#include "stddef.h"

void * memcpy(void *s1, const void *s2, size_t n);
void * mempcpy(void *s1, const void *s2, size_t n);
void * memmove(void *s1, const void *s2, size_t n);
void * memset(void *b, int c, size_t n);

int memcmp(const void *s1, const void *s2, size_t n);

int strcmp(const char *s1, const char *s2);
int strncmp(const char *s1, const char *s2, size_t n);

char * strcpy(char *s1, const char *s2);
char * strncpy(char *s1, const char *s2, size_t n);

size_t strlen(const char *);
char * strchr(const char *, int);
char * strrchr(const char *, int);

char * strdup(const char *);