1I18N::Langinfo(3pm)    Perl Programmers Reference Guide    I18N::Langinfo(3pm)
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NAME

6       I18N::Langinfo - query locale information
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SYNOPSIS

9         use I18N::Langinfo;
10

DESCRIPTION

12       The langinfo() function queries various locale information that can be
13       used to localize output and user interfaces.  It uses the current
14       underlying locale, regardless of whether or not it was called from
15       within the scope of "use locale".  The langinfo() function requires one
16       numeric argument that identifies the locale constant to query: if no
17       argument is supplied, $_ is used.  The numeric constants appropriate to
18       be used as arguments are exportable from I18N::Langinfo.
19
20       The following example will import the langinfo() function itself and
21       three constants to be used as arguments to langinfo(): a constant for
22       the abbreviated first day of the week (the numbering starts from Sunday
23       = 1) and two more constants for the affirmative and negative answers
24       for a yes/no question in the current locale.
25
26           use I18N::Langinfo qw(langinfo ABDAY_1 YESSTR NOSTR);
27
28           my ($abday_1, $yesstr, $nostr) =
29               map { langinfo($_) } (ABDAY_1, YESSTR, NOSTR);
30
31           print "$abday_1? [$yesstr/$nostr] ";
32
33       In other words, in the "C" (or English) locale the above will probably
34       print something like:
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36           Sun? [yes/no]
37
38       but under a French locale
39
40           dim? [oui/non]
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42       The usually available constants are as follows.
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44       •   For abbreviated and full length days of the week and months of the
45           year:
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47               ABDAY_1 ABDAY_2 ABDAY_3 ABDAY_4 ABDAY_5 ABDAY_6 ABDAY_7
48               ABMON_1 ABMON_2 ABMON_3 ABMON_4 ABMON_5 ABMON_6
49               ABMON_7 ABMON_8 ABMON_9 ABMON_10 ABMON_11 ABMON_12
50               DAY_1 DAY_2 DAY_3 DAY_4 DAY_5 DAY_6 DAY_7
51               MON_1 MON_2 MON_3 MON_4 MON_5 MON_6
52               MON_7 MON_8 MON_9 MON_10 MON_11 MON_12
53
54       •   For the date-time, date, and time formats used by the strftime()
55           function (see POSIX):
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57               D_T_FMT D_FMT T_FMT
58
59       •   For the locales for which it makes sense to have ante meridiem and
60           post meridiem time formats:
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62               AM_STR PM_STR T_FMT_AMPM
63
64       •   For the character code set being used (such as "ISO8859-1",
65           "cp850", "koi8-r", "sjis", "utf8", etc.), and for the currency
66           string:
67
68               CODESET CRNCYSTR
69
70       •   For an alternate representation of digits, for the radix character
71           used between the integer and the fractional part of decimal
72           numbers, the group separator string for large-ish floating point
73           numbers (yes, the final two are redundant with
74           POSIX::localeconv()):
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76               ALT_DIGITS RADIXCHAR THOUSEP
77
78       •   For the affirmative and negative responses and expressions:
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80               YESSTR YESEXPR NOSTR NOEXPR
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82       •   For the eras based on typically some ruler, such as the Japanese
83           Emperor (naturally only defined in the appropriate locales):
84
85               ERA ERA_D_FMT ERA_D_T_FMT ERA_T_FMT
86
87   For systems without "nl_langinfo"
88       Starting in Perl 5.28, this module is available even on systems that
89       lack a native "nl_langinfo".  On such systems, it uses various methods
90       to construct what that function, if present, would return.  But there
91       are potential glitches.  These are the items that could be different:
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93       "ERA"
94           Unimplemented, so returns "".
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96       "CODESET"
97           Unimplemented, except on Windows, due to the vagaries of vendor
98           locale names, returning "" on non-Windows.
99
100       "YESEXPR"
101       "YESSTR"
102       "NOEXPR"
103       "NOSTR"
104           Only the values for English are returned.  "YESSTR" and "NOSTR"
105           have been removed from POSIX 2008, and are retained here for
106           backwards compatibility.  Your platform's "nl_langinfo" may not
107           support them.
108
109       "D_FMT"
110           Always evaluates to %x, the locale's appropriate date
111           representation.
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113       "T_FMT"
114           Always evaluates to %X, the locale's appropriate time
115           representation.
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117       "D_T_FMT"
118           Always evaluates to %c, the locale's appropriate date and time
119           representation.
120
121       "CRNCYSTR"
122           The return may be incorrect for those rare locales where the
123           currency symbol replaces the radix character.  Send email to
124           <mailto:perlbug@perl.org> if you have examples of it needing to
125           work differently.
126
127       "ALT_DIGITS"
128           Currently this gives the same results as Linux does.  Send email to
129           <mailto:perlbug@perl.org> if you have examples of it needing to
130           work differently.
131
132       "ERA_D_FMT"
133       "ERA_T_FMT"
134       "ERA_D_T_FMT"
135       "T_FMT_AMPM"
136           These are derived by using "strftime()", and not all versions of
137           that function know about them.  "" is returned for these on such
138           systems.
139
140       See your nl_langinfo(3) for more information about the available
141       constants.  (Often this means having to look directly at the langinfo.h
142       C header file.)
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144   EXPORT
145       By default only the "langinfo()" function is exported.
146

BUGS

148       Before Perl 5.28, the returned values are unreliable for the
149       "RADIXCHAR" and "THOUSEP" locale constants.
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151       Starting in 5.28, changing locales on threaded builds is supported on
152       systems that offer thread-safe locale functions.  These include POSIX
153       2008 systems and Windows starting with Visual Studio 2005, and this
154       module will work properly in such situations.  However, on threaded
155       builds on Windows prior to Visual Studio 2015, retrieving the items
156       "CRNCYSTR" and "THOUSEP" can result in a race with a thread that has
157       converted to use the global locale.  It is quite uncommon for a thread
158       to have done this.  It would be possible to construct a workaround for
159       this; patches welcome: see "switch_to_global_locale" in perlapi.
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SEE ALSO

162       perllocale, "localeconv" in POSIX, "setlocale" in POSIX,
163       nl_langinfo(3).
164
165       The langinfo() function is just a wrapper for the C nl_langinfo()
166       interface.
167

AUTHOR

169       Jarkko Hietaniemi, <jhi@hut.fi>.  Now maintained by Perl 5 porters.
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172       Copyright 2001 by Jarkko Hietaniemi
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174       This library is free software; you can redistribute it and/or modify it
175       under the same terms as Perl itself.
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179perl v5.34.1                      2022-03-15               I18N::Langinfo(3pm)
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