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#include <stdlib.h>
#include <ctype.h>
#include <stdarg.h>
#include <stdint.h>
#include <string.h>
extern char *itoa(int, char *, int);
void _exit(int code)
{
(void)code;
for (;;);
}
char *snprintf(char *buf, unsigned int max, const char *format, ...)
{
va_list args;
va_start(args, format);
if (buf == 0 || max == 0)
return 0;
static char nbuf[32];
unsigned int off = 0;
for (unsigned int i = 0; format[i] != '\0' && off < max; i++) {
if (format[i] == '%') {
i++;
nbuf[0] = '\0';
switch (format[i]) {
case 'd':
itoa(va_arg(args, int), nbuf, 10);
break;
case 'u':
itoa(va_arg(args, unsigned int), nbuf, 10);
break;
case 'x':
case 'p':
itoa(va_arg(args, unsigned int), nbuf, 16);
break;
case 'f':
itoa((int)va_arg(args, double), nbuf, 10);
continue;
break;
default:
buf[off++] = format[i];
nbuf[0] = '\0';
break;
}
if (nbuf[0] != '\0') {
for (unsigned int j = 0; off < max && j < 32 &&
nbuf[j] != '\0'; off++, j++)
buf[off] = nbuf[j];
}
} else {
buf[off++] = format[i];
}
}
buf[off >= max ? max - 1 : off] = '\0';
va_end(args);
return buf;
}
float strtof(const char *s, char **endptr)
{
(void)s;
(void)endptr;
float res = 0.0f;
char neg = 0;
unsigned int i = 0;
if (s[0] == '-') {
neg = 1;
i++;
}
for (; isdigit(s[i]); i++) {
res *= 10.0f;
res += (s[i] - '0');
}
if (s[i] != '.')
goto end;
float div = 0.1f;
for (i++; isdigit(s[i]); i++) {
res += div * (s[i] - '0');
div /= 10.0f;
}
end:
return (neg == 0) ? res : -res;
}
int atoi(const char *s)
{
unsigned int i = 0;
char neg = 0;
int n = 0;
if (s[0] == '-') {
neg = 1;
i = 1;
}
for (; isdigit(s[i]); i++) {
n *= 10;
n += s[i] - '0';
}
return (neg == 0) ? n : -n;
}
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