locale/FreeBSD/mblen.3

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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: src/lib/libc/locale/mblen.3,v 1.6 2007/01/09 00:28:00 imp Exp $
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  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
  49 The
  50 .Fn mblen
  51 function computes the length in bytes
  52 of a multibyte character
  53 .Fa mbchar
  54 according to the current conversion state.
  55 Up to
  56 .Fa nbytes
  57 bytes are examined.
  58 .Pp
  59 A call with a null
  60 .Fa mbchar
  61 pointer returns nonzero if the current locale requires shift states,
  62 zero otherwise;
  63 if shift states are required, the shift state is reset to the initial state.
  64 .Sh RETURN VALUES
  65 If
  66 .Fa mbchar
  67 is
  68 .Dv NULL ,
  69 the
  70 .Fn mblen
  71 function returns nonzero if shift states are supported,
  72 zero otherwise.
  73 .Pp
  74 Otherwise, if
  75 .Fa mbchar
  76 is not a null pointer,
  77 .Fn mblen
  78 either returns 0 if
  79 .Fa mbchar
  80 represents the null wide character, or returns
  81 the number of bytes processed in
  82 .Fa mbchar ,
  83 or returns \-1 if no multibyte character
  84 could be recognized or converted.
  85 In this case,
  86 .Fn mblen Ns 's
  87 internal conversion state is undefined.
  88 .Sh ERRORS
  89 The
  90 .Fn mblen
  91 function will fail if:
  92 .Bl -tag -width Er
  93 .It Bq Er EILSEQ
  94 An invalid multibyte sequence was detected.
  95 .It Bq Er EINVAL
  96 The 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
 103 The
 104 .Fn mblen
 105 function conforms to
 106 .St -isoC-99 .