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#include <stdint.h>
#include "std.h"
void *memcpy(void *dest, const void *src, size_t n) {
// TODO align and copy 32 bits at a time
uint8_t *d = dest;
const uint8_t *s = src;
for (; n > 0; n--) {
*d++ = *s++;
}
return dest;
}
void *memmove(void *dest, const void *src, size_t n) {
if (src < dest && dest < src + n) {
// need to copy backwards
uint8_t *d = dest + n - 1;
const uint8_t *s = src + n - 1;
for (; n > 0; n--) {
*d-- = *s--;
}
return dest;
} else {
// can use normal memcpy
return memcpy(dest, src, n);
}
}
void *memset(void *s, int c, size_t n) {
uint8_t *s2 = s;
for (; n > 0; n--) {
*s2++ = c;
}
return s;
}
int memcmp(const char *s1, const char *s2, size_t n) {
while (n--) {
char c1 = *s1++;
char c2 = *s2++;
if (c1 < c2) return -1;
else if (c1 > c2) return 1;
}
return 0;
}
size_t strlen(const char *str) {
int len = 0;
for (const char *s = str; *s; s++) {
len += 1;
}
return len;
}
int strcmp(const char *s1, const char *s2) {
while (*s1 && *s2) {
char c1 = *s1++; // XXX UTF8 get char, next char
char c2 = *s2++; // XXX UTF8 get char, next char
if (c1 < c2) return -1;
else if (c1 > c2) return 1;
}
if (*s2) return -1;
else if (*s1) return 1;
else return 0;
}
int strncmp(const char *s1, const char *s2, size_t n) {
while (*s1 && *s2 && n > 0) {
char c1 = *s1++; // XXX UTF8 get char, next char
char c2 = *s2++; // XXX UTF8 get char, next char
n--;
if (c1 < c2) return -1;
else if (c1 > c2) return 1;
}
if (n == 0) return 0;
else if (*s2) return -1;
else if (*s1) return 1;
else return 0;
}
char *strcpy(char *dest, const char *src) {
char *d = dest;
while (*src) {
*d++ = *src++;
}
*d = '\0';
return dest;
}
// needed because gcc optimises strcpy + strcat to this
char *stpcpy(char *dest, const char *src) {
while (*src) {
*dest++ = *src++;
}
*dest = '\0';
return dest;
}
char *strcat(char *dest, const char *src) {
char *d = dest;
while (*d) {
d++;
}
while (*src) {
*d++ = *src++;
}
*d = '\0';
return dest;
}
// Public Domain implementation of strchr from:
// http://en.wikibooks.org/wiki/C_Programming/Strings#The_strchr_function
char *strchr(const char *s, int c)
{
/* Scan s for the character. When this loop is finished,
s will either point to the end of the string or the
character we were looking for. */
while (*s != '\0' && *s != (char)c)
s++;
return ((*s == c) ? (char *) s : 0);
}
// Public Domain implementation of strstr from:
// http://en.wikibooks.org/wiki/C_Programming/Strings#The_strstr_function
char *strstr(const char *haystack, const char *needle)
{
size_t needlelen;
/* Check for the null needle case. */
if (*needle == '\0')
return (char *) haystack;
needlelen = strlen(needle);
for (; (haystack = strchr(haystack, *needle)) != 0; haystack++)
if (strncmp(haystack, needle, needlelen) == 0)
return (char *) haystack;
return 0;
}
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