locale/FreeBSD/isdigit.3

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  36 .\"     @(#)isdigit.3   8.1 (Berkeley) 6/4/93
  37 .\" $FreeBSD: src/lib/libc/locale/isdigit.3,v 1.16 2002/10/06 10:15:38 tjr Exp $
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  39 .Dd October 6, 2002
  40 .Dt ISDIGIT 3
  41 .Os
  42 .Sh NAME
  43 .Nm isdigit, isnumber
  44 .Nd decimal-digit character test
  45 .Sh LIBRARY
  46 .Lb libc
  47 .Sh SYNOPSIS
  48 .In ctype.h
  49 .Ft int
  50 .Fn isdigit "int c"
  51 .Ft int
  52 .Fn isnumber "int c"
  53 .Sh DESCRIPTION
  54 The
  55 .Fn isdigit
  56 function tests for any decimal-digit character.
  57 For any locale,
  58 this includes the following characters only:
  59 .Pp
  60 .Bl -column \&``0''______ \&``0''______ \&``0''______ \&``0''______ \&``0''______
  61 .It "\&``0''\t``1''\t``2''\t``3''\t``4''"
  62 .It "\&``5''\t``6''\t``7''\t``8''\t``9''"
  63 .El
  64 .Pp
  65 For single C
  66 .Va char Ns s
  67 locales (see
  68 .Xr multibyte 3 )
  69 the value of the argument is
  70 representable as an
  71 .Li unsigned char
  72 or the value of
  73 .Dv EOF .
  74 .Sh RETURN VALUES
  75 The
  76 .Fn isdigit
  77 function returns zero if the character tests false and
  78 returns non-zero if the character tests true.
  79 .Sh COMPATIBILITY
  80 Although
  81 .Fn isdigit
  82 accepts arguments outside of the range of the
  83 .Vt "unsigned char"
  84 type in locales with large character sets,
  85 this is a
  86 .Bx 4.4
  87 extension and the
  88 .Fn iswdigit
  89 function should be used instead for maximum portability.
  90 .Sh SEE ALSO
  91 .Xr ctype 3 ,
  92 .Xr iswdigit 3 ,
  93 .Xr multibyte 3 ,
  94 .Xr ascii 7
  95 .Sh STANDARDS
  96 The
  97 .Fn isdigit
  98 function conforms to
  99 .St -isoC .