#include <ctype.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <sys/types.h>
#ifndef SCOPE
#define SCOPE
#endif
#ifndef WIDE_INT
#define WIDE_INT long
#endif
typedef WIDE_INT wide_int;
typedef unsigned WIDE_INT u_wide_int;
typedef int bool_int;
#ifndef FALSE
#define FALSE 0
#define TRUE 1
#endif
#define NUL '\0'
#define S_NULL "(null)"
#define S_NULL_LEN 6
#define FLOAT_DIGITS 6
#define EXPONENT_LENGTH 10
typedef enum { NO = 0, YES = 1 } boolean_e ;
#define NUM_BUF_SIZE 512
#define INS_CHAR( c, sp, bep, cc ) \
{ \
if ( sp < bep ) \
*sp++ = c ; \
cc++ ; \
}
#define NUM( c ) ( c - '0' )
#define STR_TO_DEC( str, num ) \
num = NUM( *str++ ) ; \
while ( isdigit( *str ) ) { \
num *= 10 ; \
num += NUM( *str++ ) ; \
}
#define FIX_PRECISION( adjust, precision, s, s_len ) \
if ( adjust ) \
while ( s_len < precision ) { \
*--s = '0' ; \
s_len++ ; \
}
#define PAD( width, len, ch ) \
do { \
INS_CHAR( ch, sp, bep, cc ) ; \
width-- ; \
} while ( width > len )
#define PREFIX( str, length, ch ) \
*--str = ch ; length++ ; has_prefix = YES
static char *conv_10(wide_int num, bool_int is_unsigned,
bool_int * is_negative, char *buf_end, int *len);
SCOPE int vsnprintf(char *str, size_t size, const char *fmt, va_list ap);
SCOPE int
snprintf(char *str, size_t size, const char *fmt, ...)
{
int cc;
va_list ap;
va_start(ap, fmt);
cc = vsnprintf(str, size, fmt, ap);
va_end(ap);
return cc;
}
static char *
conv_fp(char format, double num, boolean_e add_dp, int precision,
bool_int *is_negative, char buf[], int *len)
{
char *s = buf;
char *p;
int decimal_point;
if (format == 'f')
p = fcvt(num, precision, &decimal_point, is_negative);
else
p = ecvt(num, precision + 1, &decimal_point, is_negative);
if (isalpha(*p)) {
*len = strlen(strcpy(buf, p));
*is_negative = FALSE;
return (buf);
}
if (format == 'f')
if (decimal_point <= 0) {
*s++ = '0';
if (precision > 0) {
*s++ = '.';
while (decimal_point++ < 0)
*s++ = '0';
} else if (add_dp)
*s++ = '.';
} else {
while (decimal_point-- > 0)
*s++ = *p++;
if (precision > 0 || add_dp)
*s++ = '.';
} else {
*s++ = *p++;
if (precision > 0 || add_dp)
*s++ = '.';
}
while (*p)
*s++ = *p++;
if (format != 'f') {
char temp[EXPONENT_LENGTH];
int t_len;
bool_int exponent_is_negative;
*s++ = format;
decimal_point--;
if (decimal_point != 0) {
p = conv_10((wide_int) decimal_point, FALSE, &exponent_is_negative,
&temp[EXPONENT_LENGTH], &t_len);
*s++ = exponent_is_negative ? '-' : '+';
if (t_len == 1)
*s++ = '0';
while (t_len--)
*s++ = *p++;
} else {
*s++ = '+';
*s++ = '0';
*s++ = '0';
}
}
*len = s - buf;
return (buf);
}
static char *
conv_p2(u_wide_int num, int nbits, char format, char *buf_end, int *len)
{
int mask = (1 << nbits) - 1;
char *p = buf_end;
static char low_digits[] = "0123456789abcdef";
static char upper_digits[] = "0123456789ABCDEF";
char *digits = (format == 'X') ? upper_digits : low_digits;
do {
*--p = digits[num & mask];
num >>= nbits;
}
while (num);
*len = buf_end - p;
return (p);
}
static char *
conv_10(wide_int num, bool_int is_unsigned, bool_int *is_negative,
char *buf_end, int *len)
{
char *p = buf_end;
u_wide_int magnitude;
if (is_unsigned) {
magnitude = (u_wide_int) num;
*is_negative = FALSE;
} else {
*is_negative = (num < 0);
if (*is_negative) {
wide_int t = num + 1;
magnitude = ((u_wide_int) - t) + 1;
} else
magnitude = (u_wide_int) num;
}
do {
register u_wide_int new_magnitude = magnitude / 10;
*--p = magnitude - new_magnitude * 10 + '0';
magnitude = new_magnitude;
}
while (magnitude);
*len = buf_end - p;
return (p);
}
SCOPE int
vsnprintf(char *str, size_t size, const char *fmt, va_list ap)
{
char *sp;
char *bep;
int cc = 0;
int i;
char *s;
char *q;
int s_len;
int min_width;
int precision;
enum {
LEFT, RIGHT
} adjust;
char pad_char;
char prefix_char;
double fp_num;
wide_int i_num;
u_wide_int ui_num;
char num_buf[NUM_BUF_SIZE];
char char_buf[2];
boolean_e is_long;
boolean_e alternate_form;
boolean_e print_sign;
boolean_e print_blank;
boolean_e adjust_precision;
boolean_e adjust_width;
bool_int is_negative;
if (size == 0)
return 0;
sp = str;
bep = str + size - 1;
while (*fmt) {
if (*fmt != '%') {
INS_CHAR(*fmt, sp, bep, cc);
} else {
adjust = RIGHT;
alternate_form = print_sign = print_blank = NO;
pad_char = ' ';
prefix_char = NUL;
fmt++;
if (isascii(*fmt) && !islower(*fmt)) {
for (;; fmt++) {
if (*fmt == '-')
adjust = LEFT;
else if (*fmt == '+')
print_sign = YES;
else if (*fmt == '#')
alternate_form = YES;
else if (*fmt == ' ')
print_blank = YES;
else if (*fmt == '0')
pad_char = '0';
else
break;
}
if (isdigit(*fmt)) {
STR_TO_DEC(fmt, min_width);
adjust_width = YES;
} else if (*fmt == '*') {
min_width = va_arg(ap, int);
fmt++;
adjust_width = YES;
if (min_width < 0) {
adjust = LEFT;
min_width = -min_width;
}
} else
adjust_width = NO;
if (*fmt == '.') {
adjust_precision = YES;
fmt++;
if (isdigit(*fmt)) {
STR_TO_DEC(fmt, precision);
} else if (*fmt == '*') {
precision = va_arg(ap, int);
fmt++;
if (precision < 0)
precision = 0;
} else
precision = 0;
} else
adjust_precision = NO;
} else
adjust_precision = adjust_width = NO;
if (*fmt == 'l') {
is_long = YES;
fmt++;
} else
is_long = NO;
switch (*fmt) {
case 'd':
case 'i':
case 'u':
if (is_long)
i_num = va_arg(ap, wide_int);
else
i_num = (wide_int) va_arg(ap, int);
s = conv_10(i_num, (*fmt) == 'u', &is_negative,
&num_buf[NUM_BUF_SIZE], &s_len);
FIX_PRECISION(adjust_precision, precision, s, s_len);
if (*fmt != 'u') {
if (is_negative)
prefix_char = '-';
else if (print_sign)
prefix_char = '+';
else if (print_blank)
prefix_char = ' ';
}
break;
case 'o':
if (is_long)
ui_num = va_arg(ap, u_wide_int);
else
ui_num = (u_wide_int) va_arg(ap, unsigned int);
s = conv_p2(ui_num, 3, *fmt,
&num_buf[NUM_BUF_SIZE], &s_len);
FIX_PRECISION(adjust_precision, precision, s, s_len);
if (alternate_form && *s != '0') {
*--s = '0';
s_len++;
}
break;
case 'x':
case 'X':
if (is_long)
ui_num = (u_wide_int) va_arg(ap, u_wide_int);
else
ui_num = (u_wide_int) va_arg(ap, unsigned int);
s = conv_p2(ui_num, 4, *fmt,
&num_buf[NUM_BUF_SIZE], &s_len);
FIX_PRECISION(adjust_precision, precision, s, s_len);
if (alternate_form && i_num != 0) {
*--s = *fmt;
*--s = '0';
s_len += 2;
}
break;
case 's':
s = va_arg(ap, char *);
if (s != NULL) {
s_len = strlen(s);
if (adjust_precision && precision < s_len)
s_len = precision;
} else {
s = S_NULL;
s_len = S_NULL_LEN;
}
pad_char = ' ';
break;
case 'f':
case 'e':
case 'E':
fp_num = va_arg(ap, double);
s = conv_fp(*fmt, fp_num, alternate_form,
(adjust_precision == NO) ? FLOAT_DIGITS : precision,
&is_negative, &num_buf[1], &s_len);
if (is_negative)
prefix_char = '-';
else if (print_sign)
prefix_char = '+';
else if (print_blank)
prefix_char = ' ';
break;
case 'g':
case 'G':
if (adjust_precision == NO)
precision = FLOAT_DIGITS;
else if (precision == 0)
precision = 1;
s = gcvt(va_arg(ap, double), precision, &num_buf[1]);
if (*s == '-')
prefix_char = *s++;
else if (print_sign)
prefix_char = '+';
else if (print_blank)
prefix_char = ' ';
s_len = strlen(s);
if (alternate_form && (q = strchr(s, '.')) == NULL)
s[s_len++] = '.';
if (*fmt == 'G' && (q = strchr(s, 'e')) != NULL)
*q = 'E';
break;
case 'c':
char_buf[0] = (char)(va_arg(ap, int));
s = &char_buf[0];
s_len = 1;
pad_char = ' ';
break;
case '%':
char_buf[0] = '%';
s = &char_buf[0];
s_len = 1;
pad_char = ' ';
break;
case 'n':
*(va_arg(ap, int *)) = cc;
break;
case 'p':
ui_num = (u_wide_int) va_arg(ap, void *);
if (sizeof(void *) <= sizeof(u_wide_int))
s = conv_p2(ui_num, 4, 'x',
&num_buf[NUM_BUF_SIZE], &s_len);
else {
s = "%p";
s_len = 2;
}
pad_char = ' ';
break;
case NUL:
continue;
default:
char_buf[0] = '%';
char_buf[1] = *fmt;
s = char_buf;
s_len = 2;
pad_char = ' ';
break;
}
if (prefix_char != NUL) {
*--s = prefix_char;
s_len++;
}
if (adjust_width && adjust == RIGHT && min_width > s_len) {
if (pad_char == '0' && prefix_char != NUL) {
INS_CHAR(*s, sp, bep, cc)
s++;
s_len--;
min_width--;
}
PAD(min_width, s_len, pad_char);
}
for (i = s_len; i != 0; i--) {
INS_CHAR(*s, sp, bep, cc);
s++;
}
if (adjust_width && adjust == LEFT && min_width > s_len)
PAD(min_width, s_len, pad_char);
}
fmt++;
}
if (cc < size)
str[cc] = NUL;
else
str[size - 1] = NUL;
return cc;
}