extern char *strstr(const char *str1, const char *str2);
extern size_t strcspn(const char *haystack, const char *reject);
extern size_t strspn(const char *haystack, const char *accept);
+extern char *strpbrk(const char *haystack, const char *accept);
extern char *strtok(char *str, const char *delim);
extern char *strtok_r(char *str, const char *delim, char **saveptr);