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#include <init/stdlib.h>
#include <shared/syscalls.h>
#include <stdarg.h>
int __tty_fd;
int memcmp(const void *s1, const void *s2, size_t n) {
const unsigned char *c1 = s1, *c2 = s2;
for (size_t i = 0; i < n; i++) {
if (c1[i] != c2[i]) {
if (c1[i] < c2[i]) return -1;
else return 1;
}
}
return 0;
}
int strcmp(const char *s1, const char *s2) {
while (*s1) {
if (*s1 != *s2) {
if (*s1 < *s2) return -1;
else return 1;
}
s1++; s2++;
}
return 0;
}
size_t strlen(const char *s) {
size_t c = 0;
while (*s++) c++;
return c;
}
int printf(const char *fmt, ...) {
const char *seg = fmt; // beginning of the current segment
int total = 0;
va_list argp;
va_start(argp, fmt);
for (;;) {
char c = *fmt++;
switch (c) {
case '\0':
// TODO don't assume that stdout is @ fd 0
_syscall_write(0, seg, fmt - seg - 1, 0);
return total + (fmt - seg - 1);
case '%':
_syscall_write(0, seg, fmt - seg - 1, 0);
total += fmt - seg - 1;
c = *fmt++;
switch (c) {
case 's':
const char *s = va_arg(argp, char*);
if (s) {
_syscall_write(0, s, strlen(s), 0);
total += strlen(s);
}
break;
case 'x':
unsigned int n = va_arg(argp, int);
size_t i = 4; // nibbles * 4
while (n >> i && i < (sizeof(int) * 8))
i += 4;
while (i > 0) {
i -= 4;
char h = '0' + ((n >> i) & 0xf);
if (h > '9') h += 'a' - '9' - 1;
_syscall_write(0, &h, 1, 0);
total++;
}
break;
}
seg = fmt;
break;
}
}
}
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