xref: /openbsd-src/gnu/usr.bin/perl/lib/locale.pm (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1package locale;
2
3our $VERSION = '1.02';
4use Config;
5
6$Carp::Internal{ (__PACKAGE__) } = 1;
7
8=head1 NAME
9
10locale - Perl pragma to use or avoid POSIX locales for built-in operations
11
12=head1 SYNOPSIS
13
14    @x = sort @y;	# Unicode sorting order
15    {
16        use locale;
17        @x = sort @y;   # Locale-defined sorting order
18    }
19    @x = sort @y;	# Unicode sorting order again
20
21=head1 DESCRIPTION
22
23This pragma tells the compiler to enable (or disable) the use of POSIX
24locales for built-in operations (for example, LC_CTYPE for regular
25expressions, LC_COLLATE for string comparison, and LC_NUMERIC for number
26formatting).  Each "use locale" or "no locale"
27affects statements to the end of the enclosing BLOCK.
28
29Starting in Perl 5.16, a hybrid mode for this pragma is available,
30
31    use locale ':not_characters';
32
33which enables only the portions of locales that don't affect the character
34set (that is, all except LC_COLLATE and LC_CTYPE).  This is useful when mixing
35Unicode and locales, including UTF-8 locales.
36
37    use locale ':not_characters';
38    use open ":locale";           # Convert I/O to/from Unicode
39    use POSIX qw(locale_h);       # Import the LC_ALL constant
40    setlocale(LC_ALL, "");        # Required for the next statement
41                                  # to take effect
42    printf "%.2f\n", 12345.67'    # Locale-defined formatting
43    @x = sort @y;                 # Unicode-defined sorting order.
44                                  # (Note that you will get better
45                                  # results using Unicode::Collate.)
46
47See L<perllocale> for more detailed information on how Perl supports
48locales.
49
50=head1 NOTE
51
52If your system does not support locales, then loading this module will
53cause the program to die with a message:
54
55    "Your vendor does not support locales, you cannot use the locale
56    module."
57
58=cut
59
60# A separate bit is used for each of the two forms of the pragma, as they are
61# mostly independent, and interact with each other and the unicode_strings
62# feature.  This allows for fast determination of which one(s) of the three
63# are to be used at any given point, and no code has to be written to deal
64# with coming in and out of scopes--it falls automatically out from the hint
65# handling
66
67$locale::hint_bits = 0x4;
68$locale::not_chars_hint_bits = 0x10;
69
70sub import {
71    shift;  # should be 'locale'; not checked
72
73    if(!$Config{d_setlocale}) {
74        ## No locale support found on this Perl, giving up:
75        die('Your vendor does not support locales, you cannot use the locale module.');
76    }
77
78    my $found_not_chars = 0;
79    while (defined (my $arg = shift)) {
80        if ($arg eq ":not_characters") {
81            $^H |= $locale::not_chars_hint_bits;
82
83            # This form of the pragma overrides the other
84            $^H &= ~$locale::hint_bits;
85            $found_not_chars = 1;
86        }
87        else {
88            require Carp;
89            Carp::croak("Unknown parameter '$arg' to 'use locale'");
90        }
91    }
92
93    # Use the plain form if not doing the :not_characters one.
94    $^H |= $locale::hint_bits unless $found_not_chars;
95}
96
97sub unimport {
98    $^H &= ~($locale::hint_bits|$locale::not_chars_hint_bits);
99}
100
1011;
102