man3/iswupper.3

   1 .\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
   2 .\"
   3 .\" SPDX-License-Identifier: GPL-2.0-or-later
   4 .\"
   5 .\" References consulted:
   6 .\"   GNU glibc-2 source code and manual
   7 .\"   Dinkumware C library reference http://www.dinkumware.com/
   8 .\"   OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html
   9 .\"   ISO/IEC 9899:1999
  10 .\"
  11 .TH iswupper 3 (date) "Linux man-pages (unreleased)"
  12 .SH NAME
  13 iswupper \- test for uppercase wide character
  14 .SH LIBRARY
  15 Standard C library
  16 .RI ( libc ", " \-lc )
  17 .SH SYNOPSIS
  18 .nf
  19 .B #include <wctype.h>
  20 .PP
  21 .BI "int iswupper(wint_t " wc );
  22 .fi
  23 .SH DESCRIPTION
  24 The
  25 .BR iswupper ()
  26 function is the wide-character equivalent of the
  27 .BR isupper (3)
  28 function.
  29 It tests whether
  30 .I wc
  31 is a wide character
  32 belonging to the wide-character class "upper".
  33 .PP
  34 The wide-character class "upper" is a subclass of the wide-character class
  35 "alpha", and therefore also a subclass of the wide-character class "alnum", of
  36 the wide-character class "graph" and of the wide-character class "print".
  37 .PP
  38 Being a subclass of the wide-character class "print", the wide-character class
  39 "upper" is disjoint from the wide-character class "cntrl".
  40 .PP
  41 Being a subclass of the wide-character class "graph", the wide-character class
  42 "upper" is disjoint from the wide-character class "space" and its subclass
  43 "blank".
  44 .PP
  45 Being a subclass of the wide-character class "alnum", the wide-character class
  46 "upper" is disjoint from the wide-character class "punct".
  47 .PP
  48 Being a subclass of the wide-character class "alpha", the wide-character class
  49 "upper" is disjoint from the wide-character class "digit".
  50 .PP
  51 The wide-character class "upper" contains at least those characters
  52 .I wc
  53 which are equal to
  54 .I towupper(wc)
  55 and different from
  56 .IR towlower(wc) .
  57 .PP
  58 The wide-character class "upper" always contains at least the
  59 letters \(aqA\(aq to \(aqZ\(aq.
  60 .SH RETURN VALUE
  61 The
  62 .BR iswupper ()
  63 function returns nonzero if
  64 .I wc
  65 is a wide character
  66 belonging to the wide-character class "upper".
  67 Otherwise, it returns zero.
  68 .SH ATTRIBUTES
  69 For an explanation of the terms used in this section, see
  70 .BR attributes (7).
  71 .ad l
  72 .nh
  73 .TS
  74 allbox;
  75 lbx lb lb
  76 l l l.
  77 Interface       Attribute       Value
  78 T{
  79 .BR iswupper ()
  80 T}      Thread safety   MT-Safe locale
  81 .TE
  82 .hy
  83 .ad
  84 .sp 1
  85 .SH STANDARDS
  86 POSIX.1-2001, POSIX.1-2008, C99.
  87 .SH NOTES
  88 The behavior of
  89 .BR iswupper ()
  90 depends on the
  91 .B LC_CTYPE
  92 category of the
  93 current locale.
  94 .PP
  95 This function is not very appropriate for dealing with Unicode characters,
  96 because Unicode knows about three cases: upper, lower, and title case.
  97 .SH SEE ALSO
  98 .BR isupper (3),
  99 .BR iswctype (3),
 100 .BR towupper (3)