mbrlen

Defined in header `<wchar.h>`
size_t mbrlen( const char s, size_t n, mbstate_t ps );		(since C95)
size_t mbrlen( const char restrict s, size_t n, mbstate_t restrict ps );		(since C99)

Determines the size, in bytes, of the representation of a multibyte character.

This function is equivalent to the call mbrtowc(nullptr, s, n, ps?ps:&internal) for some hidden object internal of type mbstate_t, except that the expression ps is evaluated only once.

Parameters

s	-	pointer to an element of a multibyte character string
n	-	limit on the number of bytes in s that can be examined
ps	-	pointer to the variable holding the conversion state

Return value

The first of the following that applies:

0 if the next n or fewer bytes complete the null character or if s is a null pointer. Both cases reset the conversion state.
the number of bytes [1...n] that complete a valid multibyte character
(size_t)-2 if the next n bytes are part of a possibly valid multibyte character, which is still incomplete after examining all n bytes
(size_t)-1 if encoding error occurs. The value of errno is EILSEQ; the conversion state is unspecified.

Language
headers
Type support
Dynamic memory management
Error handling
Program utilities
Variadic function support
Date and time utilities
Strings library
Algorithms
Numerics
Input/output support
Localization support
Thread support (C11)
Atomic operations (C11)
Technical Specifications