3) to release the allocated storage when it is * no longer needed. If sufficient space cannot be allocated, these functions * will return -1 and set ptr to be a NULL pointer. These two routines are a * GNU C library extensions (glibc). * * Routines asnprintf and vasnprintf are similar to asprintf and vasprintf, * yet, like snprintf and vsnprintf counterparts, will write at most str_m-1 * characters into the allocated output string, the last character in the * allocated buffer then gets the terminating null. If the formatted string * length (the return value) is greater than or equal to the str_m argument, * the resulting string was truncated and some of the formatted characters * were discarded. These routines present a handy way to limit the amount * of allocated memory to some sane value. * * AVAILABILITY *   http://www.ijs.si/software/snprintf/ * * REVISION HISTORY * 1999-04	V0.9  Mark Martinec *		- initial version, some modifications after comparing printf *		  man pages for Digital Unix 4.0, Solaris 2.6 and HPUX 10, *		  and checking how Perl handles sprintf (differently!); * 1999-04-09	V1.0  Mark Martinec <mark.martinec@ijs.si> *		- added main test program, fixed remaining inconsistencies, *		  added optional (long long int) support; * 1999-04-12	V1.1  Mark Martinec <mark.martinec@ijs.si> *		- support the 'p' conversion (pointer to void); *		- if a string precision is specified *		  make sure the string beyond the specified precision *		  will not be referenced (e.g. by strlen); * 1999-04-13	V1.2  Mark Martinec <mark.martinec@ijs.si> *		- support synonyms %D=%ld, %U=%lu, %O=%lo; *		- speed up the case of long format string with few conversions; * 1999-06-30	V1.3  Mark Martinec <mark.martinec@ijs.si> *		- fixed runaway loop (eventually crashing when str_l wraps *		  beyond 2^31) while copying format string without *		  conversion specifiers to a buffer that is too short *		  (thanks to Edwin Young <edwiny@autonomy.com> for *		  spotting the problem); *		- added macros PORTABLE_SNPRINTF_VERSION_(MAJOR|MINOR) *		  to snprintf.h * 2000-02-14	V2.0 (never released) Mark Martinec <mark.martinec@ijs.si> *		- relaxed license terms: The Artistic License now applies. *		  You may still apply the GNU GENERAL PUBLIC LICENSE *		  as was distributed with previous versions, if you prefer; *		- changed REVISION HISTORY dates to use ISO 8601 date format; *		- added vsnprintf (patch also independently proposed by *		  Caolan McNamara 2000-05-04, and Keith M Willenson 2000-06-01) * 2000-06-27	V2.1  Mark Martinec <mark.martinec@ijs.si> *		- removed POSIX check for str_m<1; value 0 for str_m is *		  allowed by ISO C99 (and GNU C library 2.1) - (pointed out *		  on 2000-05-04 by Caolan McNamara, caolan@ csn dot ul dot ie). *		  Besides relaxed license this change in standards adherence *		  is the main reason to bump up the major version number; *		- added nonstandard routines asnprintf, vasnprintf, asprintf, *		  vasprintf that dynamically allocate storage for the *		  resulting string; these routines are not compiled by default, *		  see comments where NEED_V?ASN?PRINTF macros are defined; *		- autoconf contributed by Caolan McNamara * 2000-10-06	V2.2  Mark Martinec <mark.martinec@ijs.si> *		- BUG FIX: the %c conversion used a temporary variable *		  that was no longer in scope when referenced, *		  possibly causing incorrect resulting character; *		- BUG FIX: make precision and minimal field width unsigned *		  to handle huge values (2^31 <= n < 2^32) correctly; *		  also be more careful in the use of signed/unsigned/size_t *		  internal variables - probably more careful than many *		  vendor implementations, but there may still be a case *		  where huge values of str_m, precision or minimal field *		  could cause incorrect behaviour; *		- use separate variables for signed/unsigned arguments, *		  and for short/int, long, and long long argument lengths *		  to avoid possible incompatibilities on certain *		  computer architectures. Also use separate variable *		  arg_sign to hold sign of a numeric argument, *		  to make code more transparent; *		- some fiddling with zero padding and "0x" to make it *		  Linux compatible; *		- systematically use macros fast_memcpy and fast_memset *		  instead of case-by-case hand optimization; determine some *		  breakeven string lengths for different architectures; *		- terminology change: 'format' -> 'conversion specifier', *		  'C9x' -> 'ISO/IEC 9899:1999 ("ISO C99")', *		  'alternative form' -> 'alternate form', *		  'data type modifier' -> 'length modifier'; *		- several comments rephrased and new ones added; *		- make compiler not complain about 'credits' defined but *		  not used; *//* Define HAVE_SNPRINTF if your system already has snprintf and vsnprintf. * * If HAVE_SNPRINTF is defined this module will not produce code for * snprintf and vsnprintf, unless PREFER_PORTABLE_SNPRINTF is defined as well, * causing this portable version of snprintf to be called portable_snprintf * (and portable_vsnprintf). *//* #define HAVE_SNPRINTF *//* Define PREFER_PORTABLE_SNPRINTF if your system does have snprintf and * vsnprintf but you would prefer to use the portable routine(s) instead. * In this case the portable routine is declared as portable_snprintf * (and portable_vsnprintf) and a macro 'snprintf' (and 'vsnprintf') * is defined to expand to 'portable_v?snprintf' - see file snprintf.h . * Defining this macro is only useful if HAVE_SNPRINTF is also defined, * but does does no harm if defined nevertheless. *//* #define PREFER_PORTABLE_SNPRINTF *//* Define SNPRINTF_LONGLONG_SUPPORT if you want to support * data type (long long int) and length modifier 'll' (e.g. %lld). * If undefined, 'll' is recognized but treated as a single 'l'. * * If the system's sprintf does not handle 'll' * the SNPRINTF_LONGLONG_SUPPORT must not be defined! * * This is off by default as (long long int) is a language extension. *//* #define SNPRINTF_LONGLONG_SUPPORT *//* Define NEED_SNPRINTF_ONLY if you only need snprintf, and not vsnprintf. * If NEED_SNPRINTF_ONLY is defined, the snprintf will be defined directly, * otherwise both snprintf and vsnprintf routines will be defined * and snprintf will be a simple wrapper around vsnprintf, at the expense * of an extra procedure call. *//* #define NEED_SNPRINTF_ONLY *//* Define NEED_V?ASN?PRINTF macros if you need library extension * routines asprintf, vasprintf, asnprintf, vasnprintf respectively, * and your system library does not provide them. They are all small * wrapper routines around portable_vsnprintf. Defining any of the four * NEED_V?ASN?PRINTF macros automatically turns off NEED_SNPRINTF_ONLY * and turns on PREFER_PORTABLE_SNPRINTF. * * Watch for name conflicts with the system library if these routines * are already present there. * * NOTE: vasprintf and vasnprintf routines need va_copy() from stdarg.h, as * specified by C99, to be able to traverse the same list of arguments twice. * I don't know of any other standard and portable way of achieving the same. * With some versions of gcc you may use __va_copy(). You might even get away * with "ap2 = ap", in this case you must not call va_end(ap2) ! *   #define va_copy(ap2,ap) ap2 = ap *//* #define NEED_ASPRINTF   *//* #define NEED_ASNPRINTF  *//* #define NEED_VASPRINTF  *//* #define NEED_VASNPRINTF *//* Define the following macros if desired: *   SOLARIS_COMPATIBLE, SOLARIS_BUG_COMPATIBLE, *   HPUX_COMPATIBLE, HPUX_BUG_COMPATIBLE, LINUX_COMPATIBLE, *   DIGITAL_UNIX_COMPATIBLE, DIGITAL_UNIX_BUG_COMPATIBLE, *   PERL_COMPATIBLE, PERL_BUG_COMPATIBLE, * * - For portable applications it is best not to rely on peculiarities *   of a given implementation so it may be best not to define any *   of the macros that select compatibility and to avoid features *   that vary among the systems. * * - Selecting compatibility with more than one operating system *   is not strictly forbidden but is not recommended. * * - 'x'_BUG_COMPATIBLE implies 'x'_COMPATIBLE . * * - 'x'_COMPATIBLE refers to (and enables) a behaviour that is *   documented in a sprintf man page on a given operating system *   and actually adhered to by the system's sprintf (but not on *   most other operating systems). It may also refer to and enable *   a behaviour that is declared 'undefined' or 'implementation specific' *   in the man page but a given implementation behaves predictably *   in a certain way. * * - 'x'_BUG_COMPATIBLE refers to (and enables) a behaviour of system's sprintf *   that contradicts the sprintf man page on the same operating system. * * - I do not claim that the 'x'_COMPATIBLE and 'x'_BUG_COMPATIBLE *   conditionals take into account all idiosyncrasies of a particular *   implementation, there may be other incompatibilities. *//* ============================================= *//* NO USER SERVICABLE PARTS FOLLOWING THIS POINT *//* ============================================= */#define PORTABLE_SNPRINTF_VERSION_MAJOR 2#define PORTABLE_SNPRINTF_VERSION_MINOR 2#if defined(NEED_ASPRINTF) || defined(NEED_ASNPRINTF) || defined(NEED_VASPRINTF) || defined(NEED_VASNPRINTF)# if defined(NEED_SNPRINTF_ONLY)# undef NEED_SNPRINTF_ONLY# endif# if !defined(PREFER_PORTABLE_SNPRINTF)# define PREFER_PORTABLE_SNPRINTF# endif#endif#if defined(SOLARIS_BUG_COMPATIBLE) && !defined(SOLARIS_COMPATIBLE)#define SOLARIS_COMPATIBLE#endif#if defined(HPUX_BUG_COMPATIBLE) && !defined(HPUX_COMPATIBLE)#define HPUX_COMPATIBLE#endif#if defined(DIGITAL_UNIX_BUG_COMPATIBLE) && !defined(DIGITAL_UNIX_COMPATIBLE)#define DIGITAL_UNIX_COMPATIBLE#endif#if defined(PERL_BUG_COMPATIBLE) && !defined(PERL_COMPATIBLE)#define PERL_COMPATIBLE#endif#if defined(LINUX_BUG_COMPATIBLE) && !defined(LINUX_COMPATIBLE)#define LINUX_COMPATIBLE#endif#include <config.h>#include <sys/types.h>#include <string.h>#include <stdlib.h>#include <stdio.h>#include <stdarg.h>#include <assert.h>#include <errno.h>#ifdef isdigit#undef isdigit#endif#define isdigit(c) ((c) >= '0' && (c) <= '9')/* For copying strings longer or equal to 'breakeven_point' * it is more efficient to call memcpy() than to do it inline. * The value depends mostly on the processor architecture, * but also on the compiler and its optimization capabilities. * The value is not critical, some small value greater than zero * will be just fine if you don't care to squeeze every drop * of performance out of the code. * * Small values favor memcpy, large values favor inline code. */#if defined(__alpha__) || defined(__alpha)