xref: /freebsd/lib/libc/locale/mblen.3 (revision 2f02600abfddfc4e9f20dd384a2e729b451e16bd)
1.\" Copyright (c) 2002-2004 Tim J. Robbins. All rights reserved.
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32.\" From @(#)multibyte.3	8.1 (Berkeley) 6/4/93
33.\" From FreeBSD: src/lib/libc/locale/multibyte.3,v 1.22 2003/11/08 03:23:11 tjr Exp
34.\" $FreeBSD$
35.\"
36.Dd April 11, 2004
37.Dt MBLEN 3
38.Os
39.Sh NAME
40.Nm mblen
41.Nd get number of bytes in a character
42.Sh LIBRARY
43.Lb libc
44.Sh SYNOPSIS
45.In stdlib.h
46.Ft int
47.Fn mblen "const char *mbchar" "size_t nbytes"
48.Sh DESCRIPTION
49The
50.Fn mblen
51function computes the length in bytes
52of a multibyte character
53.Fa mbchar
54according to the current conversion state.
55Up to
56.Fa nbytes
57bytes are examined.
58.Pp
59A call with a null
60.Fa mbchar
61pointer returns nonzero if the current locale requires shift states,
62zero otherwise;
63if shift states are required, the shift state is reset to the initial state.
64.Sh RETURN VALUES
65If
66.Fa mbchar
67is
68.Dv NULL ,
69the
70.Fn mblen
71function returns nonzero if shift states are supported,
72zero otherwise.
73.Pp
74Otherwise, if
75.Fa mbchar
76is not a null pointer,
77.Fn mblen
78either returns 0 if
79.Fa mbchar
80represents the null wide character, or returns
81the number of bytes processed in
82.Fa mbchar ,
83or returns \-1 if no multibyte character
84could be recognized or converted.
85In this case,
86.Fn mblen Ns 's
87internal conversion state is undefined.
88.Sh ERRORS
89The
90.Fn mblen
91function will fail if:
92.Bl -tag -width Er
93.It Bq Er EILSEQ
94An invalid multibyte sequence was detected.
95.It Bq Er EINVAL
96The internal conversion state is not valid.
97.El
98.Sh SEE ALSO
99.Xr mbrlen 3 ,
100.Xr mbtowc 3 ,
101.Xr multibyte 3
102.Sh STANDARDS
103The
104.Fn mblen
105function conforms to
106.St -isoC-99 .
107