char * strpbrk(const char *__s, const char *__accept) __ATTR_PURE__
The strpbrk() function locates the first occurrence in the string
s of any of the characters in the string
accept.
The strpbrk() function returns a pointer to the character in
s that matches one of the characters in
accept, or NULL
if no such character is found. The terminating zero is not considered as a part of
string: if one or both args are empty, the result will
NULL.