Synopsis
size_t mbrlen_l(const char *s,
                size_t n,
                mbstate_t *ps,
                locale_t loc);
Note

mbrlen_l function is equivalent to the call:

mbrtowc_l(NULL, s, n, ps != NULL ? ps : &internal, loc); 

where internal is the mbstate_t object for the mbrlen function, except that the expression designated by ps is evaluated only once.