MBRLEN(3) GNU MBRLEN(3)
Linux Programmer's Manual Linux Programmer's Manual
May 12, 2000
NAME
mbrlen - determine number of bytes in next multibyte character
SYNOPSIS
#include <wchar.h>
size_t mbrlen (const char* s, size_t n, mbstate_t* ps
DESCRIPTION
The main case for this function is when s is not NULL. In this case,
the mbrlen function inspects at most n bytes of the multibyte string
starting at s and extracts the next complete multibyte character. It
updates the shift state *ps. If the multibyte character is not the
null wide character, it returns the number of bytes that were consumed
from s. If the multibyte character is the null wide character, it
resets the shift state *ps to the initial state and returns 0.
If the n bytes starting at s do not contain a complete multibyte
character, mbrlen keeps track of the partial multibyte character by
updating *ps and returns (size_t)(-2). This can happen even if n >=
MB_CUR_MAX, if the multibyte string contains redundant shift
sequences.
If the multibyte string starting at s contains an invalid multibyte
sequence before the next complete character, mbrlen returns
(size_t)(-1) and sets errno to EILSEQ. In this case, the effects on
*ps are undefined.
A second case is when s is NULL. In this case, n is ignored. If *ps
contains no partially accumulated multibyte character, the mbrlen
function puts *ps in the initial state and returns 0; otherwise it
returns (size_t)(-1) and sets errno to EILSEQ.
In both of the above cases, if ps is a NULL pointer, a static
anonymous state only known to the mbrlen function is used instead.
RETURN VALUE
The mbrlen function returns the number of bytes parsed from the
multibyte sequence starting at s, if a non-null wide character was
recognized. It returns 0, if a null wide character was recognized. It
returns (size_t)(-1) and sets errno to EILSEQ, if an invalid multibyte
sequence was encountered. It returns (size_t)(-2) if it couldn't parse
a complete multibyte character, meaning that the remaining bytes
should be fed to mbrlen in a new call.
CONFORMING TO
ISO/ANSI C, UNIX98
SEE ALSO
- 1 - Formatted: October 25, 2025
MBRLEN(3) GNU MBRLEN(3)
Linux Programmer's Manual Linux Programmer's Manual
May 12, 2000
mbrtowc(3)
NOTES
The behaviour of mbrlen depends on the LC_CTYPE category of the
current locale.
- 2 - Formatted: October 25, 2025
