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solanum-vs-hackint-and-char.../libratbox/src/snprintf.c

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/*
* Modified and hacked into libratbox by Aaron Sethman <androsyn@ratbox.org>
* The original headers are below..
* Note that this implementation does not process floating point numbers so
* you will likely need to fall back to using sprintf yourself to do those...
* $Id: snprintf.c 26092 2008-09-19 15:13:52Z androsyn $
*/
/*
* linux/lib/vsprintf.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
/*
* Wirzenius wrote this portably, Torvalds fucked it up :-)
*/
/*
* Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
* - changed to provide snprintf and vsnprintf functions
* So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
* - scnprintf and vscnprintf
*/
#include <libratbox_config.h>
#include <ratbox_lib.h>
static int
skip_atoi(const char **s)
{
int i = 0;
while(isdigit(**s))
i = i * 10 + *((*s)++) - '0';
return i;
}
/* Decimal conversion is by far the most typical, and is used
* for /proc and /sys data. This directly impacts e.g. top performance
* with many processes running. We optimize it for speed
* using code from
* http://www.cs.uiowa.edu/~jones/bcd/decimal.html
* (with permission from the author, Douglas W. Jones). */
/* Formats correctly any integer in [0,99999].
* Outputs from one to five digits depending on input.
* On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
static char *
put_dec_trunc(char *buf, unsigned q)
{
unsigned d3, d2, d1, d0;
d1 = (q >> 4) & 0xf;
d2 = (q >> 8) & 0xf;
d3 = (q >> 12);
d0 = 6 * (d3 + d2 + d1) + (q & 0xf);
q = (d0 * 0xcd) >> 11;
d0 = d0 - 10 * q;
*buf++ = d0 + '0'; /* least significant digit */
d1 = q + 9 * d3 + 5 * d2 + d1;
if(d1 != 0)
{
q = (d1 * 0xcd) >> 11;
d1 = d1 - 10 * q;
*buf++ = d1 + '0'; /* next digit */
d2 = q + 2 * d2;
if((d2 != 0) || (d3 != 0))
{
q = (d2 * 0xd) >> 7;
d2 = d2 - 10 * q;
*buf++ = d2 + '0'; /* next digit */
d3 = q + 4 * d3;
if(d3 != 0)
{
q = (d3 * 0xcd) >> 11;
d3 = d3 - 10 * q;
*buf++ = d3 + '0'; /* next digit */
if(q != 0)
*buf++ = q + '0'; /* most sign. digit */
}
}
}
return buf;
}
/* Same with if's removed. Always emits five digits */
static char *
put_dec_full(char *buf, unsigned q)
{
/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
/* but anyway, gcc produces better code with full-sized ints */
unsigned d3, d2, d1, d0;
d1 = (q >> 4) & 0xf;
d2 = (q >> 8) & 0xf;
d3 = (q >> 12);
/* Possible ways to approx. divide by 10 */
/* gcc -O2 replaces multiply with shifts and adds */
// (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
// (x * 0x67) >> 10: 1100111
// (x * 0x34) >> 9: 110100 - same
// (x * 0x1a) >> 8: 11010 - same
// (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
d0 = 6 * (d3 + d2 + d1) + (q & 0xf);
q = (d0 * 0xcd) >> 11;
d0 = d0 - 10 * q;
*buf++ = d0 + '0';
d1 = q + 9 * d3 + 5 * d2 + d1;
q = (d1 * 0xcd) >> 11;
d1 = d1 - 10 * q;
*buf++ = d1 + '0';
d2 = q + 2 * d2;
q = (d2 * 0xd) >> 7;
d2 = d2 - 10 * q;
*buf++ = d2 + '0';
d3 = q + 4 * d3;
q = (d3 * 0xcd) >> 11; /* - shorter code */
/* q = (d3 * 0x67) >> 10; - would also work */
d3 = d3 - 10 * q;
*buf++ = d3 + '0';
*buf++ = q + '0';
return buf;
}
static char *
put_dec(char *buf, unsigned long long int num)
{
while(1)
{
unsigned rem;
if(num < 100000)
return put_dec_trunc(buf, num);
rem = num % 100000;
num = num / 100000;
buf = put_dec_full(buf, rem);
}
}
#define ZEROPAD 1 /* pad with zero */
#define SIGN 2 /* unsigned/signed long */
#define PLUS 4 /* show plus */
#define SPACE 8 /* space if plus */
#define LEFT 16 /* left justified */
#define SPECIAL 32 /* 0x */
#define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */
static char *
number(char *buf, char *end, unsigned long long int num, int base, int size, int precision,
int type)
{
char sign, tmp[66];
const char *digits;
/* we are called with base 8, 10 or 16, only, thus don't need "g..." */
static const char small_digits[] = "0123456789abcdefx"; /* "ghijklmnopqrstuvwxyz"; */
static const char large_digits[] = "0123456789ABCDEFX"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
int need_pfx = ((type & SPECIAL) && base != 10);
int i;
digits = (type & LARGE) ? large_digits : small_digits;
if(type & LEFT)
type &= ~ZEROPAD;
if(base < 2 || base > 36)
return NULL;
sign = 0;
if(type & SIGN)
{
if((signed long long int)num < 0)
{
sign = '-';
num = -(signed long long int)num;
size--;
}
else if(type & PLUS)
{
sign = '+';
size--;
}
else if(type & SPACE)
{
sign = ' ';
size--;
}
}
if(need_pfx)
{
size--;
if(base == 16)
size--;
}
/* generate full string in tmp[], in reverse order */
i = 0;
if(num == 0)
tmp[i++] = '0';
/* Generic code, for any base:
else do {
tmp[i++] = digits[do_div(num,base)];
} while (num != 0);
*/
else if(base != 10)
{ /* 8 or 16 */
int mask = base - 1;
int shift = 3;
if(base == 16)
shift = 4;
do
{
tmp[i++] = digits[((unsigned char)num) & mask];
num >>= shift;
}
while(num);
}
else
{ /* base 10 */
i = put_dec(tmp, num) - tmp;
}
/* printing 100 using %2d gives "100", not "00" */
if(i > precision)
precision = i;
/* leading space padding */
size -= precision;
if(!(type & (ZEROPAD + LEFT)))
{
while(--size >= 0)
{
if(buf < end)
*buf = ' ';
++buf;
}
}
/* sign */
if(sign)
{
if(buf < end)
*buf = sign;
++buf;
}
/* "0x" / "0" prefix */
if(need_pfx)
{
if(buf < end)
*buf = '0';
++buf;
if(base == 16)
{
if(buf < end)
*buf = digits[16]; /* for arbitrary base: digits[33]; */
++buf;
}
}
/* zero or space padding */
if(!(type & LEFT))
{
char c = (type & ZEROPAD) ? '0' : ' ';
while(--size >= 0)
{
if(buf < end)
*buf = c;
++buf;
}
}
/* hmm even more zero padding? */
while(i <= --precision)
{
if(buf < end)
*buf = '0';
++buf;
}
/* actual digits of result */
while(--i >= 0)
{
if(buf < end)
*buf = tmp[i];
++buf;
}
/* trailing space padding */
while(--size >= 0)
{
if(buf < end)
*buf = ' ';
++buf;
}
return buf;
}
/**
* vsnprintf - Format a string and place it in a buffer
* @buf: The buffer to place the result into
* @size: The size of the buffer, including the trailing null space
* @fmt: The format string to use
* @args: Arguments for the format string
*
* The return value is the number of characters which would
* be generated for the given input, excluding the trailing
* '\0', as per ISO C99. If you want to have the exact
* number of characters written into @buf as return value
* (not including the trailing '\0'), use vscnprintf(). If the
* return is greater than or equal to @size, the resulting
* string is truncated.
*
* Call this function if you are already dealing with a va_list.
* You probably want snprintf() instead.
*/
int
rb_vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
int len;
unsigned long long int num;
int i, base;
char *str, *end, c;
const char *s;
int flags; /* flags to number() */
int field_width; /* width of output field */
int precision; /* min. # of digits for integers; max
number of chars for from string */
int qualifier; /* 'h', 'l', or 'L' for integer fields */
/* 'z' support added 23/7/1999 S.H. */
/* 'z' changed to 'Z' --davidm 1/25/99 */
/* 't' added for ptrdiff_t */
/* Reject out-of-range values early. Large positive sizes are
used for unknown buffer sizes. */
if(rb_unlikely((int)size < 0))
{
return 0;
}
str = buf;
end = buf + size;
/* Make sure end is always >= buf */
if(end < buf)
{
end = ((void *)-1);
size = end - buf;
}
for(; *fmt; ++fmt)
{
if(*fmt != '%')
{
if(str < end)
*str = *fmt;
++str;
continue;
}
/* process flags */
flags = 0;
repeat:
++fmt; /* this also skips first '%' */
switch (*fmt)
{
case '-':
flags |= LEFT;
goto repeat;
case '+':
flags |= PLUS;
goto repeat;
case ' ':
flags |= SPACE;
goto repeat;
case '#':
flags |= SPECIAL;
goto repeat;
case '0':
flags |= ZEROPAD;
goto repeat;
}
/* get field width */
field_width = -1;
if(isdigit(*fmt))
field_width = skip_atoi(&fmt);
else if(*fmt == '*')
{
++fmt;
/* it's the next argument */
field_width = va_arg(args, int);
if(field_width < 0)
{
field_width = -field_width;
flags |= LEFT;
}
}
/* get the precision */
precision = -1;
if(*fmt == '.')
{
++fmt;
if(isdigit(*fmt))
precision = skip_atoi(&fmt);
else if(*fmt == '*')
{
++fmt;
/* it's the next argument */
precision = va_arg(args, int);
}
if(precision < 0)
precision = 0;
}
/* get the conversion qualifier */
qualifier = -1;
if(*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
*fmt == 'Z' || *fmt == 'z' || *fmt == 't')
{
qualifier = *fmt;
++fmt;
if(qualifier == 'l' && *fmt == 'l')
{
qualifier = 'L';
++fmt;
}
}
/* default base */
base = 10;
switch (*fmt)
{
case 'c':
if(!(flags & LEFT))
{
while(--field_width > 0)
{
if(str < end)
*str = ' ';
++str;
}
}
c = (unsigned char)va_arg(args, int);
if(str < end)
*str = c;
++str;
while(--field_width > 0)
{
if(str < end)
*str = ' ';
++str;
}
continue;
case 's':
s = va_arg(args, char *);
if(s == NULL)
{
abort(); /* prefer blowing up vs corrupt data */
}
len = rb_strnlen(s, precision);
if(!(flags & LEFT))
{
while(len < field_width--)
{
if(str < end)
*str = ' ';
++str;
}
}
for(i = 0; i < len; ++i)
{
if(str < end)
*str = *s;
++str;
++s;
}
while(len < field_width--)
{
if(str < end)
*str = ' ';
++str;
}
continue;
case 'p':
if(field_width == -1)
{
field_width = 2 * sizeof(void *);
flags |= ZEROPAD;
}
str = number(str, end,
(unsigned long)va_arg(args, void *),
16, field_width, precision, flags);
continue;
case 'n':
/* FIXME:
* What does C99 say about the overflow case here? */
if(qualifier == 'l')
{
long *ip = va_arg(args, long *);
*ip = (str - buf);
}
else if(qualifier == 'Z' || qualifier == 'z')
{
size_t *ip = va_arg(args, size_t *);
*ip = (str - buf);
}
else
{
int *ip = va_arg(args, int *);
*ip = (str - buf);
}
continue;
case '%':
if(str < end)
*str = '%';
++str;
continue;
/* integer number formats - set up the flags and "break" */
case 'o':
base = 8;
break;
case 'X':
flags |= LARGE;
case 'x':
base = 16;
break;
case 'd':
case 'i':
flags |= SIGN;
case 'u':
break;
default:
if(str < end)
*str = '%';
++str;
if(*fmt)
{
if(str < end)
*str = *fmt;
++str;
}
else
{
--fmt;
}
continue;
}
if(qualifier == 'L')
num = va_arg(args, long long int);
else if(qualifier == 'l')
{
num = va_arg(args, unsigned long);
if(flags & SIGN)
num = (signed long)num;
}
else if(qualifier == 'Z' || qualifier == 'z')
{
num = va_arg(args, size_t);
}
else if(qualifier == 't')
{
num = va_arg(args, ptrdiff_t);
}
else if(qualifier == 'h')
{
num = (unsigned short)va_arg(args, int);
if(flags & SIGN)
num = (signed short)num;
}
else
{
num = va_arg(args, unsigned int);
if(flags & SIGN)
num = (signed int)num;
}
str = number(str, end, num, base, field_width, precision, flags);
}
if(size > 0)
{
if(str < end)
*str = '\0';
else
end[-1] = '\0';
}
/* the trailing null byte doesn't count towards the total */
return str - buf;
}
/**
* snprintf - Format a string and place it in a buffer
* @buf: The buffer to place the result into
* @size: The size of the buffer, including the trailing null space
* @fmt: The format string to use
* @...: Arguments for the format string
*
* The return value is the number of characters which would be
* generated for the given input, excluding the trailing null,
* as per ISO C99. If the return is greater than or equal to
* @size, the resulting string is truncated.
*/
int
rb_snprintf(char *buf, size_t size, const char *fmt, ...)
{
va_list args;
int i;
va_start(args, fmt);
i = rb_vsnprintf(buf, size, fmt, args);
va_end(args);
return i;
}
/**
* vsprintf - Format a string and place it in a buffer
* @buf: The buffer to place the result into
* @fmt: The format string to use
* @args: Arguments for the format string
*
* The function returns the number of characters written
* into @buf. Use vsnprintf() or vscnprintf() in order to avoid
* buffer overflows.
*
* Call this function if you are already dealing with a va_list.
* You probably want sprintf() instead.
*/
int
rb_vsprintf(char *buf, const char *fmt, va_list args)
{
return rb_vsnprintf(buf, INT_MAX, fmt, args);
}
/**
* sprintf - Format a string and place it in a buffer
* @buf: The buffer to place the result into
* @fmt: The format string to use
* @...: Arguments for the format string
*
* The function returns the number of characters written
* into @buf. Use snprintf() or scnprintf() in order to avoid
* buffer overflows.
*/
int
rb_sprintf(char *buf, const char *fmt, ...)
{
va_list args;
int i;
va_start(args, fmt);
i = rb_vsnprintf(buf, INT_MAX, fmt, args);
va_end(args);
return i;
}
/*
* rb_vsprintf_append()
* appends sprintf formatted string to the end of the buffer
*/
int
rb_vsprintf_append(char *str, const char *format, va_list ap)
{
size_t x = strlen(str);
return (rb_vsprintf(str + x, format, ap) + x);
}
/*
* rb_sprintf_append()
* appends sprintf formatted string to the end of the buffer
*/
int
rb_sprintf_append(char *str, const char *format, ...)
{
int x;
va_list ap;
va_start(ap, format);
x = rb_vsprintf_append(str, format, ap);
va_end(ap);
return (x);
}
/*
* rb_vsnprintf_append()
* appends sprintf formatted string to the end of the buffer but not
* exceeding len
*/
int
rb_vsnprintf_append(char *str, size_t len, const char *format, va_list ap)
{
size_t x;
if(len == 0)
return 0;
x = strlen(str);
if(len < x)
{
str[len - 1] = '\0';
return len - 1;
}
return (rb_vsnprintf(str + x, len - x, format, ap) + x);
}
/*
* rb_snprintf_append()
* appends snprintf formatted string to the end of the buffer but not
* exceeding len
*/
int
rb_snprintf_append(char *str, size_t len, const char *format, ...)
{
int x;
va_list ap;
va_start(ap, format);
x = rb_vsnprintf_append(str, len, format, ap);
va_end(ap);
return (x);
}
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