+/*
+ * 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.
+ */
+
+
+\f
+/* ============================================= */
+/* 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 <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)
+# define breakeven_point 2 /* AXP (DEC Alpha) - gcc or cc or egcs */
+#endif
+#if defined(__i386__) || defined(__i386)
+# define breakeven_point 12 /* Intel Pentium/Linux - gcc 2.96 */
+#endif
+#if defined(__hppa)
+# define breakeven_point 10 /* HP-PA - gcc */
+#endif
+#if defined(__sparc__) || defined(__sparc)
+# define breakeven_point 33 /* Sun Sparc 5 - gcc 2.8.1 */
+#endif
+
+/* some other values of possible interest: */
+/* #define breakeven_point 8 */ /* VAX 4000 - vaxc */
+/* #define breakeven_point 19 */ /* VAX 4000 - gcc 2.7.0 */
+
+#ifndef breakeven_point
+# define breakeven_point 6 /* some reasonable one-size-fits-all value */
+#endif
+
+#define fast_memcpy(d,s,n) \
+ { register size_t nn = (size_t)(n); \
+ if (nn >= breakeven_point) memcpy((d), (s), nn); \
+ else if (nn > 0) { /* proc call overhead is worth only for large strings*/\
+ register char *dd; register const char *ss; \
+ for (ss=(s), dd=(d); nn>0; nn--) *dd++ = *ss++; } }
+
+#define fast_memset(d,c,n) \
+ { register size_t nn = (size_t)(n); \
+ if (nn >= breakeven_point) memset((d), (int)(c), nn); \
+ else if (nn > 0) { /* proc call overhead is worth only for large strings*/\
+ register char *dd; register const int cc=(int)(c); \
+ for (dd=(d); nn>0; nn--) *dd++ = cc; } }
+
+/* prototypes */
+
+#if defined(NEED_ASPRINTF)
+int asprintf (char **ptr, const char *fmt, /*args*/ ...);
+#endif
+#if defined(NEED_VASPRINTF)
+int vasprintf (char **ptr, const char *fmt, va_list ap);
+#endif
+#if defined(NEED_ASNPRINTF)
+int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...);
+#endif
+#if defined(NEED_VASNPRINTF)
+int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap);
+#endif
+
+#if defined(HAVE_SNPRINTF)
+/* declare our portable snprintf routine under name portable_snprintf */
+/* declare our portable vsnprintf routine under name portable_vsnprintf */
+#else
+/* declare our portable routines under names snprintf and vsnprintf */
+#define portable_snprintf snprintf
+#if !defined(NEED_SNPRINTF_ONLY)
+#define portable_vsnprintf vsnprintf
+#endif
+#endif
+
+#if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF)
+int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...);
+#if !defined(NEED_SNPRINTF_ONLY)
+int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap);
+#endif
+#endif
+
+/* declarations */
+
+static char credits[] = "\n\
+@(#)snprintf.c, v2.2: Mark Martinec, <mark.martinec@ijs.si>\n\
+@(#)snprintf.c, v2.2: Copyright 1999, Mark Martinec. Frontier Artistic License applies.\n\
+@(#)snprintf.c, v2.2: http://www.ijs.si/software/snprintf/\n";
+
+#if defined(NEED_ASPRINTF)
+int asprintf(char **ptr, const char *fmt, /*args*/ ...) {
+ va_list ap;
+ size_t str_m;
+ int str_l;
+
+ *ptr = NULL;
+ va_start(ap, fmt); /* measure the required size */
+ str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap);
+ va_end(ap);
+ assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
+ *ptr = (char *) malloc(str_m = (size_t)str_l + 1);
+ if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
+ else {
+ int str_l2;
+ va_start(ap, fmt);
+ str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
+ va_end(ap);
+ assert(str_l2 == str_l);
+ }
+ return str_l;
+}
+#endif
+
+#if defined(NEED_VASPRINTF)
+int vasprintf(char **ptr, const char *fmt, va_list ap) {
+ size_t str_m;
+ int str_l;
+
+ *ptr = NULL;
+ { va_list ap2;
+ va_copy(ap2, ap); /* don't consume the original ap, we'll need it again */
+ str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/
+ va_end(ap2);
+ }
+ assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
+ *ptr = (char *) malloc(str_m = (size_t)str_l + 1);
+ if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
+ else {
+ int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
+ assert(str_l2 == str_l);
+ }
+ return str_l;
+}
+#endif
+
+#if defined(NEED_ASNPRINTF)
+int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...) {
+ va_list ap;
+ int str_l;
+
+ *ptr = NULL;
+ va_start(ap, fmt); /* measure the required size */
+ str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap);
+ va_end(ap);
+ assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
+ if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1; /* truncate */
+ /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */
+ if (str_m == 0) { /* not interested in resulting string, just return size */
+ } else {
+ *ptr = (char *) malloc(str_m);
+ if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
+ else {
+ int str_l2;
+ va_start(ap, fmt);
+ str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
+ va_end(ap);
+ assert(str_l2 == str_l);
+ }
+ }
+ return str_l;
+}
+#endif
+
+#if defined(NEED_VASNPRINTF)
+int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap) {
+ int str_l;
+
+ *ptr = NULL;
+ { va_list ap2;
+ va_copy(ap2, ap); /* don't consume the original ap, we'll need it again */
+ str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/
+ va_end(ap2);
+ }
+ assert(str_l >= 0); /* possible integer overflow if str_m > INT_MAX */
+ if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1; /* truncate */
+ /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */
+ if (str_m == 0) { /* not interested in resulting string, just return size */
+ } else {
+ *ptr = (char *) malloc(str_m);
+ if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
+ else {
+ int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
+ assert(str_l2 == str_l);
+ }
+ }
+ return str_l;
+}
+#endif
+
+/*
+ * If the system does have snprintf and the portable routine is not
+ * specifically required, this module produces no code for snprintf/vsnprintf.
+ */
+#if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF)
+
+#if !defined(NEED_SNPRINTF_ONLY)
+int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
+ va_list ap;
+ int str_l;
+
+ va_start(ap, fmt);
+ str_l = portable_vsnprintf(str, str_m, fmt, ap);
+ va_end(ap);
+ return str_l;
+}
+#endif
+
+#if defined(NEED_SNPRINTF_ONLY)
+int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
+#else
+int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap) {
+#endif
+
+#if defined(NEED_SNPRINTF_ONLY)
+ va_list ap;
+#endif
+ size_t str_l = 0;
+ const char *p = fmt;
+
+/* In contrast with POSIX, the ISO C99 now says
+ * that str can be NULL and str_m can be 0.
+ * This is more useful than the old: if (str_m < 1) return -1; */
+
+#if defined(NEED_SNPRINTF_ONLY)
+ va_start(ap, fmt);
+#endif
+ if (!p) p = "";
+ while (*p) {
+ if (*p != '%') {
+ /* if (str_l < str_m) str[str_l++] = *p++; -- this would be sufficient */
+ /* but the following code achieves better performance for cases
+ * where format string is long and contains few conversions */
+ const char *q = strchr(p+1,'%');
+ size_t n = !q ? strlen(p) : (q-p);
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memcpy(str+str_l, p, (n>avail?avail:n));
+ }
+ p += n; str_l += n;
+ } else {
+ const char *starting_p;
+ size_t min_field_width = 0, precision = 0;
+ int zero_padding = 0, precision_specified = 0, justify_left = 0;
+ int alternate_form = 0, force_sign = 0;
+ int space_for_positive = 1; /* If both the ' ' and '+' flags appear,
+ the ' ' flag should be ignored. */
+ char length_modifier = '\0'; /* allowed values: \0, h, l, L */
+ char tmp[32];/* temporary buffer for simple numeric->string conversion */
+
+ const char *str_arg; /* string address in case of string argument */
+ size_t str_arg_l; /* natural field width of arg without padding
+ and sign */
+ unsigned char uchar_arg;
+ /* unsigned char argument value - only defined for c conversion.
+ N.B. standard explicitly states the char argument for
+ the c conversion is unsigned */
+
+ size_t number_of_zeros_to_pad = 0;
+ /* number of zeros to be inserted for numeric conversions
+ as required by the precision or minimal field width */
+
+ size_t zero_padding_insertion_ind = 0;
+ /* index into tmp where zero padding is to be inserted */
+
+ char fmt_spec = '\0';
+ /* current conversion specifier character */
+
+ str_arg = credits;/* just to make compiler happy (defined but not used)*/
+ str_arg = NULL;
+ starting_p = p; p++; /* skip '%' */
+ /* parse flags */
+ while (*p == '0' || *p == '-' || *p == '+' ||
+ *p == ' ' || *p == '#' || *p == '\'') {
+ switch (*p) {
+ case '0': zero_padding = 1; break;
+ case '-': justify_left = 1; break;
+ case '+': force_sign = 1; space_for_positive = 0; break;
+ case ' ': force_sign = 1;
+ /* If both the ' ' and '+' flags appear, the ' ' flag should be ignored */
+#ifdef PERL_COMPATIBLE
+ /* ... but in Perl the last of ' ' and '+' applies */
+ space_for_positive = 1;
+#endif
+ break;
+ case '#': alternate_form = 1; break;
+ case '\'': break;
+ }
+ p++;
+ }
+ /* If the '0' and '-' flags both appear, the '0' flag should be ignored. */
+
+ /* parse field width */
+ if (*p == '*') {
+ int j;
+ p++; j = va_arg(ap, int);
+ if (j >= 0) min_field_width = j;
+ else { min_field_width = -j; justify_left = 1; }
+ } else if (isdigit((int)(*p))) {
+ /* size_t could be wider than unsigned int;
+ make sure we treat argument like common implementations do */
+ unsigned int uj = *p++ - '0';
+ while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
+ min_field_width = uj;
+ }
+ /* parse precision */
+ if (*p == '.') {
+ p++; precision_specified = 1;
+ if (*p == '*') {
+ int j = va_arg(ap, int);
+ p++;
+ if (j >= 0) precision = j;
+ else {
+ precision_specified = 0; precision = 0;
+ /* NOTE:
+ * Solaris 2.6 man page claims that in this case the precision
+ * should be set to 0. Digital Unix 4.0, HPUX 10 and BSD man page
+ * claim that this case should be treated as unspecified precision,
+ * which is what we do here.
+ */
+ }
+ } else if (isdigit((int)(*p))) {
+ /* size_t could be wider than unsigned int;
+ make sure we treat argument like common implementations do */
+ unsigned int uj = *p++ - '0';
+ while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
+ precision = uj;
+ }
+ }
+ /* parse 'h', 'l' and 'll' length modifiers */
+ if (*p == 'h' || *p == 'l') {
+ length_modifier = *p; p++;
+ if (length_modifier == 'l' && *p == 'l') { /* double l = long long */
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ length_modifier = '2'; /* double l encoded as '2' */
+#else
+ length_modifier = 'l'; /* treat it as a single 'l' */
+#endif
+ p++;
+ }
+ }
+ fmt_spec = *p;
+ /* common synonyms: */
+ switch (fmt_spec) {
+ case 'i': fmt_spec = 'd'; break;
+ case 'D': fmt_spec = 'd'; length_modifier = 'l'; break;
+ case 'U': fmt_spec = 'u'; length_modifier = 'l'; break;
+ case 'O': fmt_spec = 'o'; length_modifier = 'l'; break;
+ default: break;
+ }
+ /* get parameter value, do initial processing */
+ switch (fmt_spec) {
+ case '%': /* % behaves similar to 's' regarding flags and field widths */
+ case 'c': /* c behaves similar to 's' regarding flags and field widths */
+ case 's':
+ length_modifier = '\0'; /* wint_t and wchar_t not supported */
+ /* the result of zero padding flag with non-numeric conversion specifier*/
+ /* is undefined. Solaris and HPUX 10 does zero padding in this case, */
+ /* Digital Unix and Linux does not. */
+#if !defined(SOLARIS_COMPATIBLE) && !defined(HPUX_COMPATIBLE)
+ zero_padding = 0; /* turn zero padding off for string conversions */
+#endif
+ str_arg_l = 1;
+ switch (fmt_spec) {
+ case '%':
+ str_arg = p; break;
+ case 'c': {
+ int j = va_arg(ap, int);
+ uchar_arg = (unsigned char) j; /* standard demands unsigned char */
+ str_arg = (const char *) &uchar_arg;
+ break;
+ }
+ case 's':
+ str_arg = va_arg(ap, const char *);
+ if (!str_arg) str_arg_l = 0;
+ /* make sure not to address string beyond the specified precision !!! */
+ else if (!precision_specified) str_arg_l = strlen(str_arg);
+ /* truncate string if necessary as requested by precision */
+ else if (precision == 0) str_arg_l = 0;
+ else {
+ /* memchr on HP does not like n > 2^31 !!! */
+ const char *q = memchr(str_arg, '\0',
+ precision <= 0x7fffffff ? precision : 0x7fffffff);
+ str_arg_l = !q ? precision : (q-str_arg);
+ }
+ break;
+ default: break;
+ }
+ break;
+ case 'd': case 'u': case 'o': case 'x': case 'X': case 'p': {
+ /* NOTE: the u, o, x, X and p conversion specifiers imply
+ the value is unsigned; d implies a signed value */
+
+ int arg_sign = 0;
+ /* 0 if numeric argument is zero (or if pointer is NULL for 'p'),
+ +1 if greater than zero (or nonzero for unsigned arguments),
+ -1 if negative (unsigned argument is never negative) */
+
+ int int_arg = 0; unsigned int uint_arg = 0;
+ /* only defined for length modifier h, or for no length modifiers */
+
+ long int long_arg = 0; unsigned long int ulong_arg = 0;
+ /* only defined for length modifier l */
+
+ void *ptr_arg = NULL;
+ /* pointer argument value -only defined for p conversion */
+
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ long long int long_long_arg = 0;
+ unsigned long long int ulong_long_arg = 0;
+ /* only defined for length modifier ll */
+#endif
+ if (fmt_spec == 'p') {
+ /* HPUX 10: An l, h, ll or L before any other conversion character
+ * (other than d, i, u, o, x, or X) is ignored.
+ * Digital Unix:
+ * not specified, but seems to behave as HPUX does.
+ * Solaris: If an h, l, or L appears before any other conversion
+ * specifier (other than d, i, u, o, x, or X), the behavior
+ * is undefined. (Actually %hp converts only 16-bits of address
+ * and %llp treats address as 64-bit data which is incompatible
+ * with (void *) argument on a 32-bit system).
+ */
+#ifdef SOLARIS_COMPATIBLE
+# ifdef SOLARIS_BUG_COMPATIBLE
+ /* keep length modifiers even if it represents 'll' */
+# else
+ if (length_modifier == '2') length_modifier = '\0';
+# endif
+#else
+ length_modifier = '\0';
+#endif
+ ptr_arg = va_arg(ap, void *);
+ if (ptr_arg != NULL) arg_sign = 1;
+ } else if (fmt_spec == 'd') { /* signed */
+ switch (length_modifier) {
+ case '\0':
+ case 'h':
+ /* It is non-portable to specify a second argument of char or short
+ * to va_arg, because arguments seen by the called function
+ * are not char or short. C converts char and short arguments
+ * to int before passing them to a function.
+ */
+ int_arg = va_arg(ap, int);
+ if (int_arg > 0) arg_sign = 1;
+ else if (int_arg < 0) arg_sign = -1;
+ break;
+ case 'l':
+ long_arg = va_arg(ap, long int);
+ if (long_arg > 0) arg_sign = 1;
+ else if (long_arg < 0) arg_sign = -1;
+ break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ case '2':
+ long_long_arg = va_arg(ap, long long int);
+ if (long_long_arg > 0) arg_sign = 1;
+ else if (long_long_arg < 0) arg_sign = -1;
+ break;
+#endif
+ }
+ } else { /* unsigned */
+ switch (length_modifier) {
+ case '\0':
+ case 'h':
+ uint_arg = va_arg(ap, unsigned int);
+ if (uint_arg) arg_sign = 1;
+ break;
+ case 'l':
+ ulong_arg = va_arg(ap, unsigned long int);
+ if (ulong_arg) arg_sign = 1;
+ break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ case '2':
+ ulong_long_arg = va_arg(ap, unsigned long long int);
+ if (ulong_long_arg) arg_sign = 1;
+ break;
+#endif
+ }
+ }
+ str_arg = tmp; str_arg_l = 0;
+ /* NOTE:
+ * For d, i, u, o, x, and X conversions, if precision is specified,
+ * the '0' flag should be ignored. This is so with Solaris 2.6,
+ * Digital UNIX 4.0, HPUX 10, Linux, FreeBSD, NetBSD; but not with Perl.
+ */
+#ifndef PERL_COMPATIBLE
+ if (precision_specified) zero_padding = 0;
+#endif
+ if (fmt_spec == 'd') {
+ if (force_sign && arg_sign >= 0)
+ tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
+ /* leave negative numbers for sprintf to handle,
+ to avoid handling tricky cases like (short int)(-32768) */
+#ifdef LINUX_COMPATIBLE
+ } else if (fmt_spec == 'p' && force_sign && arg_sign > 0) {
+ tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
+#endif
+ } else if (alternate_form) {
+ if (arg_sign != 0 && (fmt_spec == 'x' || fmt_spec == 'X') )
+ { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = fmt_spec; }
+ /* alternate form should have no effect for p conversion, but ... */
+#ifdef HPUX_COMPATIBLE
+ else if (fmt_spec == 'p'
+ /* HPUX 10: for an alternate form of p conversion,
+ * a nonzero result is prefixed by 0x. */
+#ifndef HPUX_BUG_COMPATIBLE
+ /* Actually it uses 0x prefix even for a zero value. */
+ && arg_sign != 0
+#endif
+ ) { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = 'x'; }
+#endif
+ }
+ zero_padding_insertion_ind = str_arg_l;
+ if (!precision_specified) precision = 1; /* default precision is 1 */
+ if (precision == 0 && arg_sign == 0
+#if defined(HPUX_BUG_COMPATIBLE) || defined(LINUX_COMPATIBLE)
+ && fmt_spec != 'p'
+ /* HPUX 10 man page claims: With conversion character p the result of
+ * converting a zero value with a precision of zero is a null string.
+ * Actually HP returns all zeroes, and Linux returns "(nil)". */
+#endif
+ ) {
+ /* converted to null string */
+ /* When zero value is formatted with an explicit precision 0,
+ the resulting formatted string is empty (d, i, u, o, x, X, p). */
+ } else {
+ char f[5]; int f_l = 0;
+ f[f_l++] = '%'; /* construct a simple format string for sprintf */
+ if (!length_modifier) { }
+ else if (length_modifier=='2') { f[f_l++] = 'l'; f[f_l++] = 'l'; }
+ else f[f_l++] = length_modifier;
+ f[f_l++] = fmt_spec; f[f_l++] = '\0';
+ if (fmt_spec == 'p') str_arg_l += sprintf(tmp+str_arg_l, f, ptr_arg);
+ else if (fmt_spec == 'd') { /* signed */
+ switch (length_modifier) {
+ case '\0':
+ case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, int_arg); break;
+ case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, long_arg); break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,long_long_arg); break;
+#endif
+ }
+ } else { /* unsigned */
+ switch (length_modifier) {
+ case '\0':
+ case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, uint_arg); break;
+ case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, ulong_arg); break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,ulong_long_arg);break;
+#endif
+ }
+ }
+ /* include the optional minus sign and possible "0x"
+ in the region before the zero padding insertion point */
+ if (zero_padding_insertion_ind < str_arg_l &&
+ tmp[zero_padding_insertion_ind] == '-') {
+ zero_padding_insertion_ind++;
+ }
+ if (zero_padding_insertion_ind+1 < str_arg_l &&
+ tmp[zero_padding_insertion_ind] == '0' &&
+ (tmp[zero_padding_insertion_ind+1] == 'x' ||
+ tmp[zero_padding_insertion_ind+1] == 'X') ) {
+ zero_padding_insertion_ind += 2;
+ }
+ }
+ { size_t num_of_digits = str_arg_l - zero_padding_insertion_ind;
+ if (alternate_form && fmt_spec == 'o'
+#ifdef HPUX_COMPATIBLE /* ("%#.o",0) -> "" */
+ && (str_arg_l > 0)
+#endif
+#ifdef DIGITAL_UNIX_BUG_COMPATIBLE /* ("%#o",0) -> "00" */
+#else
+ /* unless zero is already the first character */
+ && !(zero_padding_insertion_ind < str_arg_l
+ && tmp[zero_padding_insertion_ind] == '0')
+#endif
+ ) { /* assure leading zero for alternate-form octal numbers */
+ if (!precision_specified || precision < num_of_digits+1) {
+ /* precision is increased to force the first character to be zero,
+ except if a zero value is formatted with an explicit precision
+ of zero */
+ precision = num_of_digits+1; precision_specified = 1;
+ }
+ }
+ /* zero padding to specified precision? */
+ if (num_of_digits < precision)
+ number_of_zeros_to_pad = precision - num_of_digits;
+ }
+ /* zero padding to specified minimal field width? */
+ if (!justify_left && zero_padding) {
+ int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+ if (n > 0) number_of_zeros_to_pad += n;
+ }
+ break;
+ }
+ default: /* unrecognized conversion specifier, keep format string as-is*/
+ zero_padding = 0; /* turn zero padding off for non-numeric convers. */
+#ifndef DIGITAL_UNIX_COMPATIBLE
+ justify_left = 1; min_field_width = 0; /* reset flags */
+#endif
+#if defined(PERL_COMPATIBLE) || defined(LINUX_COMPATIBLE)
+ /* keep the entire format string unchanged */
+ str_arg = starting_p; str_arg_l = p - starting_p;
+ /* well, not exactly so for Linux, which does something inbetween,
+ * and I don't feel an urge to imitate it: "%+++++hy" -> "%+y" */
+#else
+ /* discard the unrecognized conversion, just keep *
+ * the unrecognized conversion character */
+ str_arg = p; str_arg_l = 0;
+#endif
+ if (*p) str_arg_l++; /* include invalid conversion specifier unchanged
+ if not at end-of-string */
+ break;
+ }
+ if (*p) p++; /* step over the just processed conversion specifier */
+ /* insert padding to the left as requested by min_field_width;
+ this does not include the zero padding in case of numerical conversions*/
+ if (!justify_left) { /* left padding with blank or zero */
+ int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memset(str+str_l, (zero_padding?'0':' '), (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ }
+ /* zero padding as requested by the precision or by the minimal field width
+ * for numeric conversions required? */
+ if (number_of_zeros_to_pad <= 0) {
+ /* will not copy first part of numeric right now, *
+ * force it to be copied later in its entirety */
+ zero_padding_insertion_ind = 0;
+ } else {
+ /* insert first part of numerics (sign or '0x') before zero padding */
+ int n = zero_padding_insertion_ind;
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memcpy(str+str_l, str_arg, (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ /* insert zero padding as requested by the precision or min field width */
+ n = number_of_zeros_to_pad;
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memset(str+str_l, '0', (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ }
+ /* insert formatted string
+ * (or as-is conversion specifier for unknown conversions) */
+ { int n = str_arg_l - zero_padding_insertion_ind;
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memcpy(str+str_l, str_arg+zero_padding_insertion_ind,
+ (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ }
+ /* insert right padding */
+ if (justify_left) { /* right blank padding to the field width */
+ int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memset(str+str_l, ' ', (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ }
+ }
+ }
+#if defined(NEED_SNPRINTF_ONLY)
+ va_end(ap);
+#endif
+ if (str_m > 0) { /* make sure the string is null-terminated
+ even at the expense of overwriting the last character
+ (shouldn't happen, but just in case) */
+ str[str_l <= str_m-1 ? str_l : str_m-1] = '\0';
+ }
+ /* Return the number of characters formatted (excluding trailing null
+ * character), that is, the number of characters that would have been
+ * written to the buffer if it were large enough.
+ *
+ * The value of str_l should be returned, but str_l is of unsigned type
+ * size_t, and snprintf is int, possibly leading to an undetected
+ * integer overflow, resulting in a negative return value, which is illegal.
+ * Both XSH5 and ISO C99 (at least the draft) are silent on this issue.
+ * Should errno be set to EOVERFLOW and EOF returned in this case???
+ */
+ return (int) str_l;
+}
+#endif
~ian / secnet.git / commitdiff