Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

FreeBSD 11.0 - man page for mbrlen (freebsd section 3)

MBRLEN(3)						   BSD Library Functions Manual 						 MBRLEN(3)

mbrlen -- get number of bytes in a character (restartable)
Standard C Library (libc, -lc)
#include <wchar.h> size_t 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- ter. 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'\0'). >0 The next n or fewer bytes represent a valid character, mbrlen() returns the number of bytes used to complete the multibyte character. (size_t)-2 The next n contribute to, but do not complete, a valid multibyte character sequence, and all n bytes have been processed. (size_t)-1 An encoding error has occurred. The next n or fewer bytes do not contribute to a valid multibyte character.
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); }
The mbrlen() function will fail if: [EILSEQ] An invalid multibyte sequence was detected. [EINVAL] The conversion state is invalid.
mblen(3), mbrtowc(3), multibyte(3)
The mbrlen() function conforms to ISO/IEC 9899:1999 (``ISO C99'').
April 7, 2004 BSD