locale/tolower.3

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  36 .\"     @(#)tolower.3   8.1 (Berkeley) 6/4/93
  37 .\" $FreeBSD: src/lib/libc/locale/tolower.3,v 1.16 2004/08/21 07:37:08 tjr Exp $
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  39 .Dd August 21, 2004
  40 .Dt TOLOWER 3
  41 .Os
  42 .Sh NAME
  43 .Nm tolower ,
  44 .Nm tolower_l
  45 .Nd upper case to lower case letter conversion
  46 .Sh LIBRARY
  47 .Lb libc
  48 .Sh SYNOPSIS
  49 .In ctype.h
  50 .Ft int
  51 .Fo tolower
  52 .Fa "int c"
  53 .Fc
  54 .In ctype.h
  55 .In xlocale.h
  56 .Ft int
  57 .Fo tolower_l
  58 .Fa "int c"
  59 .Fa "locale_t loc"
  60 .Fc
  61 .Sh DESCRIPTION
  62 The
  63 .Fn tolower
  64 function converts an upper-case letter to the corresponding lower-case
  65 letter.
  66 For single C
  67 .Va char Ns s
  68 locales (see
  69 .Xr multibyte 3 ) ,
  70 the value of the argument is
  71 representable as an
  72 .Li unsigned char
  73 or the value of
  74 .Dv EOF .
  75 .Pp
  76 Although the
  77 .Fn tolower
  78 function uses the current locale, the
  79 .Fn tolower_l
  80 function may be passed a locale directly. See
  81 .Xr xlocale 3
  82 for more information.
  83 .Sh RETURN VALUES
  84 If the argument is an upper-case letter, the
  85 .Fn tolower
  86 function returns the corresponding lower-case letter if there is
  87 one; otherwise, the argument is returned unchanged.
  88 .Sh COMPATIBILITY
  89 The
  90 .Bx 4.4
  91 extension of accepting arguments outside of the range of the
  92 .Vt "unsigned char"
  93 type in locales with large character sets is considered obsolete
  94 and may not be supported in future releases.
  95 The
  96 .Fn towlower
  97 function should be used instead.
  98 .Sh SEE ALSO
  99 .Xr ctype 3 ,
 100 .Xr islower 3 ,
 101 .Xr multibyte 3 ,
 102 .Xr towlower 3 ,
 103 .Xr xlocale 3
 104 .Sh STANDARDS
 105 The
 106 .Fn tolower
 107 function conforms to
 108 .St -isoC .