Commit | Line | Data |
d1edabcf |
1 | package open; |
ac27b0f5 |
2 | use Carp; |
16fe6d59 |
3 | $open::hint_bits = 0x20000; |
4 | |
0c4f7ff0 |
5 | our $VERSION = '1.01'; |
b75c8c73 |
6 | |
58d53262 |
7 | my $locale_encoding; |
8 | |
9 | sub in_locale { $^H & $locale::hint_bits } |
10 | |
11 | sub _get_locale_encoding { |
12 | unless (defined $locale_encoding) { |
ba6ce41c |
13 | eval { |
14 | # I18N::Langinfo isn't available everywhere |
15 | require I18N::Langinfo; |
16 | I18N::Langinfo->import('langinfo', 'CODESET'); |
17 | }; |
58d53262 |
18 | unless ($@) { |
ba6ce41c |
19 | $locale_encoding = langinfo(CODESET()); |
58d53262 |
20 | } |
11fc5dc3 |
21 | my $country_language; |
58d53262 |
22 | if (not $locale_encoding && in_locale()) { |
11fc5dc3 |
23 | if ($ENV{LC_ALL} =~ /^([^.]+)\.([^.]+)$/) { |
24 | ($country_language, $locale_encoding) = ($1, $2); |
25 | } elsif ($ENV{LANG} =~ /^([^.]+)\.([^.]+)$/) { |
26 | ($country_language, $locale_encoding) = ($1, $2); |
58d53262 |
27 | } |
28 | } else { |
29 | # Could do heuristics based on the country and language |
30 | # parts of LC_ALL and LANG (the parts before the dot (if any)), |
31 | # since we have Locale::Country and Locale::Language available. |
32 | # TODO: get a database of Language -> Encoding mappings |
33 | # (the Estonian database would be excellent!) |
34 | # --jhi |
35 | } |
11fc5dc3 |
36 | if (defined $locale_encoding && |
37 | $locale_encoding eq 'euc' && |
38 | defined $country_language) { |
56fb2e42 |
39 | if ($country_language =~ /^ja_JP|japan(?:ese)?$/i) { |
11fc5dc3 |
40 | $locale_encoding = 'eucjp'; |
5a192dee |
41 | } elsif ($country_language =~ /^ko_KR|korean?$/i) { |
11fc5dc3 |
42 | $locale_encoding = 'euckr'; |
56fb2e42 |
43 | } elsif ($country_language =~ /^zh_TW|taiwan(?:ese)?$/i) { |
11fc5dc3 |
44 | $locale_encoding = 'euctw'; |
45 | } |
46 | croak "Locale encoding 'euc' too ambiguous" |
47 | if $locale_encoding eq 'euc'; |
48 | } |
58d53262 |
49 | } |
50 | } |
51 | |
16fe6d59 |
52 | sub import { |
dfebf958 |
53 | my ($class,@args) = @_; |
54 | croak("`use open' needs explicit list of disciplines") unless @args; |
16fe6d59 |
55 | $^H |= $open::hint_bits; |
ba6ce41c |
56 | my ($in,$out) = split(/\0/,(${^OPEN} || "\0"), -1); |
dfebf958 |
57 | while (@args) { |
58 | my $type = shift(@args); |
59 | my $discp = shift(@args); |
ac27b0f5 |
60 | my @val; |
dfebf958 |
61 | foreach my $layer (split(/\s+/,$discp)) { |
62 | $layer =~ s/^://; |
58d53262 |
63 | if ($layer eq 'locale') { |
64 | use Encode; |
65 | _get_locale_encoding() |
66 | unless defined $locale_encoding; |
67 | croak "Cannot figure out an encoding to use" |
68 | unless defined $locale_encoding; |
11fc5dc3 |
69 | if ($locale_encoding =~ /^utf-?8$/i) { |
70 | $layer = "utf8"; |
71 | } else { |
f38d7863 |
72 | $layer = "encoding"; |
11fc5dc3 |
73 | } |
58d53262 |
74 | } |
0c4f7ff0 |
75 | unless(PerlIO::Layer::->find($layer)) { |
dfebf958 |
76 | carp("Unknown discipline layer '$layer'"); |
ac27b0f5 |
77 | } |
f38d7863 |
78 | if (defined $locale_encoding) { |
79 | $layer = "$layer($locale_encoding)"; |
80 | } |
ac27b0f5 |
81 | push(@val,":$layer"); |
82 | if ($layer =~ /^(crlf|raw)$/) { |
83 | $^H{"open_$type"} = $layer; |
16fe6d59 |
84 | } |
ac27b0f5 |
85 | } |
86 | if ($type eq 'IN') { |
87 | $in = join(' ',@val); |
88 | } |
89 | elsif ($type eq 'OUT') { |
90 | $out = join(' ',@val); |
16fe6d59 |
91 | } |
f3b00462 |
92 | elsif ($type eq 'INOUT') { |
93 | $in = $out = join(' ',@val); |
94 | } |
16fe6d59 |
95 | else { |
ac27b0f5 |
96 | croak "Unknown discipline class '$type'"; |
16fe6d59 |
97 | } |
98 | } |
ac27b0f5 |
99 | ${^OPEN} = join('\0',$in,$out); |
16fe6d59 |
100 | } |
101 | |
102 | 1; |
103 | __END__ |
d1edabcf |
104 | |
105 | =head1 NAME |
106 | |
107 | open - perl pragma to set default disciplines for input and output |
108 | |
109 | =head1 SYNOPSIS |
110 | |
16fe6d59 |
111 | use open IN => ":crlf", OUT => ":raw"; |
f3b00462 |
112 | use open INOUT => ":utf8"; |
d1edabcf |
113 | |
114 | =head1 DESCRIPTION |
115 | |
d151aa0e |
116 | Full-fledged support for I/O disciplines is now implemented provided |
117 | Perl is configured to use PerlIO as its IO system (which is now the |
118 | default). |
16fe6d59 |
119 | |
7d3b96bb |
120 | The C<open> pragma serves as one of the interfaces to declare default |
121 | "layers" (aka disciplines) for all I/O. |
122 | |
123 | The C<open> pragma is used to declare one or more default layers for |
d151aa0e |
124 | I/O operations. Any open(), readpipe() (aka qx//) and similar |
125 | operators found within the lexical scope of this pragma will use the |
126 | declared defaults. |
7d3b96bb |
127 | |
d151aa0e |
128 | When open() is given an explicit list of layers they are appended to |
129 | the list declared using this pragma. |
7d3b96bb |
130 | |
131 | Directory handles may also support disciplines in future. |
132 | |
133 | =head1 NONPERLIO FUNCTIONALITY |
134 | |
d151aa0e |
135 | If Perl is not built to use PerlIO as its IO system then only the two |
136 | pseudo-disciplines ":raw" and ":crlf" are available. |
16fe6d59 |
137 | |
138 | The ":raw" discipline corresponds to "binary mode" and the ":crlf" |
139 | discipline corresponds to "text mode" on platforms that distinguish |
140 | between the two modes when opening files (which is many DOS-like |
d151aa0e |
141 | platforms, including Windows). These two disciplines are no-ops on |
142 | platforms where binmode() is a no-op, but perform their functions |
143 | everywhere if PerlIO is enabled. |
7d3b96bb |
144 | |
145 | =head1 IMPLEMENTATION DETAILS |
d1edabcf |
146 | |
f3b00462 |
147 | There is a class method in C<PerlIO::Layer> C<find> which is |
148 | implemented as XS code. It is called by C<import> to validate the |
149 | layers: |
0c4f7ff0 |
150 | |
151 | PerlIO::Layer::->find("perlio") |
152 | |
f3b00462 |
153 | The return value (if defined) is a Perl object, of class |
154 | C<PerlIO::Layer> which is created by the C code in F<perlio.c>. As |
155 | yet there is nothing useful you can do with the object at the perl |
156 | level. |
16fe6d59 |
157 | |
d1edabcf |
158 | =head1 SEE ALSO |
159 | |
7d3b96bb |
160 | L<perlfunc/"binmode">, L<perlfunc/"open">, L<perlunicode>, L<PerlIO> |
d1edabcf |
161 | |
162 | =cut |