Files
my-os-project2/kernel/hal/util.c

112 lines
2.2 KiB
C

#include <stdint.h>
#include <stddef.h>
#include "hal.h"
void *hal_memset(void *p, int c, size_t n) {
char *cp = p;
for (size_t i = 0; i < n; i++) cp[i] = c;
return p;
}
void *hal_memcpy(void *dst, const void *src, size_t n) {
char *a = dst;
const char *b = src;
for (size_t i = 0; i < n; i++) a[i] = b[i];
return dst;
}
size_t hal_strlen(char *s) {
char *s2;
for (s2 = s; *s2; ++s2);
return (s2 - s);
}
// https://aticleworld.com/memcmp-in-c/
int hal_memcmp(const void *s1, const void *s2, int len)
{
unsigned char *p = s1;
unsigned char *q = s2;
int charCompareStatus = 0;
//If both pointer pointing same memory block
if (s1 == s2)
{
return charCompareStatus;
}
while (len > 0)
{
if (*p != *q)
{ //compare the mismatching character
charCompareStatus = (*p >*q)?1:-1;
break;
}
len--;
p++;
q++;
}
return charCompareStatus;
}
int hal_strcmp(const char *a, const char *b) {
while (*a && (*a == *b)) {
a++, b++;
}
return (unsigned char)*a - (unsigned char)*b;
}
size_t hal_strcspn(const char *s, const char *reject) {
size_t count = 0;
for (; *s != '\0'; ++s) {
const char *r = reject;
while (*r != '\0') {
if (*s == *r) {
return count;
}
r++;
}
count++;
}
return count;
}
size_t hal_strspn(const char *s, const char *accept) {
size_t count = 0;
for (; *s != '\0'; ++s) {
const char *a = accept;
int matched = 0;
while (*a != '\0') {
if (*s == *a) {
matched = 1;
break;
}
a++;
}
if (!matched) {
return count;
}
count++;
}
return count;
}
char *hal_strcpy(char *dest, const char *src) {
char *d = dest;
while ((*d++ = *src++) != '\0') {
;
}
return dest;
}
char *hal_strchr(const char *s, int c) {
char ch = (char)c;
while (*s != '\0') {
if (*s == ch) {
return (char *)s;
}
s++;
}
if (ch == '\0') {
return (char *)s;
}
return NULL;
}