package open;
+use warnings;
use Carp;
-$open::hint_bits = 0x20000;
+$open::hint_bits = 0x20000; # HINT_LOCALIZE_HH
our $VERSION = '1.01';
} elsif ($ENV{LANG} =~ /^([^.]+)\.([^.]+)$/) {
($country_language, $locale_encoding) = ($1, $2);
}
+ # LANGUAGE affects only LC_MESSAGES only on glibc
} elsif (not $locale_encoding) {
if ($ENV{LC_ALL} =~ /\butf-?8\b/i ||
$ENV{LANG} =~ /\butf-?8\b/i) {
} elsif ($country_language =~ /^zh_CN|chin(?:a|ese)?$/i) {
$locale_encoding = 'euc-cn';
} elsif ($country_language =~ /^zh_TW|taiwan(?:ese)?$/i) {
- $locale_encoding = 'big5';
+ $locale_encoding = 'euc-tw';
}
croak "Locale encoding 'euc' too ambiguous"
if $locale_encoding eq 'euc';
sub import {
my ($class,@args) = @_;
- croak("`use open' needs explicit list of disciplines") unless @args;
+ croak("`use open' needs explicit list of PerlIO layers") unless @args;
my $std;
$^H |= $open::hint_bits;
my ($in,$out) = split(/\0/,(${^OPEN} || "\0"), -1);
foreach my $layer (split(/\s+/,$dscp)) {
$layer =~ s/^://;
if ($layer eq 'locale') {
- use Encode;
+ require Encode;
_get_locale_encoding()
unless defined $locale_encoding;
- (carp("Cannot figure out an encoding to use"), last)
+ (warnings::warnif("layer", "Cannot figure out an encoding to use"), last)
unless defined $locale_encoding;
if ($locale_encoding =~ /^utf-?8$/i) {
$layer = "utf8";
}
$std = 1;
} else {
- unless(PerlIO::Layer::->find($layer)) {
- carp("Unknown discipline layer '$layer'");
+ my $target = $layer; # the layer name itself
+ $target =~ s/^(\w+)\(.+\)$/$1/; # strip parameters
+
+ unless(PerlIO::Layer::->find($target,1)) {
+ warnings::warnif("layer", "Unknown PerlIO layer '$target'");
}
}
push(@val,":$layer");
$in = $out = join(' ',@val);
}
else {
- croak "Unknown discipline class '$type'";
+ croak "Unknown PerlIO layer class '$type'";
}
}
${^OPEN} = join("\0",$in,$out) if $in or $out;
=head1 NAME
-open - perl pragma to set default disciplines for input and output
+open - perl pragma to set default PerlIO layers for input and output
=head1 SYNOPSIS
- use open IN => ":crlf", OUT => ":raw";
+ use open IN => ":crlf", OUT => ":bytes";
use open OUT => ':utf8';
use open IO => ":encoding(iso-8859-7)";
=head1 DESCRIPTION
-Full-fledged support for I/O disciplines is now implemented provided
+Full-fledged support for I/O layers 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.
+"layers" (also known as "disciplines") for all I/O. Any two-argument
+open(), readpipe() (aka qx//) and similar operators found within the
+lexical scope of this pragma will use the declared defaults.
+Three-argument opens are not affected by this pragma since there you
+(can) explicitly specify the layers and are supposed to know what you
+are doing.
With the C<IN> subpragma you can declare the default layers
of input streams, and with the C<OUT> subpragma you can declare
If you have a legacy encoding, you can use the C<:encoding(...)> tag.
-if you want to set your encoding disciplines based on your
+if you want to set your encoding layers based on your
locale environment variables, you can use the C<:locale> tag.
For example:
use open ':encoding(iso-8859-7)';
use open IO => ':encoding(iso-8859-7)';
+The matching of encoding names is loose: case does not matter, and
+many encodings have several aliases. See L<Encode::Supported> for
+details and the list of supported locales.
+
+Note that C<:utf8> PerlIO layer must always be specified exactly like
+that, it is not subject to the loose matching of encoding names.
+
When open() is given an explicit list of layers they are appended to
the list declared using this pragma.
=back
-Directory handles may also support disciplines in future.
+If your locale environment variables (LC_ALL, LC_CTYPE, LANG)
+contain the strings 'UTF-8' or 'UTF8' (case-insensitive matching),
+the default encoding of your STDIN, STDOUT, and STDERR, and of
+B<any subsequent file open>, is UTF-8.
+
+Directory handles may also support PerlIO layers in the 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.
+pseudo-layers C<:bytes> and C<:crlf> are available.
-The ":raw" discipline corresponds to "binary mode" and the ":crlf"
-discipline corresponds to "text mode" on platforms that distinguish
+The C<:bytes> layer corresponds to "binary mode" and the C<:crlf>
+layer 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 no-ops on
+platforms, including Windows). These two layers are no-ops on
platforms where binmode() is a no-op, but perform their functions
everywhere if PerlIO is enabled.