mini/vsprintf.c

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/*
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* Copyright (c) 1995 Patrick Powell.
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*
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* This code is based on code written by Patrick Powell <papowell@astart.com>.
* It may be used for any purpose as long as this notice remains intact on all
* source code distributions.
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* Copyright (c) 2008 Holger Weiss.
*
* This version of the code is maintained by Holger Weiss <holger@jhweiss.de>.
* My changes to the code may freely be used, modified and/or redistributed for
* any purpose. It would be nice if additions and fixes to this file (including
* trivial code cleanups) would be sent back in order to let me include them in
* the version available at <http://www.jhweiss.de/software/snprintf.html>.
* However, this is not a requirement for using or redistributing (possibly
* modified) versions of this file, nor is leaving this notice intact mandatory.
*/
/*
* History
*
* 2009-03-05 Hector Martin "marcan" <marcan@marcansoft.com>
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*
* Hacked up and removed a lot of stuff including floating-point support,
* a bunch of ifs and defines, locales, and tests
*
* 2008-01-20 Holger Weiss <holger@jhweiss.de> for C99-snprintf 1.1:
*
* Fixed the detection of infinite floating point values on IRIX (and
* possibly other systems) and applied another few minor cleanups.
*
* 2008-01-06 Holger Weiss <holger@jhweiss.de> for C99-snprintf 1.0:
*
* Added a lot of new features, fixed many bugs, and incorporated various
* improvements done by Andrew Tridgell <tridge@samba.org>, Russ Allbery
* <rra@stanford.edu>, Hrvoje Niksic <hniksic@xemacs.org>, Damien Miller
* <djm@mindrot.org>, and others for the Samba, INN, Wget, and OpenSSH
* projects. The additions include: support the "e", "E", "g", "G", and
* "F" conversion specifiers (and use conversion style "f" or "F" for the
* still unsupported "a" and "A" specifiers); support the "hh", "ll", "j",
* "t", and "z" length modifiers; support the "#" flag and the (non-C99)
* "'" flag; use localeconv(3) (if available) to get both the current
* locale's decimal point character and the separator between groups of
* digits; fix the handling of various corner cases of field width and
* precision specifications; fix various floating point conversion bugs;
* handle infinite and NaN floating point values; don't attempt to write to
* the output buffer (which may be NULL) if a size of zero was specified;
* check for integer overflow of the field width, precision, and return
* values and during the floating point conversion; use the OUTCHAR() macro
* instead of a function for better performance; provide asprintf(3) and
* vasprintf(3) functions; add new test cases. The replacement functions
* have been renamed to use an "rpl_" prefix, the function calls in the
* main project (and in this file) must be redefined accordingly for each
* replacement function which is needed (by using Autoconf or other means).
* Various other minor improvements have been applied and the coding style
* was cleaned up for consistency.
*
* 2007-07-23 Holger Weiss <holger@jhweiss.de> for Mutt 1.5.13:
*
* C99 compliant snprintf(3) and vsnprintf(3) functions return the number
* of characters that would have been written to a sufficiently sized
* buffer (excluding the '\0'). The original code simply returned the
* length of the resulting output string, so that's been fixed.
*
* 1998-03-05 Michael Elkins <me@mutt.org> for Mutt 0.90.8:
*
* The original code assumed that both snprintf(3) and vsnprintf(3) were
* missing. Some systems only have snprintf(3) but not vsnprintf(3), so
* the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
*
* 1998-01-27 Thomas Roessler <roessler@does-not-exist.org> for Mutt 0.89i:
*
* The PGP code was using unsigned hexadecimal formats. Unfortunately,
* unsigned formats simply didn't work.
*
* 1997-10-22 Brandon Long <blong@fiction.net> for Mutt 0.87.1:
*
* Ok, added some minimal floating point support, which means this probably
* requires libm on most operating systems. Don't yet support the exponent
* (e,E) and sigfig (g,G). Also, fmtint() was pretty badly broken, it just
* wasn't being exercised in ways which showed it, so that's been fixed.
* Also, formatted the code to Mutt conventions, and removed dead code left
* over from the original. Also, there is now a builtin-test, run with:
* gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm && ./snprintf
*
* 2996-09-15 Brandon Long <blong@fiction.net> for Mutt 0.43:
*
* This was ugly. It is still ugly. I opted out of floating point
* numbers, but the formatter understands just about everything from the
* normal C string format, at least as far as I can tell from the Solaris
* 2.5 printf(3S) man page.
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*/
#include <stdarg.h>
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#include "types.h"
#define VA_START(ap, last) va_start(ap, last)
#define VA_SHIFT(ap, value, type) /* No-op for ANSI C. */
#define ULLONG unsigned long
#define UINTMAX_T unsigned long
#define UINTMAX_MAX ULONG_MAX
#define LLONG long
#define INTMAX_T long
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/* Support for uintptr_t. */
#ifndef UINTPTR_T
#if HAVE_UINTPTR_T || defined(uintptr_t)
#define UINTPTR_T uintptr_t
#else
#define UINTPTR_T unsigned long int
#endif /* HAVE_UINTPTR_T || defined(uintptr_t) */
#endif /* !defined(UINTPTR_T) */
/* Support for ptrdiff_t. */
#ifndef PTRDIFF_T
#if HAVE_PTRDIFF_T || defined(ptrdiff_t)
#define PTRDIFF_T ptrdiff_t
#else
#define PTRDIFF_T long int
#endif /* HAVE_PTRDIFF_T || defined(ptrdiff_t) */
#endif /* !defined(PTRDIFF_T) */
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/*
* We need an unsigned integer type corresponding to ptrdiff_t (cf. C99:
* 7.19.6.1, 7). However, we'll simply use PTRDIFF_T and convert it to an
* unsigned type if necessary. This should work just fine in practice.
*/
#ifndef UPTRDIFF_T
#define UPTRDIFF_T PTRDIFF_T
#endif /* !defined(UPTRDIFF_T) */
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/*
* We need a signed integer type corresponding to size_t (cf. C99: 7.19.6.1, 7).
* However, we'll simply use size_t and convert it to a signed type if
* necessary. This should work just fine in practice.
*/
#ifndef SSIZE_T
#define SSIZE_T size_t
#endif /* !defined(SSIZE_T) */
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/*
* Buffer size to hold the octal string representation of UINT128_MAX without
* nul-termination ("3777777777777777777777777777777777777777777").
*/
#ifdef MAX_CONVERT_LENGTH
#undef MAX_CONVERT_LENGTH
#endif /* defined(MAX_CONVERT_LENGTH) */
#define MAX_CONVERT_LENGTH 43
/* Format read states. */
#define PRINT_S_DEFAULT 0
#define PRINT_S_FLAGS 1
#define PRINT_S_WIDTH 2
#define PRINT_S_DOT 3
#define PRINT_S_PRECISION 4
#define PRINT_S_MOD 5
#define PRINT_S_CONV 6
/* Format flags. */
#define PRINT_F_MINUS (1 << 0)
#define PRINT_F_PLUS (1 << 1)
#define PRINT_F_SPACE (1 << 2)
#define PRINT_F_NUM (1 << 3)
#define PRINT_F_ZERO (1 << 4)
#define PRINT_F_QUOTE (1 << 5)
#define PRINT_F_UP (1 << 6)
#define PRINT_F_UNSIGNED (1 << 7)
#define PRINT_F_TYPE_G (1 << 8)
#define PRINT_F_TYPE_E (1 << 9)
/* Conversion flags. */
#define PRINT_C_CHAR 1
#define PRINT_C_SHORT 2
#define PRINT_C_LONG 3
#define PRINT_C_LLONG 4
//#define PRINT_C_LDOUBLE 5
#define PRINT_C_SIZE 6
#define PRINT_C_PTRDIFF 7
#define PRINT_C_INTMAX 8
#ifndef MAX
#define MAX(x, y) ((x >= y) ? x : y)
#endif /* !defined(MAX) */
#ifndef CHARTOINT
#define CHARTOINT(ch) (ch - '0')
#endif /* !defined(CHARTOINT) */
#ifndef ISDIGIT
#define ISDIGIT(ch) ('0' <= (unsigned char)ch && (unsigned char)ch <= '9')
#endif /* !defined(ISDIGIT) */
#define OUTCHAR(str, len, size, ch) \
do { \
if (len + 1 < size) \
str[len] = ch; \
(len)++; \
} while (/* CONSTCOND */ 0)
static void fmtstr(char *, size_t *, size_t, const char *, int, int, int);
static void fmtint(char *, size_t *, size_t, INTMAX_T, int, int, int, int);
static void printsep(char *, size_t *, size_t);
static int getnumsep(int);
static int convert(UINTMAX_T, char *, size_t, int, int);
int vsnprintf(char *str, size_t size, const char *format, va_list args)
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{
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INTMAX_T value;
unsigned char cvalue;
const char *strvalue;
INTMAX_T *intmaxptr;
PTRDIFF_T *ptrdiffptr;
SSIZE_T *sizeptr;
LLONG *llongptr;
long int *longptr;
int *intptr;
short int *shortptr;
signed char *charptr;
size_t len = 0;
int overflow = 0;
int base = 0;
int cflags = 0;
int flags = 0;
int width = 0;
int precision = -1;
int state = PRINT_S_DEFAULT;
char ch = *format++;
/*
* C99 says: "If `n' is zero, nothing is written, and `s' may be a null
* pointer." (7.19.6.5, 2) We're forgiving and allow a NULL pointer
* even if a size larger than zero was specified. At least NetBSD's
* snprintf(3) does the same, as well as other versions of this file.
* (Though some of these versions will write to a non-NULL buffer even
* if a size of zero was specified, which violates the standard.)
*/
if (str == NULL && size != 0)
size = 0;
while (ch != '\0')
switch (state) {
case PRINT_S_DEFAULT:
if (ch == '%')
state = PRINT_S_FLAGS;
else
OUTCHAR(str, len, size, ch);
ch = *format++;
break;
case PRINT_S_FLAGS:
switch (ch) {
case '-':
flags |= PRINT_F_MINUS;
ch = *format++;
break;
case '+':
flags |= PRINT_F_PLUS;
ch = *format++;
break;
case ' ':
flags |= PRINT_F_SPACE;
ch = *format++;
break;
case '#':
flags |= PRINT_F_NUM;
ch = *format++;
break;
case '0':
flags |= PRINT_F_ZERO;
ch = *format++;
break;
case '\'': /* SUSv2 flag (not in C99). */
flags |= PRINT_F_QUOTE;
ch = *format++;
break;
default:
state = PRINT_S_WIDTH;
break;
}
break;
case PRINT_S_WIDTH:
if (ISDIGIT(ch)) {
ch = CHARTOINT(ch);
if (width > (INT_MAX - ch) / 10) {
overflow = 1;
goto out;
}
width = 10 * width + ch;
ch = *format++;
} else if (ch == '*') {
/*
* C99 says: "A negative field width argument is
* taken as a `-' flag followed by a positive
* field width." (7.19.6.1, 5)
*/
if ((width = va_arg(args, int)) < 0) {
flags |= PRINT_F_MINUS;
width = -width;
}
ch = *format++;
state = PRINT_S_DOT;
} else
state = PRINT_S_DOT;
break;
case PRINT_S_DOT:
if (ch == '.') {
state = PRINT_S_PRECISION;
ch = *format++;
} else
state = PRINT_S_MOD;
break;
case PRINT_S_PRECISION:
if (precision == -1)
precision = 0;
if (ISDIGIT(ch)) {
ch = CHARTOINT(ch);
if (precision > (INT_MAX - ch) / 10) {
overflow = 1;
goto out;
}
precision = 10 * precision + ch;
ch = *format++;
} else if (ch == '*') {
/*
* C99 says: "A negative precision argument is
* taken as if the precision were omitted."
* (7.19.6.1, 5)
*/
if ((precision = va_arg(args, int)) < 0)
precision = -1;
ch = *format++;
state = PRINT_S_MOD;
} else
state = PRINT_S_MOD;
break;
case PRINT_S_MOD:
switch (ch) {
case 'h':
ch = *format++;
if (ch == 'h') { /* It's a char. */
ch = *format++;
cflags = PRINT_C_CHAR;
} else
cflags = PRINT_C_SHORT;
break;
case 'l':
ch = *format++;
if (ch == 'l') { /* It's a long long. */
ch = *format++;
cflags = PRINT_C_LLONG;
} else
cflags = PRINT_C_LONG;
break;
case 'j':
cflags = PRINT_C_INTMAX;
ch = *format++;
break;
case 't':
cflags = PRINT_C_PTRDIFF;
ch = *format++;
break;
case 'z':
cflags = PRINT_C_SIZE;
ch = *format++;
break;
}
state = PRINT_S_CONV;
break;
case PRINT_S_CONV:
switch (ch) {
case 'd':
/* FALLTHROUGH */
case 'i':
switch (cflags) {
case PRINT_C_CHAR:
value = (signed char)va_arg(args, int);
break;
case PRINT_C_SHORT:
value = (short int)va_arg(args, int);
break;
case PRINT_C_LONG:
value = va_arg(args, long int);
break;
case PRINT_C_LLONG:
value = va_arg(args, LLONG);
break;
case PRINT_C_SIZE:
value = va_arg(args, SSIZE_T);
break;
case PRINT_C_INTMAX:
value = va_arg(args, INTMAX_T);
break;
case PRINT_C_PTRDIFF:
value = va_arg(args, PTRDIFF_T);
break;
default:
value = va_arg(args, int);
break;
}
fmtint(str, &len, size, value, 10, width,
precision, flags);
break;
case 'X':
flags |= PRINT_F_UP;
/* FALLTHROUGH */
case 'x':
base = 16;
/* FALLTHROUGH */
case 'o':
if (base == 0)
base = 8;
/* FALLTHROUGH */
case 'u':
if (base == 0)
base = 10;
flags |= PRINT_F_UNSIGNED;
switch (cflags) {
case PRINT_C_CHAR:
value = (unsigned char)va_arg(args,
unsigned int);
break;
case PRINT_C_SHORT:
value = (unsigned short int)va_arg(args,
unsigned int);
break;
case PRINT_C_LONG:
value = va_arg(args, unsigned long int);
break;
case PRINT_C_LLONG:
value = va_arg(args, ULLONG);
break;
case PRINT_C_SIZE:
value = va_arg(args, size_t);
break;
case PRINT_C_INTMAX:
value = va_arg(args, UINTMAX_T);
break;
case PRINT_C_PTRDIFF:
value = va_arg(args, UPTRDIFF_T);
break;
default:
value = va_arg(args, unsigned int);
break;
}
fmtint(str, &len, size, value, base, width,
precision, flags);
break;
case 'c':
cvalue = va_arg(args, int);
OUTCHAR(str, len, size, cvalue);
break;
case 's':
strvalue = va_arg(args, char *);
fmtstr(str, &len, size, strvalue, width,
precision, flags);
break;
case 'p':
/*
* C99 says: "The value of the pointer is
* converted to a sequence of printing
* characters, in an implementation-defined
* manner." (C99: 7.19.6.1, 8)
*/
if ((strvalue = va_arg(args, void *)) == NULL)
/*
* We use the glibc format. BSD prints
* "0x0", SysV "0".
*/
fmtstr(str, &len, size, "(nil)", width,
-1, flags);
else {
/*
* We use the BSD/glibc format. SysV
* omits the "0x" prefix (which we emit
* using the PRINT_F_NUM flag).
*/
flags |= PRINT_F_NUM;
flags |= PRINT_F_UNSIGNED;
fmtint(str, &len, size,
(UINTPTR_T)strvalue, 16, width,
precision, flags);
}
break;
case 'n':
switch (cflags) {
case PRINT_C_CHAR:
charptr = va_arg(args, signed char *);
*charptr = len;
break;
case PRINT_C_SHORT:
shortptr = va_arg(args, short int *);
*shortptr = len;
break;
case PRINT_C_LONG:
longptr = va_arg(args, long int *);
*longptr = len;
break;
case PRINT_C_LLONG:
llongptr = va_arg(args, LLONG *);
*llongptr = len;
break;
case PRINT_C_SIZE:
/*
* C99 says that with the "z" length
* modifier, "a following `n' conversion
* specifier applies to a pointer to a
* signed integer type corresponding to
* size_t argument." (7.19.6.1, 7)
*/
sizeptr = va_arg(args, SSIZE_T *);
*sizeptr = len;
break;
case PRINT_C_INTMAX:
intmaxptr = va_arg(args, INTMAX_T *);
*intmaxptr = len;
break;
case PRINT_C_PTRDIFF:
ptrdiffptr = va_arg(args, PTRDIFF_T *);
*ptrdiffptr = len;
break;
default:
intptr = va_arg(args, int *);
*intptr = len;
break;
}
break;
case '%': /* Print a "%" character verbatim. */
OUTCHAR(str, len, size, ch);
break;
default: /* Skip other characters. */
break;
}
ch = *format++;
state = PRINT_S_DEFAULT;
base = cflags = flags = width = 0;
precision = -1;
break;
}
out:
if (len < size)
str[len] = '\0';
else if (size > 0)
str[size - 1] = '\0';
if (overflow || len >= INT_MAX) {
return -1;
}
return (int)len;
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}
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static void
fmtstr(char *str, size_t *len, size_t size, const char *value, int width,
int precision, int flags)
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{
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int padlen, strln; /* Amount to pad. */
int noprecision = (precision == -1);
if (value == NULL) /* We're forgiving. */
value = "(null)";
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/* If a precision was specified, don't read the string past it. */
for (strln = 0; value[strln] != '\0' &&
(noprecision || strln < precision); strln++)
continue;
if ((padlen = width - strln) < 0)
padlen = 0;
if (flags & PRINT_F_MINUS) /* Left justify. */
padlen = -padlen;
while (padlen > 0) { /* Leading spaces. */
OUTCHAR(str, *len, size, ' ');
padlen--;
}
while (*value != '\0' && (noprecision || precision-- > 0)) {
OUTCHAR(str, *len, size, *value);
value++;
}
while (padlen < 0) { /* Trailing spaces. */
OUTCHAR(str, *len, size, ' ');
padlen++;
}
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}
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static void
fmtint(char *str, size_t *len, size_t size, INTMAX_T value, int base, int width,
int precision, int flags)
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{
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UINTMAX_T uvalue;
char iconvert[MAX_CONVERT_LENGTH];
char sign = 0;
char hexprefix = 0;
int spadlen = 0; /* Amount to space pad. */
int zpadlen = 0; /* Amount to zero pad. */
int pos;
int separators = (flags & PRINT_F_QUOTE);
int noprecision = (precision == -1);
if (flags & PRINT_F_UNSIGNED)
uvalue = value;
else {
uvalue = (value >= 0) ? value : -value;
if (value < 0)
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sign = '-';
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else if (flags & PRINT_F_PLUS) /* Do a sign. */
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sign = '+';
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else if (flags & PRINT_F_SPACE)
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sign = ' ';
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}
pos = convert(uvalue, iconvert, sizeof(iconvert), base,
flags & PRINT_F_UP);
if (flags & PRINT_F_NUM && uvalue != 0) {
/*
* C99 says: "The result is converted to an `alternative form'.
* For `o' conversion, it increases the precision, if and only
* if necessary, to force the first digit of the result to be a
* zero (if the value and precision are both 0, a single 0 is
* printed). For `x' (or `X') conversion, a nonzero result has
* `0x' (or `0X') prefixed to it." (7.19.6.1, 6)
*/
switch (base) {
case 8:
if (precision <= pos)
precision = pos + 1;
break;
case 16:
hexprefix = (flags & PRINT_F_UP) ? 'X' : 'x';
break;
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}
}
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if (separators) /* Get the number of group separators we'll print. */
separators = getnumsep(pos);
zpadlen = precision - pos - separators;
spadlen = width /* Minimum field width. */
- separators /* Number of separators. */
- MAX(precision, pos) /* Number of integer digits. */
- ((sign != 0) ? 1 : 0) /* Will we print a sign? */
- ((hexprefix != 0) ? 2 : 0); /* Will we print a prefix? */
if (zpadlen < 0)
zpadlen = 0;
if (spadlen < 0)
spadlen = 0;
/*
* C99 says: "If the `0' and `-' flags both appear, the `0' flag is
* ignored. For `d', `i', `o', `u', `x', and `X' conversions, if a
* precision is specified, the `0' flag is ignored." (7.19.6.1, 6)
*/
if (flags & PRINT_F_MINUS) /* Left justify. */
spadlen = -spadlen;
else if (flags & PRINT_F_ZERO && noprecision) {
zpadlen += spadlen;
spadlen = 0;
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}
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while (spadlen > 0) { /* Leading spaces. */
OUTCHAR(str, *len, size, ' ');
spadlen--;
}
if (sign != 0) /* Sign. */
OUTCHAR(str, *len, size, sign);
if (hexprefix != 0) { /* A "0x" or "0X" prefix. */
OUTCHAR(str, *len, size, '0');
OUTCHAR(str, *len, size, hexprefix);
}
while (zpadlen > 0) { /* Leading zeros. */
OUTCHAR(str, *len, size, '0');
zpadlen--;
}
while (pos > 0) { /* The actual digits. */
pos--;
OUTCHAR(str, *len, size, iconvert[pos]);
if (separators > 0 && pos > 0 && pos % 3 == 0)
printsep(str, len, size);
}
while (spadlen < 0) { /* Trailing spaces. */
OUTCHAR(str, *len, size, ' ');
spadlen++;
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}
}
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static void
printsep(char *str, size_t *len, size_t size)
{
OUTCHAR(str, *len, size, ',');
}
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static int
getnumsep(int digits)
{
int separators = (digits - ((digits % 3 == 0) ? 1 : 0)) / 3;
return separators;
}
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static int
convert(UINTMAX_T value, char *buf, size_t size, int base, int caps)
{
const char *digits = caps ? "0123456789ABCDEF" : "0123456789abcdef";
size_t pos = 0;
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/* We return an unterminated buffer with the digits in reverse order. */
do {
buf[pos++] = digits[value % base];
value /= base;
} while (value != 0 && pos < size);
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return (int)pos;
}
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int vsprintf(char *buf, const char *fmt, va_list args)
{
return vsnprintf(buf, INT_MAX, fmt, args);
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}
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