void *memset(void *dest, int c, int len);
int memcmp(const void *av, const void *bv, int len);
char *strncat(char *dest, const char *src, unsigned int n);
+char *strcat(char *dest, const char *src);
+void strreverse(char s[]);
+void itoa(int n, char s[]);
+
#endif /* __STRING_H */