xref: /freebsd/lib/libc/locale/mblen.3 (revision 74bf4e164ba5851606a27d4feff27717452583e5)
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36.\" From @(#)multibyte.3	8.1 (Berkeley) 6/4/93
37.\" From FreeBSD: src/lib/libc/locale/multibyte.3,v 1.22 2003/11/08 03:23:11 tjr Exp
38.\" $FreeBSD$
39.\"
40.Dd April 11, 2004
41.Dt MBLEN 3
42.Os
43.Sh NAME
44.Nm mblen
45.Nd get number of bytes in a character
46.Sh LIBRARY
47.Lb libc
48.Sh SYNOPSIS
49.In stdlib.h
50.Ft int
51.Fn mblen "const char *mbchar" "size_t nbytes"
52.Sh DESCRIPTION
53The
54.Fn mblen
55function computes the length in bytes
56of a multibyte character
57.Fa mbchar
58according to the current conversion state.
59Up to
60.Fa nbytes
61bytes are examined.
62.Pp
63A call with a null
64.Fa mbchar
65pointer returns nonzero if the current locale requires shift states,
66zero otherwise;
67if shift states are required, the shift state is reset to the initial state.
68.Sh RETURN VALUES
69If
70.Fa mbchar
71is
72.Dv NULL ,
73the
74.Fn mblen
75function returns nonzero if shift states are supported,
76zero otherwise.
77.Pp
78Otherwise, if
79.Fa mbchar
80is not a null pointer,
81.Fn mblen
82either returns 0 if
83.Fa mbchar
84represents the null wide character, or returns
85the number of bytes processed in
86.Fa mbchar ,
87or returns \-1 if no multibyte character
88could be recognized or converted.
89In this case,
90.Fn mblen Ns 's
91internal conversion state is undefined.
92.Sh ERRORS
93The
94.Fn mblen
95function will fail if:
96.Bl -tag -width Er
97.It Bq Er EILSEQ
98An invalid multibyte sequence was detected.
99.It Bq Er EINVAL
100The internal conversion state is not valid.
101.El
102.Sh SEE ALSO
103.Xr mbrlen 3 ,
104.Xr mbtowc 3 ,
105.Xr multibyte 3
106.Sh STANDARDS
107The
108.Fn mblen
109function conforms to
110.St -isoC-99 .
111