iswupper(3)

1iswupper(3)                Library Functions Manual                iswupper(3)
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NAME

6       iswupper - test for uppercase wide character
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LIBRARY

9       Standard C library (libc, -lc)
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SYNOPSIS

12       #include <wctype.h>
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14       int iswupper(wint_t wc);
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DESCRIPTION

17       The  iswupper()  function is the wide-character equivalent of the isup‐
18       per(3) function.  It tests whether wc is a wide character belonging  to
19       the wide-character class "upper".
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21       The  wide-character  class  "upper" is a subclass of the wide-character
22       class "alpha", and therefore also  a  subclass  of  the  wide-character
23       class  "alnum",  of  the  wide-character class "graph" and of the wide-
24       character class "print".
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26       Being a subclass of the wide-character class "print", the  wide-charac‐
27       ter class "upper" is disjoint from the wide-character class "cntrl".
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29       Being  a subclass of the wide-character class "graph", the wide-charac‐
30       ter class "upper" is disjoint from the wide-character class "space" and
31       its subclass "blank".
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33       Being  a subclass of the wide-character class "alnum", the wide-charac‐
34       ter class "upper" is disjoint from the wide-character class "punct".
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36       Being a subclass of the wide-character class "alpha", the  wide-charac‐
37       ter class "upper" is disjoint from the wide-character class "digit".
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39       The  wide-character class "upper" contains at least those characters wc
40       which are equal to towupper(wc) and different from towlower(wc).
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42       The wide-character class "upper" always contains at least  the  letters
43       'A' to 'Z'.
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RETURN VALUE

46       The  iswupper()  function returns nonzero if wc is a wide character be‐
47       longing to the wide-character class  "upper".   Otherwise,  it  returns
48       zero.
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ATTRIBUTES

51       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
52       tributes(7).
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54       ┌─────────────────────────────────────┬───────────────┬────────────────┐
55       │Interface                            │ Attribute     │ Value          │
56       ├─────────────────────────────────────┼───────────────┼────────────────┤
57       │iswupper()                           │ Thread safety │ MT-Safe locale │
58       └─────────────────────────────────────┴───────────────┴────────────────┘
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STANDARDS

61       C11, POSIX.1-2008.
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HISTORY

64       POSIX.1-2001, C99.
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NOTES

67       The behavior of iswupper() depends on  the  LC_CTYPE  category  of  the
68       current locale.
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70       This  function  is  not  very  appropriate  for  dealing  with  Unicode
71       characters, because Unicode knows about three cases: upper, lower,  and
72       title case.
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