locale/mblen.3

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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: src/lib/libc/locale/mblen.3,v 1.5 2004/07/05 06:36:36 ru Exp $
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  40 .Dd April 11, 2004
  41 .Dt MBLEN 3
  42 .Os
  43 .Sh NAME
  44 .Nm mblen ,
  45 .Nm mblen_l
  46 .Nd get number of bytes in a character
  47 .Sh LIBRARY
  48 .Lb libc
  49 .Sh SYNOPSIS
  50 .In stdlib.h
  51 .Ft int
  52 .Fo mblen
  53 .Fa "const char *s"
  54 .Fa "size_t n"
  55 .Fc
  56 .In stdlib.h
  57 .In xlocale.h
  58 .Ft int
  59 .Fo mblen_l
  60 .Fa "const char *s"
  61 .Fa "size_t n"
  62 .Fa "locale_t loc"
  63 .Fc
  64 .Sh DESCRIPTION
  65 The
  66 .Fn mblen
  67 function computes the length, in bytes,
  68 of a multibyte character
  69 .Fa s ,
  70 according to the current conversion state.
  71 Up to
  72 .Fa n
  73 bytes are examined.
  74 .Pp
  75 A call with a null
  76 .Fa s
  77 pointer returns nonzero if the current locale requires shift states,
  78 zero otherwise.
  79 If shift states are required, the shift state is reset to the initial state.
  80 .Pp
  81 Although the
  82 .Fn mblen
  83 function uses the current locale, the
  84 .Fn mblen_l
  85 function may be passed a locale directly. See
  86 .Xr xlocale 3
  87 for more information.
  88 .Sh RETURN VALUES
  89 If
  90 .Fa s
  91 is
  92 .Dv NULL ,
  93 the
  94 .Fn mblen
  95 function returns nonzero if shift states are supported,
  96 zero otherwise.
  97 .Pp
  98 Otherwise, if
  99 .Fa s
 100 is not a null pointer,
 101 .Fn mblen
 102 either returns 0 if
 103 .Fa s
 104 represents the null wide character, or returns
 105 the number of bytes processed in
 106 .Fa s ,
 107 or returns \-1 if no multibyte character
 108 could be recognized or converted.
 109 In this case,
 110 .Fn mblen Ns 's
 111 internal conversion state is undefined.
 112 .Sh ERRORS
 113 The
 114 .Fn mblen
 115 function will fail if:
 116 .Bl -tag -width Er
 117 .It Bq Er EILSEQ
 118 An invalid multibyte sequence was detected.
 119 .It Bq Er EINVAL
 120 The internal conversion state is not valid.
 121 .El
 122 .Sh SEE ALSO
 123 .Xr mbrlen 3 ,
 124 .Xr mbtowc 3 ,
 125 .Xr multibyte 3 ,
 126 .Xr xlocale 3
 127 .Sh STANDARDS
 128 The
 129 .Fn mblen
 130 function conforms to
 131 .St -isoC-99 .