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mbrlen (3)

mbrlen (3) ( Solaris man: Библиотечные вызовы )

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mbrlen (3) ( Русские man: Библиотечные вызовы )

mbrlen (3) ( Linux man: Библиотечные вызовы )

mbrlen (3) ( POSIX man: Библиотечные вызовы )

BSD mandoc

NAME



mbrlen

 - get number of bytes in a character (restartable)

LIBRARY

Lb libc

SYNOPSIS

#include <wchar.h>
size_t mbrlen (const char * restrict s size_t n mbstate_t * restrict ps);

DESCRIPTION

The mbrlen ();
function inspects at most Fa n bytes pointed to by Fa s to determine the number of bytes needed to complete the next multibyte character.

The Vt mbstate_t argument, Fa ps , is used to keep track of the shift state. If it is NULL mbrlen ();
uses an internal, static Vt 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 Fa ps is a NULL pointer, mbrlen ();
uses its own static, internal Vt mbstate_t object to keep track of the shift state.

RETURN VALUES

The mbrlen ();
functions returns:

0: The next Fa n or fewer bytes represent the null wide character (L'\0' )
>0: The next Fa n or fewer bytes represent a valid character, mbrlen ();
returns the number of bytes used to complete the multibyte character.
Po Vt size_t Pc -2: The next Fa n contribute to, but do not complete, a valid multibyte character sequence, and all Fa n bytes have been processed.
Po Vt size_t Pc -1: An encoding error has occurred. The next Fa n or fewer bytes do not contribute to a valid multibyte character.

EXAMPLES

A function that calculates the number of characters in a multibyte character string:

size_t
nchars(const char *s)
{
        size_t charlen, chars;
        mbstate_t mbs;

        chars = 0;
        memset(&mbs, 0, sizeof(mbs));
        while ((charlen = mbrlen(s, MB_CUR_MAX, &mbs)) != 0 &&
            charlen != (size_t)-1 && charlen != (size_t)-2) {
                s += charlen;
                chars++;
        }

        return (chars);
}