towlower(3)

1TOWLOWER(3)                Linux Programmer's Manual               TOWLOWER(3)
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NAME

6       towlower, towlower_l - convert a wide character to lowercase
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SYNOPSIS

9       #include <wctype.h>
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11       wint_t towlower(wint_t wc);
12       wint_t towlower_l(wint_t wc, locale_t locale);
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14   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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16       towlower_l():
17           Since glibc 2.10:
18               _XOPEN_SOURCE >= 700
19           Before glibc 2.10:
20               _GNU_SOURCE
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DESCRIPTION

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

39       If wc was convertible to lowercase, towlower()  returns  its  lowercase
40       equivalent; otherwise it returns wc.
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VERSIONS

43       The towlower_l() function first appeared in glibc 2.3.
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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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CONFORMING TO

58       towlower(): C99, POSIX.1-2001 (XSI); present as  an  XSI  extension  in
59       POSIX.1-2008, but marked obsolete.
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61       towlower_l(): POSIX.1-2008.
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NOTES

64       The behavior of these functions depends on the LC_CTYPE category of the
65       locale.
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67       These functions are not very appropriate for dealing with Unicode char‐
68       acters,  because Unicode knows about three cases: upper, lower, and ti‐
69       tle case.
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COLOPHON

75       This page is part of release 5.13 of the Linux  man-pages  project.   A
76       description  of  the project, information about reporting bugs, and the
77       latest    version    of    this    page,    can     be     found     at
78       https://www.kernel.org/doc/man-pages/.
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82GNU                               2021-03-22                       TOWLOWER(3)