towlower(3)

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

6       towlower, towlower_l - convert a wide character to lowercase
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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       wint_t towlower(wint_t wc);
15       wint_t towlower_l(wint_t wc, locale_t locale);
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17   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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19       towlower_l():
20           Since glibc 2.10:
21               _XOPEN_SOURCE >= 700
22           Before glibc 2.10:
23               _GNU_SOURCE
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DESCRIPTION

26       The  towlower()  function  is  the  wide-character  equivalent  of  the
27       tolower(3) function.  If wc is an uppercase wide character,  and  there
28       exists  a  lowercase  equivalent  in the current locale, it returns the
29       lowercase equivalent of wc.  In all other cases,  wc  is  returned  un‐
30       changed.
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32       The towlower_l() function performs the same task, but performs the con‐
33       version based on the character type information in the locale specified
34       by  locale.  The behavior of towlower_l() is undefined if locale is the
35       special locale object LC_GLOBAL_LOCALE (see duplocale(3)) or is  not  a
36       valid locale object handle.
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38       The argument wc must be representable as a wchar_t and be a valid char‐
39       acter in the locale or be the value WEOF.
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RETURN VALUE

42       If wc was convertible to lowercase, towlower()  returns  its  lowercase
43       equivalent; otherwise it returns wc.
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ATTRIBUTES

46       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
47       tributes(7).
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49       ┌─────────────────────────────────────┬───────────────┬────────────────┐
50       │Interface                            │ Attribute     │ Value          │
51       ├─────────────────────────────────────┼───────────────┼────────────────┤
52       │towlower()                           │ Thread safety │ MT-Safe locale │
53       ├─────────────────────────────────────┼───────────────┼────────────────┤
54       │towlower_l()                         │ Thread safety │ MT-Safe        │
55       └─────────────────────────────────────┴───────────────┴────────────────┘
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STANDARDS

58       towlower()
59              C11, POSIX.1-2008 (XSI).
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61       towlower_l()
62              POSIX.1-2008.
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STANDARDS

65       towlower()
66              C99, POSIX.1-2001 (XSI).  Obsolete in POSIX.1-2008 (XSI).
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68       towlower_l()
69              glibc 2.3.  POSIX.1-2008.
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NOTES

72       The behavior of these functions depends on the LC_CTYPE category of the
73       locale.
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75       These functions are not very appropriate for dealing with Unicode char‐
76       acters, because Unicode knows about three cases: upper, lower, and  ti‐
77       tle case.
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