matos/core/klibc.c

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4.7 KiB
C
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#include "klibc.h"
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#include "serial.h"
#include "vga.h"
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int memcmp(const void *aptr, const void *bptr, size_t size)
{
const unsigned char *a = (const unsigned char *)aptr;
const unsigned char *b = (const unsigned char *)bptr;
for (size_t i = 0; i < size; i++) {
if (a[i] < b[i])
return -1;
else if (b[i] < a[i])
return 1;
}
return 0;
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}
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void *memcpy(void *dst, const void *src, size_t n)
{
char *dstChar = dst;
const char *srcChar = src;
for (size_t i = 0; i < n; i++) {
*(dstChar++) = *(srcChar++);
}
return dst;
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}
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void *memset(void *src, int c, size_t n)
{
for (char *ptr = (char *)src; n > 0; n--, ptr++) {
*ptr = (char)c;
}
return src;
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}
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char *itoa(int value, char *str, int base)
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{
char *rc;
char *ptr;
char *low;
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// Check for supported base.
if (base < 2 || base > 36) {
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*str = '\0';
return str;
}
rc = ptr = str;
// Set '-' for negative decimals.
if (value < 0 && base == 10) {
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*ptr++ = '-';
}
// Remember where the numbers start.
low = ptr;
// The actual conversion.
do {
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// Modulo is negative for negative value. This trick makes abs() unnecessary.
*ptr++ = "zyxwvutsrqponmlkjihgfedcba9876543210123456789abcdefghijklmnopqrstuvwxyz"
[35 + value % base];
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value /= base;
} while (value);
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// Terminating the string.
*ptr-- = '\0';
// Invert the numbers.
while (low < ptr) {
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char tmp = *low;
*low++ = *ptr;
*ptr-- = tmp;
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}
return rc;
}
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/* K&R */
void reverse(char s[])
{
int c, i, j;
for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
c = s[i];
s[i] = s[j];
s[j] = c;
}
}
/* K&R */
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int strlen(const char s[])
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{
int i = 0;
while (s[i] != '\0')
++i;
return i;
}
/* K&R
* Returns <0 if s1<s2, 0 if s1==s2, >0 if s1>s2 */
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int strcmp(const char s1[], const char s2[])
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{
int i;
for (i = 0; s1[i] == s2[i]; i++) {
if (s1[i] == '\0')
return 0;
}
return s1[i] - s2[i];
}
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unsigned int strnlen(const char *s, size_t count)
{
const char *sc;
for (sc = s; count-- && *sc != '\0'; ++sc)
/* nothing */ continue;
return sc - s;
}
char *strzcpy(register char *dst, register const char *src, register int len)
{
int i;
if (len <= 0)
return dst;
for (i = 0; i < len; i++) {
dst[i] = src[i];
if (src[i] == '\0')
return dst;
}
dst[len - 1] = '\0';
return dst;
}
void printf(const char *format, ...)
{
va_list ap;
va_start(ap, format);
vprintf(format, ap);
va_end(ap);
}
void puts(const char *str)
{
while (*str) {
putc(*(str++));
}
}
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void putc(const char str)
{
VGAputc(str);
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serialPutc(str);
}
void printInt(int integer)
{
char num[sizeof(int) * 3]; // int max is 2^(sizeof(int)*8) which is (2^3)^(sizeof(int)*8/3)
// = 8^(sizeof(int)*8/3) ~ 10^(sizeof(int)*8/3)
int i = 0, k = 0;
if (integer < 0) {
putc('-');
}
if (integer == 0) {
num[i++] = 0;
}
while (integer != 0) {
int digit = integer % 10;
num[i++] = (digit > 0) ? digit : -digit;
integer = integer / 10;
}
for (k = i - 1; k >= 0; k--) {
putc(num[k] + '0');
}
}
void vprintf(const char *format, va_list ap)
{
int i = 0;
while (format[i] != '\0') {
switch (format[i]) {
case '%':
switch (format[i + 1]) {
case 'i':
case 'd': {
int d = va_arg(ap, int);
printInt(d);
break;
}
case 'x': {
char val[sizeof(int) * 2];
int d = va_arg(ap, int);
itoa(d, val, 16);
puts(val);
break;
}
case 'c': {
int c = va_arg(ap, int);
putc((char)c);
break;
}
case 's': {
char *str = va_arg(ap, char *);
if (!str)
str = "[NULL STR]";
puts(str);
break;
}
case '%':
putc('%');
break;
}
i++;
break;
default:
putc(format[i]);
}
i++;
}
}