1 .\" Copyright (c) 2002-2004 Tim J. Robbins
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25 .\" $FreeBSD: src/lib/libc/locale/mbrlen.3,v 1.8 2004/06/30 19:32:41 ru Exp $
32 .Nd "get number of bytes in a character (restartable)"
38 .Fn mbrlen "const char * restrict s" "size_t n" "mbstate_t * restrict ps"
42 function inspects at most
46 to determine the number of bytes needed to complete the next
53 is used to keep track of the shift state.
57 uses an internal, static
59 object, which is initialized to the initial conversion state
64 .Dl "mbrtowc(NULL, s, n, ps);"
72 uses its own static, internal
74 object to keep track of the shift state.
79 .Bl -tag -width indent
84 represent the null wide character
90 represent a valid character,
92 returns the number of bytes used to complete the multibyte character.
93 .It Po Vt size_t Pc Ns \-2
96 contribute to, but do not complete, a valid multibyte character sequence,
99 bytes have been processed.
100 .It Po Vt size_t Pc Ns \-1
101 An encoding error has occurred.
104 or fewer bytes do not contribute to a valid multibyte character.
107 A function that calculates the number of characters in a multibyte
109 .Bd -literal -offset indent
111 nchars(const char *s)
113 size_t charlen, chars;
117 memset(&mbs, 0, sizeof(mbs));
118 while ((charlen = mbrlen(s, MB_CUR_MAX, &mbs)) != 0 &&
119 charlen != (size_t)-1 && charlen != (size_t)-2) {
130 function will fail if:
133 An invalid multibyte sequence was detected.
135 The conversion state is invalid.