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#include <stdarg.h>
#include <limits.h>
#include <stdint.h>
#include <purgatory.h>
#include <string.h>
/*
* Output
* =============================================================================
*/
#define LONG_LONG_SHIFT ((int)((sizeof(unsigned long long)*CHAR_BIT) - 4))
#define LONG_SHIFT ((int)((sizeof(unsigned long)*CHAR_BIT) - 4))
#define INT_SHIFT ((int)((sizeof(unsigned int)*CHAR_BIT) - 4))
#define SHRT_SHIFT ((int)((sizeof(unsigned short)*CHAR_BIT) - 4))
#define CHAR_SHIFT ((int)((sizeof(unsigned char)*CHAR_BIT) - 4))
/**************************************************************************
PRINTF and friends
Formats:
%x - 4 bytes int (8 hex digits, lower case)
%X - 4 bytes int (8 hex digits, upper case)
%lx - 8 bytes long (16 hex digits, lower case)
%lX - 8 bytes long (16 hex digits, upper case)
%hx - 2 bytes int (4 hex digits, lower case)
%hX - 2 bytes int (4 hex digits, upper case)
%hhx - 1 byte int (2 hex digits, lower case)
%hhX - 1 byte int (2 hex digits, upper case)
- optional # prefixes 0x or 0X
%d - decimal int
%c - char
%s - string
Note: width specification not supported
**************************************************************************/
void printf(const char *fmt, ...)
{
va_list args;
char *p;
va_start(args, fmt);
for ( ; *fmt != '\0'; ++fmt) {
if (*fmt != '%') {
putchar(*fmt);
continue;
}
if (*++fmt == 's') {
for(p = va_arg(args, char *); *p != '\0'; p++)
putchar(*p);
}
else { /* Length of item is bounded */
char tmp[40], *q = tmp;
int shift = INT_SHIFT;
if (*fmt == 'L') {
shift = LONG_LONG_SHIFT;
fmt++;
}
else if (*fmt == 'l') {
shift = LONG_SHIFT;
fmt++;
}
else if (*fmt == 'h') {
shift = SHRT_SHIFT;
fmt++;
if (*fmt == 'h') {
shift = CHAR_SHIFT;
fmt++;
}
}
/*
* Before each format q points to tmp buffer
* After each format q points past end of item
*/
if ((*fmt | 0x20) == 'x') {
/* With x86 gcc, sizeof(long) == sizeof(int) */
unsigned long long h;
int ncase;
if (shift > LONG_SHIFT) {
h = va_arg(args, unsigned long long);
}
else if (shift > INT_SHIFT) {
h = va_arg(args, unsigned long);
} else {
h = va_arg(args, unsigned int);
}
ncase = (*fmt & 0x20);
for ( ; shift >= 0; shift -= 4)
*q++ = "0123456789ABCDEF"[(h >> shift) & 0xF] | ncase;
}
else if (*fmt == 'd') {
char *r;
long i;
if (shift > LONG_SHIFT) {
i = va_arg(args, long long);
}
else if (shift > INT_SHIFT) {
i = va_arg(args, long);
} else {
i = va_arg(args, int);
}
if (i < 0) {
*q++ = '-';
i = -i;
}
p = q; /* save beginning of digits */
do {
*q++ = '0' + (i % 10);
i /= 10;
} while (i);
/* reverse digits, stop in middle */
r = q; /* don't alter q */
while (--r > p) {
i = *r;
*r = *p;
*p++ = i;
}
}
else if (*fmt == 'c')
*q++ = va_arg(args, int);
else
*q++ = *fmt;
/* now output the saved string */
for (p = tmp; p < q; ++p)
putchar(*p);
}
}
va_end(args);
}
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