use Carp;
$open::hint_bits = 0x20000;
-use vars qw(%layers @layers);
+our $VERSION = '1.01';
-# Populate hash in non-PerlIO case
-%layers = (crlf => 1, raw => 0) unless (@layers);
+my $locale_encoding;
-our $VERSION = '1.00';
+sub in_locale { $^H & $locale::hint_bits }
+
+sub _get_locale_encoding {
+ unless (defined $locale_encoding) {
+ eval {
+ # I18N::Langinfo isn't available everywhere
+ require I18N::Langinfo;
+ I18N::Langinfo->import('langinfo', 'CODESET');
+ };
+ unless ($@) {
+ $locale_encoding = langinfo(CODESET());
+ }
+ my $country_language;
+ if (not $locale_encoding && in_locale()) {
+ if ($ENV{LC_ALL} =~ /^([^.]+)\.([^.]+)$/) {
+ ($country_language, $locale_encoding) = ($1, $2);
+ } elsif ($ENV{LANG} =~ /^([^.]+)\.([^.]+)$/) {
+ ($country_language, $locale_encoding) = ($1, $2);
+ }
+ } else {
+ # Could do heuristics based on the country and language
+ # parts of LC_ALL and LANG (the parts before the dot (if any)),
+ # since we have Locale::Country and Locale::Language available.
+ # TODO: get a database of Language -> Encoding mappings
+ # (the Estonian database at http://www.eki.ee/letter/
+ # would be excellent!) --jhi
+ }
+ if (defined $locale_encoding &&
+ $locale_encoding eq 'euc' &&
+ defined $country_language) {
+ if ($country_language =~ /^ja_JP|japan(?:ese)?$/i) {
+ $locale_encoding = 'eucjp';
+ } elsif ($country_language =~ /^ko_KR|korean?$/i) {
+ $locale_encoding = 'euckr';
+ } elsif ($country_language =~ /^zh_TW|taiwan(?:ese)?$/i) {
+ $locale_encoding = 'euctw';
+ }
+ croak "Locale encoding 'euc' too ambiguous"
+ if $locale_encoding eq 'euc';
+ }
+ }
+}
sub import {
- shift;
- die "`use open' needs explicit list of disciplines" unless @_;
+ my ($class,@args) = @_;
+ croak("`use open' needs explicit list of disciplines") unless @args;
$^H |= $open::hint_bits;
- my ($in,$out) = split(/\0/,(${^OPEN} || '\0'));
- my @in = split(/\s+/,$in);
- my @out = split(/\s+/,$out);
- while (@_) {
- my $type = shift;
- my $discp = shift;
+ my ($in,$out) = split(/\0/,(${^OPEN} || "\0"), -1);
+ while (@args) {
+ my $type = shift(@args);
+ my $discp = shift(@args);
my @val;
- foreach my $layer (split(/\s+:?/,$discp)) {
- unless(exists $layers{$layer}) {
- croak "Unknown discipline layer '$layer'";
+ foreach my $layer (split(/\s+/,$discp)) {
+ $layer =~ s/^://;
+ if ($layer eq 'locale') {
+ use Encode;
+ _get_locale_encoding()
+ unless defined $locale_encoding;
+ croak "Cannot figure out an encoding to use"
+ unless defined $locale_encoding;
+ if ($locale_encoding =~ /^utf-?8$/i) {
+ $layer = "utf8";
+ } else {
+ $layer = "encoding($locale_encoding)";
+ }
+ } else {
+ unless(PerlIO::Layer::->find($layer)) {
+ carp("Unknown discipline layer '$layer'");
+ }
}
push(@val,":$layer");
if ($layer =~ /^(crlf|raw)$/) {
$^H{"open_$type"} = $layer;
}
}
+ # print "# type = $type, val = @val\n";
if ($type eq 'IN') {
$in = join(' ',@val);
}
elsif ($type eq 'OUT') {
$out = join(' ',@val);
}
+ elsif ($type eq 'INOUT') {
+ $in = $out = join(' ',@val);
+ }
else {
croak "Unknown discipline class '$type'";
}
=head1 SYNOPSIS
use open IN => ":crlf", OUT => ":raw";
+ use open INOUT => ":utf8";
=head1 DESCRIPTION
-The open pragma is used to declare one or more default disciplines for
-I/O operations. Any open() and readpipe() (aka qx//) operators found
-within the lexical scope of this pragma will use the declared defaults.
-Neither open() with an explicit set of disciplines, nor sysopen() are
-influenced by this pragma.
+Full-fledged support for I/O disciplines is now implemented provided
+Perl is configured to use PerlIO as its IO system (which is now the
+default).
+
+The C<open> pragma serves as one of the interfaces to declare default
+"layers" (aka disciplines) for all I/O.
+
+The C<open> pragma is used to declare one or more default layers for
+I/O operations. Any open(), readpipe() (aka qx//) and similar
+operators found within the lexical scope of this pragma will use the
+declared defaults.
+
+When open() is given an explicit list of layers they are appended to
+the list declared using this pragma.
-Only the two pseudo-disciplines ":raw" and ":crlf" are currently
-available.
+Directory handles may also support disciplines in future.
+
+=head1 NONPERLIO FUNCTIONALITY
+
+If Perl is not built to use PerlIO as its IO system then only the two
+pseudo-disciplines ":raw" and ":crlf" are available.
The ":raw" discipline corresponds to "binary mode" and the ":crlf"
discipline corresponds to "text mode" on platforms that distinguish
between the two modes when opening files (which is many DOS-like
-platforms, including Windows). These two disciplines are currently
-no-ops on platforms where binmode() is a no-op, but will be
-supported everywhere in future.
-
-=head1 UNIMPLEMENTED FUNCTIONALITY
-
-Full-fledged support for I/O disciplines is currently unimplemented.
-When they are eventually supported, this pragma will serve as one of
-the interfaces to declare default disciplines for all I/O.
+platforms, including Windows). These two disciplines are no-ops on
+platforms where binmode() is a no-op, but perform their functions
+everywhere if PerlIO is enabled.
-In future, any default disciplines declared by this pragma will be
-available by the special discipline name ":DEFAULT", and could be used
-within handle constructors that allow disciplines to be specified.
-This would make it possible to stack new disciplines over the default
-ones.
+=head1 IMPLEMENTATION DETAILS
- open FH, "<:para :DEFAULT", $file or die "can't open $file: $!";
+There is a class method in C<PerlIO::Layer> C<find> which is
+implemented as XS code. It is called by C<import> to validate the
+layers:
-Socket and directory handles will also support disciplines in
-future.
+ PerlIO::Layer::->find("perlio")
-Full support for I/O disciplines will enable all of the supported
-disciplines to work on all platforms.
+The return value (if defined) is a Perl object, of class
+C<PerlIO::Layer> which is created by the C code in F<perlio.c>. As
+yet there is nothing useful you can do with the object at the perl
+level.
=head1 SEE ALSO
-L<perlfunc/"binmode">, L<perlfunc/"open">, L<perlunicode>
+L<perlfunc/"binmode">, L<perlfunc/"open">, L<perlunicode>, L<PerlIO>,
+L<encoding>
=cut
https://perl5.git.perl.org / perl5.git / blobdiff