package I18N::Langinfo;

use 5.006;
use strict;
use warnings;
use Carp;

require Exporter;
require DynaLoader;
use AutoLoader;

our @ISA = qw(Exporter DynaLoader);

our @EXPORT = qw(langinfo);

our @EXPORT_OK = qw(
	ABDAY_1
	ABDAY_2
	ABDAY_3
	ABDAY_4
	ABDAY_5
	ABDAY_6
	ABDAY_7
	ABMON_1
	ABMON_10
	ABMON_11
	ABMON_12
	ABMON_2
	ABMON_3
	ABMON_4
	ABMON_5
	ABMON_6
	ABMON_7
	ABMON_8
	ABMON_9
	ALT_DIGITS
	AM_STR
	CODESET
	CRNCYSTR
	DAY_1
	DAY_2
	DAY_3
	DAY_4
	DAY_5
	DAY_6
	DAY_7
	D_FMT
	D_T_FMT
	ERA
	ERA_D_FMT
	ERA_D_T_FMT
	ERA_T_FMT
	MON_1
	MON_10
	MON_11
	MON_12
	MON_2
	MON_3
	MON_4
	MON_5
	MON_6
	MON_7
	MON_8
	MON_9
	NOEXPR
	NOSTR
	PM_STR
	RADIXCHAR
	THOUSEP
	T_FMT
	T_FMT_AMPM
	YESEXPR
	YESSTR
);

our $VERSION = '0.01';

sub AUTOLOAD {
    # This AUTOLOAD is used to 'autoload' constants from the constant()
    # XS function.

    my $constname;
    our $AUTOLOAD;
    ($constname = $AUTOLOAD) =~ s/.*:://;
    croak "&I18N::Langinfo::constant not defined" if $constname eq 'constant';
    my ($error, $val) = constant($constname);
    if ($error) { croak $error; }
    {
	no strict 'refs';
	# Fixed between 5.005_53 and 5.005_61
#XXX	if ($] >= 5.00561) {
#XXX	    *$AUTOLOAD = sub () { $val };
#XXX	}
#XXX	else {
	    *$AUTOLOAD = sub { $val };
#XXX	}
    }
    goto &$AUTOLOAD;
}

bootstrap I18N::Langinfo $VERSION;

1;
__END__

=head1 NAME

I18N::Langinfo - query locale information

=head1 SYNOPSIS

  use I18N::Langinfo;

=head1 DESCRIPTION

The langinfo() function queries various locale information that can be
used to localize output and user interfaces.  The langinfo() requires
one numeric argument that identifies the locale constant to query:
if no argument is supplied, C<$_> is used.  The numeric constants
appropriate to be used as arguments are exportable from I18N::Langinfo.

The following example will import the langinfo() function itself and
three constants to be used as arguments to langinfo(): a constant for
the abbreviated first day of the week (the numbering starts from
Sunday = 1) and two more constants for the affirmative and negative
answers for a yes/no question in the current locale.

    use I18N::Langinfo qw(langinfo ABDAY_1 YESSTR NOSTR);

    my ($abday_1, $yesstr, $nostr) = map { langinfo } qw(ABDAY_1 YESSTR NOSTR);

    print "$abday_1? [$yesstr/$nostr] ";

In other words, in the "C" (or English) locale the above will probably
print something like:

    Sun? [yes/no] 

but under a French locale

    dim? [oui/non] 

The usually available constants are

    ABDAY_1 ABDAY_2 ABDAY_3 ABDAY_4 ABDAY_5 ABDAY_6 ABDAY_7
    ABMON_1 ABMON_2 ABMON_3 ABMON_4 ABMON_5 ABMON_6
    ABMON_7 ABMON_8 ABMON_9 ABMON_10 ABMON_11 ABMON_12
    DAY_1 DAY_2 DAY_3 DAY_4 DAY_5 DAY_6 DAY_7
    MON_1 MON_2 MON_3 MON_4 MON_5 MON_6
    MON_7 MON_8 MON_9 MON_10 MON_11 MON_12

for abbreviated and full length days of the week and months of the year,

    D_T_FMT D_FMT T_FMT

for the date-time, date, and time formats used by the strftime() function
(see L<POSIX>)

    AM_STR PM_STR T_FMT_AMPM

for the locales for which it makes sense to have ante meridiem and post
meridiem time formats,

    CODESET CRNCYSTR RADIXCHAR

for the character code set being used (such as "ISO8859-1", "cp850",
"koi8-r", "sjis", "utf8", etc.), for the currency string, for the
radix character used between the integer and the fractional part
of decimal numbers (yes, this is redundant with POSIX::localeconv())

    YESSTR YESEXPR NOSTR NOEXPR

for the affirmative and negative responses and expressions, and

    ERA ERA_D_FMT ERA_D_T_FMT ERA_T_FMT

for the Japanese Emperor eras (naturally only defined under Japanese locales).

See your L<langinfo(3)> for more information about the available
constants.  (Often this means having to look directly at the
F<langinfo.h> C header file.)

Note that unfortunately none of the above constants are guaranteed
to be available on a particular platform.  To be on the safe side
you can wrap the import in an eval like this:

    eval {
        require I18N::Langinfo;
        I18N::Langinfo->import(qw(langinfo CODESET));
        $codeset = langinfo(CODESET()); # note the ()
    };
    if (!$@) { ... failed ... }

=head2 EXPORT

Nothing is exported by default.

=head1 SEE ALSO

L<perllocale>, L<POSIX/localeconv>, L<POSIX/setlocale>, L<nl_langinfo(3)>.

The langinfo() is just a wrapper for the C nl_langinfo() interface.

=head1 AUTHOR

Jarkko Hietaniemi, E<lt>[email protected]<gt>

=head1 COPYRIGHT AND LICENSE

Copyright 2001 by Jarkko Hietaniemi

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself. 

=cut