locale/isdigit.3

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  32 .\"     @(#)isdigit.3   8.1 (Berkeley) 6/4/93
  33 .\" $FreeBSD: src/lib/libc/locale/isdigit.3,v 1.25 2009/09/04 07:44:58 des Exp $
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  35 .Dd May 4, 2007
  36 .Dt ISDIGIT 3
  37 .Os
  38 .Sh NAME
  39 .Nm isdigit, isnumber
  40 .Nd decimal-digit character test
  41 .Sh LIBRARY
  42 .Lb libc
  43 .Sh SYNOPSIS
  44 .In ctype.h
  45 .Ft int
  46 .Fn isdigit "int c"
  47 .Ft int
  48 .Fn isnumber "int c"
  49 .Sh DESCRIPTION
  50 The
  51 .Fn isdigit
  52 function tests for a decimal digit character.
  53 Regardless of locale, this includes the following characters only:
  54 .Pp
  55 .Bl -column \&``0''______ \&``0''______ \&``0''______ \&``0''______ \&``0''______
  56 .It "\&``0''\t``1''\t``2''\t``3''\t``4''"
  57 .It "\&``5''\t``6''\t``7''\t``8''\t``9''"
  58 .El
  59 .Pp
  60 The
  61 .Fn isnumber
  62 function behaves similarly to
  63 .Fn isdigit ,
  64 but may recognize additional characters, depending on the current locale
  65 setting.
  66 .Pp
  67 The value of the argument must be representable as an
  68 .Vt "unsigned char"
  69 or the value of
  70 .Dv EOF .
  71 .Sh RETURN VALUES
  72 The
  73 .Fn isdigit
  74 and
  75 .Fn isnumber
  76 functions return zero if the character tests false and
  77 return non-zero if the character tests true.
  78 .Sh COMPATIBILITY
  79 The
  80 .Bx 4.4
  81 extension of accepting arguments outside of the range of the
  82 .Vt "unsigned char"
  83 type in locales with large character sets is considered obsolete
  84 and may not be supported in future releases.
  85 The
  86 .Fn iswdigit
  87 function should be used instead.
  88 .Sh SEE ALSO
  89 .Xr ctype 3 ,
  90 .Xr isalnum_l 3 ,
  91 .Xr iswdigit 3 ,
  92 .Xr multibyte 3 ,
  93 .Xr ascii 7
  94 .Sh STANDARDS
  95 The
  96 .Fn isdigit
  97 function conforms to
  98 .St -isoC .
  99 .Sh HISTORY
 100 The
 101 .Fn isnumber
 102 function appeared in
 103 .Bx 4.4 .