char * strpbrk_P(const char *__s, const char *__accept) __ATTR_PURE__
The strpbrk_P() function locates the first occurrence in the string s of any of the characters in the flash string accept. This function is similar to strpbrk() except that accept is a pointer to a string in program space.
The strpbrk_P() 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.