utf8Strchr
Finds the leftmost occurrence of the given Unicode character in a UTF-8 encoded string, while limiting the search to @len bytes. If @len is -1, allow unbounded search.
Return
null if the string does not contain the character, otherwise, a pointer to the start of the leftmost occurrence of the character in the string.
Parameters
p
a nul-terminated UTF-8 encoded string
len
the maximum length of @p
c
a Unicode character