MBRLEN(3) BSD Library Functions Manual MBRLEN(3)
mbrlen -- get number of bytes in a character (restartable)
Standard C Library (libc, -lc)
mbrlen(const char * restrict s, size_t n, mbstate_t * restrict ps);
The mbrlen() function inspects at most n bytes pointed to by s to determine the number of bytes needed to complete the next multibyte charac-
The mbstate_t argument, ps, is used to keep track of the shift state. If it is NULL, mbrlen() uses an internal, static mbstate_t object,
which is initialized to the initial conversion state at program startup.
It is equivalent to:
mbrtowc(NULL, s, n, ps);
Except that when ps is a NULL pointer, mbrlen() uses its own static, internal mbstate_t object to keep track of the shift state.
The mbrlen() functions returns:
0 The next n or fewer bytes represent the null wide character (L'