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snprintf.c
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/*
* snprintf.c - a portable implementation of snprintf
*
* AUTHOR
* Mark Martinec <[email protected]>, 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 <[email protected]>
* - added main test program, fixed remaining inconsistencies,
* added optional (long long int) support;
* 1999-04-12 V1.1 Mark Martinec <[email protected]>
* - 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 <[email protected]>
* - 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 <[email protected]>
* - 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 <[email protected]> for
* spotting the problem);
* - added macros PORTABLE_SNPRINTF_VERSION_(MAJOR|MINOR)
* to snprintf.h
* 2000-02-14 V2.0 (never released) Mark Martinec <[email protected]>
* - 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 <[email protected]>
* - 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 <[email protected]>
* - 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 <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, <[email protected]>\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;
}
}