mbrlen(3)

NAME
mbrlen - determine number of bytes in next multibyte character

LIBRARY
Standard C library (libc, -lc)

SYNOPSIS
#include <wchar.h>

size_t mbrlen(const char s[restrict .n], size_t n,
              mbstate_t *restrict ps);

DESCRIPTION
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() 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.

If ps is NULL, a static anonymous state known only 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 n should be increased.

ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value
 | Thread safety | MT-Unsafe race:mbrlen/!ps

STANDARDS
C11, POSIX.1-2008.

HISTORY
POSIX.1-2001, C99.

NOTES
The behavior of mbrlen() depends on the LC_CTYPE category of the current locale.

SEE ALSO
mbrtowc(3)