package Encode;
-
-$VERSION = 0.01;
+use strict;
+our $VERSION = do { my @r = (q$Revision: 1.26 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
+our $DEBUG = 0;
require DynaLoader;
require Exporter;
-@ISA = qw(Exporter DynaLoader);
+our @ISA = qw(Exporter DynaLoader);
# Public, encouraged API is exported by default
-@EXPORT = qw (
+our @EXPORT = qw (
encode
decode
encode_utf8
decode_utf8
find_encoding
+ encodings
);
-@EXPORT_OK =
+our @EXPORT_OK =
qw(
- encodings
+ define_encoding
from_to
is_utf8
is_8bit
use Carp;
-# The global hash is declared in XS code
-$encoding{Unicode} = bless({},'Encode::Unicode');
-$encoding{utf8} = bless({},'Encode::utf8');
-$encoding{'iso10646-1'} = bless({},'Encode::iso10646_1');
+our $ON_EBCDIC = (ord("A") == 193);
-sub encodings
-{
- my ($class) = @_;
- foreach my $dir (@INC)
- {
- if (opendir(my $dh,"$dir/Encode"))
- {
- while (defined(my $name = readdir($dh)))
- {
- if ($name =~ /^(.*)\.enc$/)
- {
- next if exists $encoding{$1};
- $encoding{$1} = "$dir/$name";
- }
- }
- closedir($dh);
- }
- }
- return keys %encoding;
-}
+use Encode::Alias;
-sub loadEncoding
-{
- my ($class,$name,$file) = @_;
- if (open(my $fh,$file))
- {
- my $type;
- while (1)
- {
- my $line = <$fh>;
- $type = substr($line,0,1);
- last unless $type eq '#';
- }
- $class .= ('::'.(($type eq 'E') ? 'Escape' : 'Table'));
- #warn "Loading $file";
- return $class->read($fh,$name,$type);
- }
- else
- {
- return undef;
- }
-}
+# Make a %Encoding package variable to allow a certain amount of cheating
+our %Encoding;
+our %ExtModule;
-sub getEncoding
-{
- my ($class,$name) = @_;
- my $enc;
- unless (ref($enc = $encoding{$name}))
- {
- $enc = $class->loadEncoding($name,$enc) if defined $enc;
- unless (ref($enc))
- {
- foreach my $dir (@INC)
- {
- last if ($enc = $class->loadEncoding($name,"$dir/Encode/$name.enc"));
- }
- }
- $encoding{$name} = $enc;
- }
- return $enc;
-}
+my @codepages = qw(
+ 37 424 437 500 737 775 850 852 855
+ 856 857 860 861 862 863 864 865 866
+ 869 874 875 932 936 949 950 1006 1026
+ 1047 1250 1251 1252 1253 1254 1255 1256 1257
+ 1258
+ );
-sub find_encoding
-{
- my ($name) = @_;
- return __PACKAGE__->getEncoding($name);
-}
+my @macintosh = qw(
+ CentralEurRoman Croatian Cyrillic Greek
+ Iceland Roman Rumanian Sami
+ Thai Turkish Ukrainian
+ );
-sub encode
-{
- my ($name,$string,$check) = @_;
- my $enc = find_encoding($name);
- croak("Unknown encoding '$name'") unless defined $enc;
- my $octets = $enc->fromUnicode($string,$check);
- return undef if ($check && length($string));
- return $octets;
+for my $k (2..11,13..16){
+ $ExtModule{"iso-8859-$k"} = 'Encode/Byte.pm';
}
-sub decode
-{
- my ($name,$octets,$check) = @_;
- my $enc = find_encoding($name);
- croak("Unknown encoding '$name'") unless defined $enc;
- my $string = $enc->toUnicode($octets,$check);
- return undef if ($check && length($octets));
- return $string;
+for my $k (@codepages){
+ $ExtModule{"cp$k"} = 'Encode/Byte.pm';
}
-sub from_to
-{
- my ($string,$from,$to,$check) = @_;
- my $f = find_encoding($from);
- croak("Unknown encoding '$from'") unless defined $f;
- my $t = find_encoding($to);
- croak("Unknown encoding '$to'") unless defined $t;
- my $uni = $f->toUnicode($string,$check);
- return undef if ($check && length($string));
- $string = $t->fromUnicode($uni,$check);
- return undef if ($check && length($uni));
- return length($_[0] = $string);
-}
-
-sub encode_utf8
+for my $k (@macintosh)
{
- my ($str) = @_;
- utf8_encode($str);
- return $str;
+ $ExtModule{"mac$k"} = 'Encode/Byte.pm';
}
-sub decode_utf8
-{
- my ($str) = @_;
- return undef unless utf8_decode($str);
- return $str;
-}
-
-package Encode::Unicode;
-
-# Dummy package that provides the encode interface but leaves data
-# as UTF-8 encoded. It is here so that from_to() works.
-
-sub name { 'Unicode' }
-
-sub toUnicode
-{
- my ($obj,$str,$chk) = @_;
- Encode::utf8_upgrade($str);
- $_[1] = '' if $chk;
- return $str;
-}
-
-*fromUnicode = \&toUnicode;
-
-package Encode::utf8;
-
-# package to allow long-hand
-# $octets = encode( utf8 => $string );
-#
-
-sub name { 'utf8' }
-
-sub toUnicode
-{
- my ($obj,$octets,$chk) = @_;
- my $str = Encode::decode_utf8($octets);
- if (defined $str)
- {
- $_[1] = '' if $chk;
- return $str;
- }
- return undef;
-}
+%ExtModule =
+ (%ExtModule,
+ 'koi8-r' => 'Encode/Byte.pm',
+ 'posix-bc' => 'Encode/EBCDIC.pm',
+ cp037 => 'Encode/EBCDIC.pm',
+ cp1026 => 'Encode/EBCDIC.pm',
+ cp1047 => 'Encode/EBCDIC.pm',
+ cp500 => 'Encode/EBCDIC.pm',
+ cp875 => 'Encode/EBCDIC.pm',
+ dingbats => 'Encode/Symbol.pm',
+ macDingbats => 'Encode/Symbol.pm',
+ macSymbol => 'Encode/Symbol.pm',
+ symbol => 'Encode/Symbol.pm',
+ viscii => 'Encode/Byte.pm',
+);
-sub fromUnicode
-{
- my ($obj,$string,$chk) = @_;
- my $octets = Encode::encode_utf8($string);
- $_[1] = '' if $chk;
- return $octets;
+unless ($ON_EBCDIC) { # CJK added to autoload unless EBCDIC env
+%ExtModule =
+ (%ExtModule,
+
+ 'cp936' => 'Encode/CN.pm',
+ 'euc-cn' => 'Encode/CN.pm',
+ 'gb12345-raw' => 'Encode/CN.pm',
+ 'gb2312-raw' => 'Encode/CN.pm',
+ 'gbk' => 'Encode/CN.pm',
+ 'iso-ir-165' => 'Encode/CN.pm',
+
+ '7bit-jis' => 'Encode/JP.pm',
+ 'cp932' => 'Encode/JP.pm',
+ 'euc-jp' => 'Encode/JP.pm',
+ 'iso-2022-jp' => 'Encode/JP.pm',
+ 'iso-2022-jp-1' => 'Encode/JP.pm',
+ 'jis0201-raw' => 'Encode/JP.pm',
+ 'jis0208-raw' => 'Encode/JP.pm',
+ 'jis0212-raw' => 'Encode/JP.pm',
+ 'macJapanese' => 'Encode/JP.pm',
+ 'shiftjis' => 'Encode/JP.pm',
+
+ 'cp949' => 'Encode/KR.pm',
+ 'euc-kr' => 'Encode/KR.pm',
+ 'ksc5601' => 'Encode/KR.pm',
+ 'macKorean' => 'Encode/KR.pm',
+
+ 'big5' => 'Encode/TW.pm',
+ 'big5-hkscs' => 'Encode/TW.pm',
+ 'cp950' => 'Encode/TW.pm',
+
+ 'big5plus' => 'Encode/HanExtra.pm',
+ 'euc-tw' => 'Encode/HanExtra.pm',
+ 'gb18030' => 'Encode/HanExtra.pm',
+ );
}
-package Encode::Table;
-
-sub read
+sub encodings
{
- my ($class,$fh,$name,$type) = @_;
- my $rep = $class->can("rep_$type");
- my ($def,$sym,$pages) = split(/\s+/,scalar(<$fh>));
- my @touni;
- my %fmuni;
- my $count = 0;
- $def = hex($def);
- while ($pages--)
- {
- my $line = <$fh>;
- chomp($line);
- my $page = hex($line);
- my @page;
- my $ch = $page * 256;
- for (my $i = 0; $i < 16; $i++)
+ my $class = shift;
+ my @modules = (@_ and $_[0] eq ":all") ? values %ExtModule : @_;
+ for my $m (@modules)
{
- my $line = <$fh>;
- for (my $j = 0; $j < 16; $j++)
- {
- my $val = hex(substr($line,0,4,''));
- if ($val || !$ch)
- {
- my $uch = chr($val);
- push(@page,$uch);
- $fmuni{$uch} = $ch;
- $count++;
- }
- else
- {
- push(@page,undef);
- }
- $ch++;
- }
+ $DEBUG and warn "about to require $m;";
+ eval { require $m; };
}
- $touni[$page] = \@page;
- }
-
- return bless {Name => $name,
- Rep => $rep,
- ToUni => \@touni,
- FmUni => \%fmuni,
- Def => $def,
- Num => $count,
- },$class;
+ return
+ map({$_->[0]}
+ sort({$a->[1] cmp $b->[1]}
+ map({[$_, lc $_]}
+ grep({ $_ ne 'Internal' } keys %Encoding))));
}
-sub name { shift->{'Name'} }
-
-sub rep_S { 'C' }
-
-sub rep_D { 'n' }
-
-sub rep_M { ($_[0] > 255) ? 'n' : 'C' }
-
-sub representation
+sub define_encoding
{
- my ($obj,$ch) = @_;
- $ch = 0 unless @_ > 1;
- $obj-{'Rep'}->($ch);
+ my $obj = shift;
+ my $name = shift;
+ $Encoding{$name} = $obj;
+ my $lc = lc($name);
+ define_alias($lc => $obj) unless $lc eq $name;
+ while (@_)
+ {
+ my $alias = shift;
+ define_alias($alias,$obj);
+ }
+ return $obj;
}
-sub toUnicode
+sub getEncoding
{
- my ($obj,$str,$chk) = @_;
- my $rep = $obj->{'Rep'};
- my $touni = $obj->{'ToUni'};
- my $uni = '';
- while (length($str))
- {
- my $ch = ord(substr($str,0,1,''));
- my $x;
- if (&$rep($ch) eq 'C')
+ my ($class,$name,$skip_external) = @_;
+ my $enc;
+ if (ref($name) && $name->can('new_sequence'))
{
- $x = $touni->[0][$ch];
+ return $name;
}
- else
+ my $lc = lc $name;
+ if (exists $Encoding{$name})
{
- $x = $touni->[$ch][ord(substr($str,0,1,''))];
+ return $Encoding{$name};
}
- unless (defined $x)
+ if (exists $Encoding{$lc})
{
- last if $chk;
- # What do we do here ?
- $x = '';
+ return $Encoding{$lc};
}
- $uni .= $x;
- }
- $_[1] = $str if $chk;
- return $uni;
-}
-sub fromUnicode
-{
- my ($obj,$uni,$chk) = @_;
- my $fmuni = $obj->{'FmUni'};
- my $str = '';
- my $def = $obj->{'Def'};
- my $rep = $obj->{'Rep'};
- while (length($uni))
- {
- my $ch = substr($uni,0,1,'');
- my $x = $fmuni->{chr(ord($ch))};
- unless (defined $x)
+ my $oc = $class->find_alias($name);
+ return $oc if defined $oc;
+
+ $oc = $class->find_alias($lc) if $lc ne $name;
+ return $oc if defined $oc;
+
+ if (!$skip_external and exists $ExtModule{$lc})
{
- last if ($chk);
- $x = $def;
+ eval{ require $ExtModule{$lc}; };
+ return $Encoding{$name} if exists $Encoding{$name};
}
- $str .= pack(&$rep($x),$x);
- }
- $_[1] = $uni if $chk;
- return $str;
-}
-package Encode::iso10646_1;
-# Encoding is 16-bit network order Unicode
-# Used for X font encodings
-
-sub name { 'iso10646-1' }
+ return;
+}
-sub toUnicode
+sub find_encoding
{
- my ($obj,$str,$chk) = @_;
- my $uni = '';
- while (length($str))
- {
- my $code = unpack('n',substr($str,0,2,'')) & 0xffff;
- $uni .= chr($code);
- }
- $_[1] = $str if $chk;
- Encode::utf8_upgrade($uni);
- return $uni;
+ my ($name,$skip_external) = @_;
+ return __PACKAGE__->getEncoding($name,$skip_external);
}
-sub fromUnicode
+sub encode
{
- my ($obj,$uni,$chk) = @_;
- my $str = '';
- while (length($uni))
- {
- my $ch = substr($uni,0,1,'');
- my $x = ord($ch);
- unless ($x < 32768)
- {
- last if ($chk);
- $x = 0;
- }
- $str .= pack('n',$x);
- }
- $_[1] = $uni if $chk;
- return $str;
+ my ($name,$string,$check) = @_;
+ my $enc = find_encoding($name);
+ croak("Unknown encoding '$name'") unless defined $enc;
+ my $octets = $enc->encode($string,$check);
+ return undef if ($check && length($string));
+ return $octets;
}
-
-package Encode::Escape;
-use Carp;
-
-sub read
+sub decode
{
- my ($class,$fh,$name) = @_;
- my %self = (Name => $name, Num => 0);
- while (<$fh>)
- {
- my ($key,$val) = /^(\S+)\s+(.*)$/;
- $val =~ s/^\{(.*?)\}/$1/g;
- $val =~ s/\\x([0-9a-f]{2})/chr(hex($1))/ge;
- $self{$key} = $val;
- }
- return bless \%self,$class;
+ my ($name,$octets,$check) = @_;
+ my $enc = find_encoding($name);
+ croak("Unknown encoding '$name'") unless defined $enc;
+ my $string = $enc->decode($octets,$check);
+ $_[1] = $octets if $check;
+ return $string;
}
-sub name { shift->{'Name'} }
+sub from_to
+{
+ my ($string,$from,$to,$check) = @_;
+ my $f = find_encoding($from);
+ croak("Unknown encoding '$from'") unless defined $f;
+ my $t = find_encoding($to);
+ croak("Unknown encoding '$to'") unless defined $t;
+ my $uni = $f->decode($string,$check);
+ return undef if ($check && length($string));
+ $string = $t->encode($uni,$check);
+ return undef if ($check && length($uni));
+ return defined($_[0] = $string) ? length($string) : undef ;
+}
-sub toUnicode
+sub encode_utf8
{
- croak("Not implemented yet");
+ my ($str) = @_;
+ utf8::encode($str);
+ return $str;
}
-sub fromUnicode
+sub decode_utf8
{
- croak("Not implemented yet");
+ my ($str) = @_;
+ return undef unless utf8::decode($str);
+ return $str;
}
-# switch back to Encode package in case we ever add AutoLoader
-package Encode;
+predefine_encodings();
+
+#
+# This is to restore %Encoding if really needed;
+#
+sub predefine_encodings{
+ if ($ON_EBCDIC) {
+ # was in Encode::UTF_EBCDIC
+ package Encode::UTF_EBCDIC;
+ *name = sub{ shift->{'Name'} };
+ *new_sequence = sub{ return $_[0] };
+ *decode = sub{
+ my ($obj,$str,$chk) = @_;
+ my $res = '';
+ for (my $i = 0; $i < length($str); $i++) {
+ $res .=
+ chr(utf8::unicode_to_native(ord(substr($str,$i,1))));
+ }
+ $_[1] = '' if $chk;
+ return $res;
+ };
+ *encode = sub{
+ my ($obj,$str,$chk) = @_;
+ my $res = '';
+ for (my $i = 0; $i < length($str); $i++) {
+ $res .=
+ chr(utf8::native_to_unicode(ord(substr($str,$i,1))));
+ }
+ $_[1] = '' if $chk;
+ return $res;
+ };
+ $Encode::Encoding{Unicode} =
+ bless {Name => "UTF_EBCDIC"}, "Encode::UTF_EBCDIC";
+ } else {
+ # was in Encode::UTF_EBCDIC
+ package Encode::Internal;
+ *name = sub{ shift->{'Name'} };
+ *new_sequence = sub{ return $_[0] };
+ *decode = sub{
+ my ($obj,$str,$chk) = @_;
+ utf8::upgrade($str);
+ $_[1] = '' if $chk;
+ return $str;
+ };
+ *encode = \&decode;
+ $Encode::Encoding{Unicode} =
+ bless {Name => "Internal"}, "Encode::Internal";
+ }
+
+ {
+ # was in Encode::utf8
+ package Encode::utf8;
+ *name = sub{ shift->{'Name'} };
+ *new_sequence = sub{ return $_[0] };
+ *decode = sub{
+ my ($obj,$octets,$chk) = @_;
+ my $str = Encode::decode_utf8($octets);
+ if (defined $str) {
+ $_[1] = '' if $chk;
+ return $str;
+ }
+ return undef;
+ };
+ *encode = sub {
+ my ($obj,$string,$chk) = @_;
+ my $octets = Encode::encode_utf8($string);
+ $_[1] = '' if $chk;
+ return $octets;
+ };
+ $Encode::Encoding{utf8} =
+ bless {Name => "utf8"}, "Encode::utf8";
+ }
+ # do externals if necessary
+ require File::Basename;
+ require File::Spec;
+ for my $ext (qw(Unicode)){
+ my $pm =
+ File::Spec->catfile(File::Basename::dirname($INC{'Encode.pm'}),
+ "Encode", "$ext.pm");
+ do $pm;
+ }
+}
+
+require Encode::Encoding;
+require Encode::XS;
1;
use Encode;
+
+=head2 Table of Contents
+
+Encode consists of a collection of modules which details are too big
+to fit in one document. This POD itself explains the top-level APIs
+and general topics at a glance. For other topics and more details,
+see the PODs below;
+
+ Name Description
+ --------------------------------------------------------
+ Encode::Alias Alias defintions to encodings
+ Encode::Encoding Encode Implementation Base Class
+ Encode::Supported List of Supported Encodings
+ Encode::CN Simplified Chinese Encodings
+ Encode::JP Japanese Encodings
+ Encode::KR Korean Encodings
+ Encode::TW Traditional Chinese Encodings
+ --------------------------------------------------------
+
=head1 DESCRIPTION
-The C<Encode> module provides the interfaces between perl's strings
-and the rest of the system. Perl strings are sequences of B<characters>.
+The C<Encode> module provides the interfaces between Perl's strings
+and the rest of the system. Perl strings are sequences of
+B<characters>.
The repertoire of characters that Perl can represent is at least that
-defined by the Unicode Consortium. On most platforms the ordinal values
-of the characters (as returned by C<ord(ch)>) is the "Unicode codepoint" for
-the character (the exceptions are those platforms where the legacy
-encoding is some variant of EBCDIC rather than a super-set of ASCII
-- see L<perlebcdic>).
+defined by the Unicode Consortium. On most platforms the ordinal
+values of the characters (as returned by C<ord(ch)>) is the "Unicode
+codepoint" for the character (the exceptions are those platforms where
+the legacy encoding is some variant of EBCDIC rather than a super-set
+of ASCII - see L<perlebcdic>).
-Traditionaly computer data has been moved around in 8-bit chunks
+Traditionally computer data has been moved around in 8-bit chunks
often called "bytes". These chunks are also known as "octets" in
-networking standards. Perl is widely used to manipulate data of
-many types - not only strings of characters representing human or
-computer languages but also "binary" data being the machines representation
-of numbers, pixels in an image - or just about anything.
+networking standards. Perl is widely used to manipulate data of many
+types - not only strings of characters representing human or computer
+languages but also "binary" data being the machines representation of
+numbers, pixels in an image - or just about anything.
-When perl is processing "binary data" the programmer wants perl to process
-"sequences of bytes". This is not a problem for perl - as a byte has 256
-possible values it easily fits in perl's much larger "logical character".
+When Perl is processing "binary data" the programmer wants Perl to
+process "sequences of bytes". This is not a problem for Perl - as a
+byte has 256 possible values it easily fits in Perl's much larger
+"logical character".
=head2 TERMINOLOGY
-=over
+=over 4
=item *
I<character>: a character in the range 0..(2**32-1) (or more).
-(What perl's strings are made of.)
+(What Perl's strings are made of.)
=item *
I<byte>: a character in the range 0..255
-(A special case of a perl character.)
+(A special case of a Perl character.)
=item *
I<octet>: 8 bits of data, with ordinal values 0..255
-(Term for bytes passed to or from a non-perl context, e.g. disk file.)
+(Term for bytes passed to or from a non-Perl context, e.g. disk file.)
=back
general meant only for those who think they know what they are doing,
and such details may change in future releases.
-=head1 ENCODINGS
-
-=head2 Characteristics of an Encoding
-
-An encoding has a "repertoire" of characters that it can represent,
-and for each representable character there is at least one sequence of
-octets that represents it.
-
-=head2 Types of Encodings
-
-Encodings can be divided into the following types:
-
-=over 4
-
-=item * Fixed length 8-bit (or less) encodings.
-
-Each character is a single octet so may have a repertoire of up to
-256 characters. ASCII and iso-8859-* are typical examples.
-
-=item * Fixed length 16-bit encodings
-
-Each character is two octets so may have a repertoire of up to
-65,536 characters. Unicode's UCS-2 is an example. Also used for
-encodings for East Asian languages.
-
-=item * Fixed length 32-bit encodings.
-
-Not really very "encoded" encodings. The Unicode code points
-are just represented as 4-octet integers. None the less because
-different architectures use different representations of integers
-(so called "endian") there at least two disctinct encodings.
-
-=item * Multi-byte encodings
-
-The number of octets needed to represent a character varies.
-UTF-8 is a particularly complex but regular case of a multi-byte
-encoding. Several East Asian countries use a multi-byte encoding
-where 1-octet is used to cover western roman characters and Asian
-characters get 2-octets.
-(UTF-16 is strictly a multi-byte encoding taking either 2 or 4 octets
-to represent a Unicode code point.)
-
-=item * "Escape" encodings.
-
-These encodings embed "escape sequences" into the octet sequence
-which describe how the following octets are to be interpreted.
-The iso-2022-* family is typical. Following the escape sequence
-octets are encoded by an "embedded" encoding (which will be one
-of the above types) until another escape sequence switches to
-a different "embedded" encoding.
-
-These schemes are very flexible and can handle mixed languages but are
-very complex to process (and have state).
-No escape encodings are implemented for perl yet.
-
-=back
-
-=head2 Specifying Encodings
-
-Encodings can be specified to the API described below in two ways:
-
-=over 4
-
-=item 1. By name
-
-Encoding names are strings with characters taken from a restricted repertoire.
-See L</"Encoding Names">.
-
-=item 2. As an object
-
-Encoding objects are returned by C<find_encoding($name)>.
-
-=back
-
-=head2 Encoding Names
-
-Encoding names are case insensitive. White space in names is ignored.
-In addition an encoding may have aliases. Each encoding has one "canonical" name.
-The "canonical" name is chosen from the names of the encoding by picking
-the first in the following sequence:
-
-=over 4
-
-=item * The MIME name as defined in IETF RFC-XXXX.
-
-=item * The name in the IANA registry.
-
-=item * The name used by the the organization that defined it.
-
-=back
-
-Because of all the alias issues, and because in the general case
-encodings have state C<Encode> uses the encoding object internally
-once an operation is in progress.
-
-I<Aliasing is not yet implemented.>
-
=head1 PERL ENCODING API
-=head2 Generic Encoding Interface
-
=over 4
-=item *
-
- $bytes = encode(ENCODING, $string[, CHECK])
-
-Encodes string from perl's internal form into I<ENCODING> and returns a
-sequence of octets.
-See L</"Handling Malformed Data">.
-
-=item *
-
- $string = decode(ENCODING, $bytes[, CHECK])
-
-Decode sequence of octets assumed to be in I<ENCODING> into perls internal
-form and returns the resuting string.
-See L</"Handling Malformed Data">.
+=item $octets = encode(ENCODING, $string[, CHECK])
-=back
-
-=head2 Handling Malformed Data
-
-If CHECK is not set, C<undef> is returned. If the data is supposed to
-be UTF-8, an optional lexical warning (category utf8) is given.
-If CHECK is true but not a code reference, dies.
+Encodes string from Perl's internal form into I<ENCODING> and returns
+a sequence of octets. ENCODING can be either a canonical name or
+alias. For encoding names and aliases, see L</"Defining Aliases">.
+For CHECK see L</"Handling Malformed Data">.
-It would desirable to have a way to indicate that transform should use the
-encodings "replacement character" - no such mechanism is defined yet.
+For example to convert (internally UTF-8 encoded) Unicode string to
+iso-8859-1 (also known as Latin1),
-It is also planned to allow I<CHECK> to be a code reference.
-
-This is not yet implemented as there are design issues with what its arguments
-should be and how it returns its results.
-
-=over 4
+ $octets = encode("iso-8859-1", $unicode);
-=item Scheme 1
+=item $string = decode(ENCODING, $octets[, CHECK])
-Passed remaining fragment of string being processed.
-Modifies it in place to remove bytes/characters it can understand
-and returns a string used to represent them.
-e.g.
+Decode sequence of octets assumed to be in I<ENCODING> into Perl's
+internal form and returns the resulting string. as in encode(),
+ENCODING can be either a canonical name or alias. For encoding names
+and aliases, see L</"Defining Aliases">. For CHECK see
+L</"Handling Malformed Data">.
- sub fixup {
- my $ch = substr($_[0],0,1,'');
- return sprintf("\x{%02X}",ord($ch);
- }
+For example to convert ISO-8859-1 data to UTF-8:
-This scheme is close to how underlying C code for Encode works, but gives
-the fixup routine very little context.
+ $utf8 = decode("iso-8859-1", $latin1);
-=item Scheme 2
+=item [$length =] from_to($string, FROM_ENCODING, TO_ENCODING [,CHECK])
-Passed original string, and an index into it of the problem area,
-and output string so far.
-Appends what it will to output string and returns new index into
-original string.
-e.g.
+Convert B<in-place> the data between two encodings. How did the data
+in $string originally get to be in FROM_ENCODING? Either using
+encode() or through PerlIO: See L</"Encoding and IO">.
+For encoding names and aliases, see L</"Defining Aliases">.
+For CHECK see L</"Handling Malformed Data">.
- sub fixup {
- # my ($s,$i,$d) = @_;
- my $ch = substr($_[0],$_[1],1);
- $_[2] .= sprintf("\x{%02X}",ord($ch);
- return $_[1]+1;
- }
+For example to convert ISO-8859-1 data to UTF-8:
-This scheme gives maximal control to the fixup routine but is more complicated
-to code, and may need internals of Encode to be tweaked to keep original
-string intact.
+ from_to($data, "iso-8859-1", "utf-8");
-=item Other Schemes
+and to convert it back:
-Hybrids of above.
+ from_to($data, "utf-8", "iso-8859-1");
-Multiple return values rather than in-place modifications.
+Note that because the conversion happens in place, the data to be
+converted cannot be a string constant, it must be a scalar variable.
-Index into the string could be pos($str) allowing s/\G...//.
+from_to() return the length of the converted string on success, undef
+otherwise.
=back
=head2 UTF-8 / utf8
The Unicode consortium defines the UTF-8 standard as a way of encoding
-the entire Unicode repertiore as sequences of octets. This encoding
-is expected to become very widespread. Perl can use this form internaly
-to represent strings, so conversions to and from this form are particularly
-efficient (as octets in memory do not have to change, just the meta-data
-that tells perl how to treat them).
+the entire Unicode repertoire as sequences of octets. This encoding is
+expected to become very widespread. Perl can use this form internally
+to represent strings, so conversions to and from this form are
+particularly efficient (as octets in memory do not have to change,
+just the meta-data that tells Perl how to treat them).
=over 4
-=item *
-
- $bytes = encode_utf8($string);
+=item $octets = encode_utf8($string);
-The characters that comprise string are encoded in perl's superset of UTF-8
+The characters that comprise string are encoded in Perl's superset of UTF-8
and the resulting octets returned as a sequence of bytes. All possible
characters have a UTF-8 representation so this function cannot fail.
-=item *
+=item $string = decode_utf8($octets [, CHECK]);
- $string = decode_utf8($bytes [,CHECK]);
-
-The sequence of octets represented by $bytes is decoded from UTF-8 into
-a sequence of logical characters. Not all sequences of octets form valid
-UTF-8 encodings, so it is possible for this call to fail.
-See L</"Handling Malformed Data">.
+The sequence of octets represented by $octets is decoded from UTF-8
+into a sequence of logical characters. Not all sequences of octets
+form valid UTF-8 encodings, so it is possible for this call to fail.
+For CHECK see L</"Handling Malformed Data">.
=back
-=head2 Other Encodings of Unicode
+=head2 Listing available encodings
+
+ use Encode;
+ @list = Encode->encodings();
-UTF-16 is similar to UCS-2, 16 bit or 2-byte chunks.
-UCS-2 can only represent 0..0xFFFF, while UTF-16 has a "surogate pair"
-scheme which allows it to cover the whole Unicode range.
+Returns a list of the canonical names of the available encodings that
+are loaded. To get a list of all available encodings including the
+ones that are not loaded yet, say
-Encode implements big-endian UCS-2 as the encoding "iso10646-1" as that
-happens to be the name used by that representation when used with X11 fonts.
+ @all_encodings = Encode->encodings(":all");
-UTF-32 or UCS-4 is 32-bit or 4-byte chunks. Perl's logical characters
-can be considered as being in this form without encoding. An encoding
-to transfer strings in this form (e.g. to write them to a file) would need to
+Or you can give the name of specific module.
- pack('L',map(chr($_),split(//,$string))); # native
- or
- pack('V',map(chr($_),split(//,$string))); # little-endian
- or
- pack('N',map(chr($_),split(//,$string))); # big-endian
+ @with_jp = Encode->encodings("Encode/JP.pm");
-depending on the endian required.
+Note in this case you have to say C<"Encode/JP.pm"> instead of
+C<"Encode::JP">.
-No UTF-32 encodings are not yet implemented.
+To find which encodings are supported by this package in details,
+see L<Encode::Supported>.
-Both UCS-2 and UCS-4 style encodings can have "byte order marks" by representing
-the code point 0xFFFE as the very first thing in a file.
+=head2 Defining Aliases
+
+To add new alias to a given encoding, Use;
+
+ use Encode;
+ use Encode::Alias;
+ define_alias(newName => ENCODING);
+
+After that, newName can be used as an alias for ENCODING.
+ENCODING may be either the name of an encoding or an
+I<encoding object>
+
+See L<Encode::Alias> on details.
=head1 Encoding and IO
It is very common to want to do encoding transformations when
reading or writing files, network connections, pipes etc.
-If perl is configured to use the new 'perlio' IO system then
+If Perl is configured to use the new 'perlio' IO system then
C<Encode> provides a "layer" (See L<perliol>) which can transform
data as it is read or written.
- open(my $ilyad,'>:encoding(iso8859-7)','ilyad.greek');
- print $ilyad @epic;
+Here is how the blind poet would modernise the encoding:
+
+ use Encode;
+ open(my $iliad,'<:encoding(iso-8859-7)','iliad.greek');
+ open(my $utf8,'>:utf8','iliad.utf8');
+ my @epic = <$iliad>;
+ print $utf8 @epic;
+ close($utf8);
+ close($illiad);
In addition the new IO system can also be configured to read/write
UTF-8 encoded characters (as noted above this is efficient):
- open(my $fh,'>:utf8','anything');
- print $fh "Any \x{0021} string \N{SMILEY FACE}\n";
+ open(my $fh,'>:utf8','anything');
+ print $fh "Any \x{0021} string \N{SMILEY FACE}\n";
Either of the above forms of "layer" specifications can be made the default
for a lexical scope with the C<use open ...> pragma. See L<open>.
Once a handle is open is layers can be altered using C<binmode>.
-Without any such configuration, or if perl itself is built using
+Without any such configuration, or if Perl itself is built using
system's own IO, then write operations assume that file handle accepts
only I<bytes> and will C<die> if a character larger than 255 is
written to the handle. When reading, each octet from the handle
becomes a byte-in-a-character. Note that this default is the same
-behaviour as bytes-only languages (including perl before v5.6) would have,
-and is sufficient to handle native 8-bit encodings e.g. iso-8859-1,
-EBCDIC etc. and any legacy mechanisms for handling other encodings
-and binary data.
+behaviour as bytes-only languages (including Perl before v5.6) would
+have, and is sufficient to handle native 8-bit encodings
+e.g. iso-8859-1, EBCDIC etc. and any legacy mechanisms for handling
+other encodings and binary data.
-In other cases it is the programs responsibility
-to transform characters into bytes using the API above before
-doing writes, and to transform the bytes read from a handle into characters
-before doing "character operations" (e.g. C<lc>, C</\W+/>, ...).
+In other cases it is the programs responsibility to transform
+characters into bytes using the API above before doing writes, and to
+transform the bytes read from a handle into characters before doing
+"character operations" (e.g. C<lc>, C</\W+/>, ...).
-=head1 Encoding How to ...
+You can also use PerlIO to convert larger amounts of data you don't
+want to bring into memory. For example to convert between ISO-8859-1
+(Latin 1) and UTF-8 (or UTF-EBCDIC in EBCDIC machines):
-To do:
+ open(F, "<:encoding(iso-8859-1)", "data.txt") or die $!;
+ open(G, ">:utf8", "data.utf") or die $!;
+ while (<F>) { print G }
-=over 4
+ # Could also do "print G <F>" but that would pull
+ # the whole file into memory just to write it out again.
-=item * IO with mixed content (faking iso-2020-*)
+More examples:
-=item * MIME's Content-Length:
+ open(my $f, "<:encoding(cp1252)")
+ open(my $g, ">:encoding(iso-8859-2)")
+ open(my $h, ">:encoding(latin9)") # iso-8859-15
-=item * UTF-8 strings in binary data.
+See L<PerlIO> for more information.
-=item * perl/Encode wrappers on non-Unicode XS modules.
+See also L<encoding> for how to change the default encoding of the
+data in your script.
-=back
+=head1 Handling Malformed Data
-=head1 Messing with Perl's Internals
+If I<CHECK> is not set, (en|de)code will put I<substitution character> in
+place of the malformed character. for UCM-based encodings,
+E<lt>subcharE<gt> will be used. For Unicode, \xFFFD is used. If the
+data is supposed to be UTF-8, an optional lexical warning (category
+utf8) is given.
-The following API uses parts of perl's internals in the current implementation.
-As such they are efficient, but may change.
+If I<CHECK> is true but not a code reference, dies with an error message.
-=over 4
+In future you will be able to use a code reference to a callback
+function for the value of I<CHECK> but its API is still undecided.
-=item *
+=head1 Defining Encodings
- $num_octets = utf8_upgrade($string);
+To define a new encoding, use:
-Converts internal representation of string to the UTF-8 form.
-Returns the number of octets necessary to represent the string as UTF-8.
+ use Encode qw(define_alias);
+ define_encoding($object, 'canonicalName' [, alias...]);
-=item * utf8_downgrade($string[, CHECK])
+I<canonicalName> will be associated with I<$object>. The object
+should provide the interface described in L<Encode::Encoding>
+If more than two arguments are provided then additional
+arguments are taken as aliases for I<$object> as for C<define_alias>.
-Converts internal representation of string to be un-encoded bytes.
+See L<Encode::Encoding> for more details.
-=item * is_utf8(STRING [, CHECK])
+=head1 Messing with Perl's Internals
-[INTERNAL] Test whether the UTF-8 flag is turned on in the STRING.
-If CHECK is true, also checks the data in STRING for being
-well-formed UTF-8. Returns true if successful, false otherwise.
+The following API uses parts of Perl's internals in the current
+implementation. As such they are efficient, but may change.
-=item * valid_utf8(STRING)
+=over 4
-[INTERNAL] Test whether STRING is in a consistent state.
-Will return true if string is held as bytes, or is well-formed UTF-8
-and has the UTF-8 flag on.
-Main reason for this routine is to allow perl's testsuite to check
-that operations have left strings in a consistent state.
+=item is_utf8(STRING [, CHECK])
-=item *
+[INTERNAL] Test whether the UTF-8 flag is turned on in the STRING.
+If CHECK is true, also checks the data in STRING for being well-formed
+UTF-8. Returns true if successful, false otherwise.
- _utf8_on(STRING)
+=item _utf8_on(STRING)
[INTERNAL] Turn on the UTF-8 flag in STRING. The data in STRING is
B<not> checked for being well-formed UTF-8. Do not use unless you
state of the UTF-8 flag (so please don't test the return value as
I<not> success or failure), or C<undef> if STRING is not a string.
-=item *
-
- _utf8_off(STRING)
+=item _utf8_off(STRING)
[INTERNAL] Turn off the UTF-8 flag in STRING. Do not use frivolously.
Returns the previous state of the UTF-8 flag (so please don't test the
=head1 SEE ALSO
-L<perlunicode>, L<perlebcdic>, L<perlfunc/open>
+L<Encode::Encoding>,
+L<Encode::Supported>,
+L<PerlIO>,
+L<encoding>,
+L<perlebcdic>,
+L<perlfunc/open>,
+L<perlunicode>,
+L<utf8>,
+the Perl Unicode Mailing List E<lt>perl-unicode@perl.orgE<gt>
=cut
-
-
-