-void *memcpy(void *dest, const void *src, size_t len);
-void *memset(void *block, int count, size_t len);
-int memcmp(const void *b1, const void *b2, size_t len);
-size_t strlen(const char *s);
+ void *memcpy(void *dest, const void *src, size_t len);
+ void *memmove(void *dest, const void *src, size_t len);
+ int memcmp(const void *b1, const void *b2, size_t len);
+ void *memset(void *block, int count, size_t len);
+ size_t strnlen(const char *s, size_t n);
+ size_t strlen(const char *s);
+ char *strcpy(char *dest, const char *src);
+ char *strncpy(char *dest, const char *src, size_t len);
+ char *strcat(char *dest, const char *src);
+ char *strncat(char *dest, const char *src, size_t len);
+ int strcmp(const char *s1, const char *s2);
+ int strncmp(const char *s1, const char *s2, int n);