X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=ext%2FEncode%2FEncode.pm;h=bdfa69572315fecf436290a02f1ac238a401760d;hb=92a665d639a42192198e801676cccae0bd9afa83;hp=7886c6382637d976d0a7160ce8818262036a5b18;hpb=071db25d4bd6237e4ead7e44b9c1420448a117ff;p=p5sagit%2Fp5-mst-13.2.git diff --git a/ext/Encode/Encode.pm b/ext/Encode/Encode.pm index 7886c63..bdfa695 100644 --- a/ext/Encode/Encode.pm +++ b/ext/Encode/Encode.pm @@ -1,220 +1,317 @@ +# +# $Id: Encode.pm,v 2.18 2006/06/03 20:28:48 dankogai Exp dankogai $ +# package Encode; use strict; -our $VERSION = do { my @r = (q$Revision: 0.97 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; -our $DEBUG = 0; +use warnings; +our $VERSION = "2.18_01"; +sub DEBUG () { 0 } +use XSLoader (); +XSLoader::load( __PACKAGE__, $VERSION ); -require DynaLoader; require Exporter; - -our @ISA = qw(Exporter DynaLoader); +use base qw/Exporter/; # Public, encouraged API is exported by default -our @EXPORT = qw ( - encode - decode - encode_utf8 - decode_utf8 - find_encoding - encodings -); -our @EXPORT_OK = +our @EXPORT = qw( + decode decode_utf8 encode encode_utf8 str2bytes bytes2str + encodings find_encoding clone_encoding +); +our @FB_FLAGS = qw( + DIE_ON_ERR WARN_ON_ERR RETURN_ON_ERR LEAVE_SRC + PERLQQ HTMLCREF XMLCREF STOP_AT_PARTIAL +); +our @FB_CONSTS = qw( + FB_DEFAULT FB_CROAK FB_QUIET FB_WARN + FB_PERLQQ FB_HTMLCREF FB_XMLCREF +); +our @EXPORT_OK = ( qw( - define_encoding - from_to - is_utf8 - is_8bit - is_16bit - utf8_upgrade - utf8_downgrade - _utf8_on - _utf8_off - ); - -bootstrap Encode (); + _utf8_off _utf8_on define_encoding from_to is_16bit is_8bit + is_utf8 perlio_ok resolve_alias utf8_downgrade utf8_upgrade + ), + @FB_FLAGS, @FB_CONSTS, +); + +our %EXPORT_TAGS = ( + all => [ @EXPORT, @EXPORT_OK ], + fallbacks => [@FB_CONSTS], + fallback_all => [ @FB_CONSTS, @FB_FLAGS ], +); # Documentation moved after __END__ for speed - NI-S -use Carp; +our $ON_EBCDIC = ( ord("A") == 193 ); use Encode::Alias; # Make a %Encoding package variable to allow a certain amount of cheating our %Encoding; +our %ExtModule; +require Encode::Config; +eval { require Encode::ConfigLocal }; -our %ExtModule = - ( - viscii => 'Encode/Byte.pm', - 'koi8-r' => 'Encode/Byte.pm', - cp1047 => 'Encode/EBCDIC.pm', - cp37 => 'Encode/EBCDIC.pm', - 'posix-bc' => 'Encode/EBCDIC.pm', - symbol => 'Encode/Symbol.pm', - dingbats => 'Encode/Symbol.pm', - 'euc-cn' => 'Encode/CN.pm', - gb2312 => 'Encode/CN.pm', - gb12345 => 'Encode/CN.pm', - gbk => 'Encode/CN.pm', - cp936 => 'Encode/CN.pm', - 'iso-ir-165' => 'Encode/CN.pm', - 'euc-jp' => 'Encode/JP.pm', - 'iso-2022-jp' => 'Encode/JP.pm', - '7bit-jis' => 'Encode/JP.pm', - shiftjis => 'Encode/JP.pm', - macjapan => 'Encode/JP.pm', - cp932 => 'Encode/JP.pm', - 'euc-kr' => 'Encode/KR.pm', - ksc5601 => 'Encode/KR.pm', - cp949 => 'Encode/KR.pm', - big5 => 'Encode/TW.pm', - 'big5-hkscs' => 'Encode/TW.pm', - cp950 => 'Encode/TW.pm', - gb18030 => 'Encode/HanExtra.pm', - big5plus => 'Encode/HanExtra.pm', - 'euc-tw' => 'Encode/HanExtra.pm', - ); - -for my $k (2..11,13..16){ - $ExtModule{"iso-8859-$k"} = 'Encode/Byte.pm'; -} - -for my $k (1250..1258){ - $ExtModule{"cp$k"} = 'Encode/Byte.pm'; -} - -for my $k (qw(centeuro croatian cyrillic dingbats greek - iceland roman rumanian sami - thai turkish ukraine)) -{ - $ExtModule{"mac$k"} = 'Encode/Byte.pm'; -} - - -sub encodings -{ +sub encodings { my $class = shift; - my @modules = (@_ and $_[0] eq ":all") ? values %ExtModule : @_; - for my $m (@modules) - { - $DEBUG and warn "about to require $m;"; - eval { require $m; }; + my %enc; + if ( @_ and $_[0] eq ":all" ) { + %enc = ( %Encoding, %ExtModule ); + } + else { + %enc = %Encoding; + for my $mod ( map { m/::/o ? $_ : "Encode::$_" } @_ ) { + DEBUG and warn $mod; + for my $enc ( keys %ExtModule ) { + $ExtModule{$enc} eq $mod and $enc{$enc} = $mod; + } + } } - return - map({$_->[0]} - sort({$a->[1] cmp $b->[1]} - map({[$_, lc $_]} - grep({ $_ ne 'Internal' } keys %Encoding)))); + return sort { lc $a cmp lc $b } + grep { !/^(?:Internal|Unicode|Guess)$/o } keys %enc; +} + +sub perlio_ok { + my $obj = ref( $_[0] ) ? $_[0] : find_encoding( $_[0] ); + $obj->can("perlio_ok") and return $obj->perlio_ok(); + return 0; # safety net } -sub define_encoding -{ +sub define_encoding { 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); + define_alias( $lc => $obj ) unless $lc eq $name; + while (@_) { + my $alias = shift; + define_alias( $alias, $obj ); } return $obj; } -sub getEncoding -{ - my ($class,$name,$skip_external) = @_; - my $enc; - if (ref($name) && $name->can('new_sequence')) - { - return $name; - } +sub getEncoding { + my ( $class, $name, $skip_external ) = @_; + + ref($name) && $name->can('renew') and return $name; + exists $Encoding{$name} and return $Encoding{$name}; my $lc = lc $name; - if (exists $Encoding{$name}) - { - return $Encoding{$name}; - } - if (exists $Encoding{$lc}) - { - return $Encoding{$lc}; - } + exists $Encoding{$lc} and return $Encoding{$lc}; 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}) - { - eval{ require $ExtModule{$lc}; }; - return $Encoding{$name} if exists $Encoding{$name}; + defined($oc) and return $oc; + $lc ne $name and $oc = $class->find_alias($lc); + defined($oc) and return $oc; + + unless ($skip_external) { + if ( my $mod = $ExtModule{$name} || $ExtModule{$lc} ) { + $mod =~ s,::,/,g; + $mod .= '.pm'; + eval { require $mod; }; + exists $Encoding{$name} and return $Encoding{$name}; + } } + return; +} +sub find_encoding($;$) { + my ( $name, $skip_external ) = @_; + return __PACKAGE__->getEncoding( $name, $skip_external ); +} + +sub resolve_alias($) { + my $obj = find_encoding(shift); + defined $obj and return $obj->name; return; } -sub find_encoding -{ - my ($name,$skip_external) = @_; - return __PACKAGE__->getEncoding($name,$skip_external); +sub clone_encoding($) { + my $obj = find_encoding(shift); + ref $obj or return; + eval { require Storable }; + $@ and return; + return Storable::dclone($obj); } -sub encode -{ - my ($name,$string,$check) = @_; +sub encode($$;$) { + my ( $name, $string, $check ) = @_; + return undef unless defined $string; + $string .= '' if ref $string; # stringify; + $check ||= 0; my $enc = find_encoding($name); - croak("Unknown encoding '$name'") unless defined $enc; - my $octets = $enc->encode($string,$check); - return undef if ($check && length($string)); + unless ( defined $enc ) { + require Carp; + Carp::croak("Unknown encoding '$name'"); + } + my $octets = $enc->encode( $string, $check ); + $_[1] = $string if $check and !( $check & LEAVE_SRC() ); return $octets; } +*str2bytes = \&encode; -sub decode -{ - my ($name,$octets,$check) = @_; +sub decode($$;$) { + my ( $name, $octets, $check ) = @_; + return undef unless defined $octets; + $octets .= '' if ref $octets; + $check ||= 0; my $enc = find_encoding($name); - croak("Unknown encoding '$name'") unless defined $enc; - my $string = $enc->decode($octets,$check); - $_[1] = $octets if $check; + unless ( defined $enc ) { + require Carp; + Carp::croak("Unknown encoding '$name'"); + } + my $string = $enc->decode( $octets, $check ); + $_[1] = $octets if $check and !( $check & LEAVE_SRC() ); return $string; } +*bytes2str = \&decode; -sub from_to -{ - my ($string,$from,$to,$check) = @_; +sub from_to($$$;$) { + my ( $string, $from, $to, $check ) = @_; + return undef unless defined $string; + $check ||= 0; my $f = find_encoding($from); - croak("Unknown encoding '$from'") unless defined $f; + unless ( defined $f ) { + require Carp; + Carp::croak("Unknown encoding '$from'"); + } 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 length($_[0] = $string); + unless ( defined $t ) { + require Carp; + Carp::croak("Unknown encoding '$to'"); + } + my $uni = $f->decode($string); + $_[0] = $string = $t->encode( $uni, $check ); + return undef if ( $check && length($uni) ); + return defined( $_[0] ) ? length($string) : undef; } -sub encode_utf8 -{ +sub encode_utf8($) { my ($str) = @_; - utf8::encode($str); + utf8::encode($str); return $str; } -sub decode_utf8 -{ - my ($str) = @_; - return undef unless utf8::decode($str); - return $str; +sub decode_utf8($;$) { + my ( $str, $check ) = @_; + return $str if is_utf8($str); + if ($check) { + return decode( "utf8", $str, $check ); + } + else { + return decode( "utf8", $str ); + return $str; + } } -require Encode::Encoding; -require Encode::XS; -require Encode::Internal; -require Encode::Unicode; -require Encode::utf8; -require Encode::iso10646_1; -require Encode::ucs2_le; +predefine_encodings(1); + +# +# This is to restore %Encoding if really needed; +# + +sub predefine_encodings { + use Encode::Encoding; + no warnings 'redefine'; + my $use_xs = shift; + if ($ON_EBCDIC) { + + # was in Encode::UTF_EBCDIC + package Encode::UTF_EBCDIC; + push @Encode::UTF_EBCDIC::ISA, 'Encode::Encoding'; + *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 { + + package Encode::Internal; + push @Encode::Internal::ISA, 'Encode::Encoding'; + *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; + push @Encode::utf8::ISA, 'Encode::Encoding'; + + # + if ($use_xs) { + Encode::DEBUG and warn __PACKAGE__, " XS on"; + *decode = \&decode_xs; + *encode = \&encode_xs; + } + else { + Encode::DEBUG and warn __PACKAGE__, " XS off"; + *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; + }; + } + *cat_decode = sub { # ($obj, $dst, $src, $pos, $trm, $chk) + # currently ignores $chk + my ( $obj, undef, undef, $pos, $trm ) = @_; + my ( $rdst, $rsrc, $rpos ) = \@_[ 1, 2, 3 ]; + use bytes; + if ( ( my $npos = index( $$rsrc, $trm, $pos ) ) >= 0 ) { + $$rdst .= + substr( $$rsrc, $pos, $npos - $pos + length($trm) ); + $$rpos = $npos + length($trm); + return 1; + } + $$rdst .= substr( $$rsrc, $pos ); + $$rpos = length($$rsrc); + return ''; + }; + $Encode::Encoding{utf8} = + bless { Name => "utf8" } => "Encode::utf8"; + $Encode::Encoding{"utf-8-strict"} = + bless { Name => "utf-8-strict", strict_utf8 => 1 } => + "Encode::utf8"; + } +} 1; @@ -228,151 +325,161 @@ Encode - character encodings use Encode; -=head1 DESCRIPTION +=head2 Table of Contents -The C module provides the interfaces between Perl's strings -and the rest of the system. Perl strings are sequences of B. +Encode consists of a collection of modules whose 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: -To find more about character encodings, please consult -L . This document focuses on programming references. + Name Description + -------------------------------------------------------- + Encode::Alias Alias definitions 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 PERL ENCODING API - -=head2 Generic Encoding Interface +=head1 DESCRIPTION -=over 4 +The C module provides the interfaces between Perl's strings +and the rest of the system. Perl strings are sequences of +B. -=item * +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) 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). - $bytes = encode(ENCODING, $string[, CHECK]) +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 machine's representation of +numbers, pixels in an image - or just about anything. -Encodes string from Perl's internal form into I and returns -a sequence of octets. For CHECK see L. +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". -For example to convert (internally UTF-8 encoded) Unicode data -to octets: +=head2 TERMINOLOGY - $octets = encode("utf8", $unicode); +=over 2 =item * - $string = decode(ENCODING, $bytes[, CHECK]) - -Decode sequence of octets assumed to be in I into Perl's -internal form and returns the resulting string. For CHECK see -L. - -For example to convert ISO-8859-1 data to UTF-8: - - $utf8 = decode("latin1", $latin1); +I: a character in the range 0..(2**32-1) (or more). +(What Perl's strings are made of.) =item * - from_to($string, FROM_ENCODING, TO_ENCODING[, CHECK]) +I: a character in the range 0..255 +(A special case of a Perl character.) -Convert B the data between two encodings. How did the data -in $string originally get to be in FROM_ENCODING? Either using -encode() or through PerlIO: See L. For CHECK -see L. - -For example to convert ISO-8859-1 data to UTF-8: +=item * - from_to($data, "iso-8859-1", "utf-8"); +I: 8 bits of data, with ordinal values 0..255 +(Term for bytes passed to or from a non-Perl context, e.g. a disk file.) -and to convert it back: +=back - from_to($data, "utf-8", "iso-8859-1"); +=head1 PERL ENCODING API -Note that because the conversion happens in place, the data to be -converted cannot be a string constant, it must be a scalar variable. +=over 2 -=back +=item $octets = encode(ENCODING, $string [, CHECK]) -=head2 Handling Malformed Data +Encodes a string from Perl's internal form into I and returns +a sequence of octets. ENCODING can be either a canonical name or +an alias. For encoding names and aliases, see L. +For CHECK, see L. -If CHECK is not set, C 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. +For example, to convert a string from Perl's internal format to +iso-8859-1 (also known as Latin1), -It would desirable to have a way to indicate that transform should use -the encodings "replacement character" - no such mechanism is defined yet. + $octets = encode("iso-8859-1", $string); -It is also planned to allow I to be a code reference. +B: When you run C<$octets = encode("utf8", $string)>, then $octets +B $string. Though they both contain the same data, the UTF8 flag +for $octets is B off. When you encode anything, UTF8 flag of +the result is always off, even when it contains completely valid utf8 +string. See L below. -This is not yet implemented as there are design issues with what its -arguments should be and how it returns its results. +If the $string is C then C is returned. -=over 4 +=item $string = decode(ENCODING, $octets [, CHECK]) -=item Scheme 1 +Decodes a sequence of octets assumed to be in I into Perl's +internal form and returns the resulting string. As in encode(), +ENCODING can be either a canonical name or an alias. For encoding names +and aliases, see L. For CHECK, see +L. -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. +For example, to convert ISO-8859-1 data to a string in Perl's internal format: - sub fixup { - my $ch = substr($_[0],0,1,''); - return sprintf("\x{%02X}",ord($ch); - } + $string = decode("iso-8859-1", $octets); -This scheme is close to how underlying C code for Encode works, but gives -the fixup routine very little context. +B: When you run C<$string = decode("utf8", $octets)>, then $string +B $octets. Though they both contain the same data, +the UTF8 flag for $string is on unless $octets entirely consists of +ASCII data (or EBCDIC on EBCDIC machines). See L +below. -=item Scheme 2 +If the $string is C then C is returned. -Passed original string, and an index into it of the problem area, and -output string so far. Appends what it will to output string and -returns new index into original string. For example: +=item [$length =] from_to($octets, FROM_ENC, TO_ENC [, CHECK]) - sub fixup { - # my ($s,$i,$d) = @_; - my $ch = substr($_[0],$_[1],1); - $_[2] .= sprintf("\x{%02X}",ord($ch); - return $_[1]+1; - } +Converts B data between two encodings. The data in $octets +must be encoded as octets and not as characters in Perl's internal +format. For example, to convert ISO-8859-1 data to Microsoft's CP1250 +encoding: -This scheme gives maximal control to the fixup routine but is more -complicated to code, and may need internals of Encode to be tweaked to -keep original string intact. + from_to($octets, "iso-8859-1", "cp1250"); -=item Other Schemes +and to convert it back: -Hybrids of above. + from_to($octets, "cp1250", "iso-8859-1"); -Multiple return values rather than in-place modifications. +Note that because the conversion happens in place, the data to be +converted cannot be a string constant; it must be a scalar variable. -Index into the string could be pos($str) allowing s/\G...//. +from_to() returns the length of the converted string in octets on +success, I on error. -=back +B: The following operations look the same but are not quite so; -=head2 UTF-8 / utf8 + from_to($data, "iso-8859-1", "utf8"); #1 + $data = decode("iso-8859-1", $data); #2 -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). +Both #1 and #2 make $data consist of a completely valid UTF-8 string +but only #2 turns UTF8 flag on. #1 is equivalent to -=over 4 + $data = encode("utf8", decode("iso-8859-1", $data)); -=item * +See L below. - $bytes = encode_utf8($string); +=item $octets = encode_utf8($string); -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 +Equivalent to C<$octets = encode("utf8", $string);> The characters +that comprise $string are encoded in Perl's internal format and the +result is returned as a sequence of octets. All possible characters have a UTF-8 representation so this function cannot fail. -=item * - $string = decode_utf8($bytes [,CHECK]); +=item $string = decode_utf8($octets [, CHECK]); -The sequence of octets represented by $bytes is decoded from UTF-8 -into a sequence of logical characters. Not all sequences of octets -form valid UTF-8 encodings, so it is possible for this call to fail. -For CHECK see L. +equivalent to C<$string = decode("utf8", $octets [, CHECK])>. +The sequence of octets represented by +$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. =back @@ -387,147 +494,379 @@ ones that are not loaded yet, say @all_encodings = Encode->encodings(":all"); -Or you can give the name of specific module. +Or you can give the name of a specific module. + + @with_jp = Encode->encodings("Encode::JP"); - @with_jp = Encode->encodings("Encode/JP.pm"); +When "::" is not in the name, "Encode::" is assumed. -Note in this case you have to say "Encode/JP.pm instead of Encode::JP. + @ebcdic = Encode->encodings("EBCDIC"); -To find which encodings are suppoted by this package in details, +To find out in detail which encodings are supported by this package, see L. =head2 Defining Aliases +To add a new alias to a given encoding, use: + use Encode; use Encode::Alias; - define_alias( newName => ENCODING); + 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 + +But before you do so, make sure the alias is nonexistent with +C, which returns the canonical name thereof. +i.e. + + Encode::resolve_alias("latin1") eq "iso-8859-1" # true + Encode::resolve_alias("iso-8859-12") # false; nonexistent + Encode::resolve_alias($name) eq $name # true if $name is canonical + +resolve_alias() does not need C; it can be +exported via C. + +See L for details. + +=head1 Encoding via PerlIO + +If your perl supports I (which is the default), you can use a PerlIO layer to decode +and encode directly via a filehandle. The following two examples +are totally identical in their functionality. + + # via PerlIO + open my $in, "<:encoding(shiftjis)", $infile or die; + open my $out, ">:encoding(euc-jp)", $outfile or die; + while(<$in>){ print $out $_; } + + # via from_to + open my $in, "<", $infile or die; + open my $out, ">", $outfile or die; + while(<$in>){ + from_to($_, "shiftjis", "euc-jp", 1); + print $out $_; + } + +Unfortunately, it may be that encodings are PerlIO-savvy. You can check +if your encoding is supported by PerlIO by calling the C +method. + + Encode::perlio_ok("hz"); # False + find_encoding("euc-cn")->perlio_ok; # True where PerlIO is available + + use Encode qw(perlio_ok); # exported upon request + perlio_ok("euc-jp") + +Fortunately, all encodings that come with Encode core are PerlIO-savvy +except for hz and ISO-2022-kr. For gory details, see +L and L. + +=head1 Handling Malformed Data + +The optional I argument tells Encode what to do when it +encounters malformed data. Without CHECK, Encode::FB_DEFAULT ( == 0 ) +is assumed. + +As of version 2.12 Encode supports coderef values for CHECK. See below. + +=over 2 + +=item B Not all encoding support this feature + +Some encodings ignore I argument. For example, +L ignores I and it always croaks on error. + +=back + +Now here is the list of I values available + +=over 2 + +=item I = Encode::FB_DEFAULT ( == 0) + +If I is 0, (en|de)code will put a I in +place of a malformed character. When you encode, EsubcharE +will be used. When you decode the code point C<0xFFFD> is used. If +the data is supposed to be UTF-8, an optional lexical warning +(category utf8) is given. + +=item I = Encode::FB_CROAK ( == 1) + +If I is 1, methods will die on error immediately with an error +message. Therefore, when I is set to 1, you should trap the +error with eval{} unless you really want to let it die. + +=item I = Encode::FB_QUIET + +If I is set to Encode::FB_QUIET, (en|de)code will immediately +return the portion of the data that has been processed so far when an +error occurs. The data argument will be overwritten with everything +after that point (that is, the unprocessed part of data). This is +handy when you have to call decode repeatedly in the case where your +source data may contain partial multi-byte character sequences, +(i.e. you are reading with a fixed-width buffer). Here is a sample +code that does exactly this: + + my $buffer = ''; my $string = ''; + while(read $fh, $buffer, 256, length($buffer)){ + $string .= decode($encoding, $buffer, Encode::FB_QUIET); + # $buffer now contains the unprocessed partial character + } + +=item I = Encode::FB_WARN + +This is the same as above, except that it warns on error. Handy when +you are debugging the mode above. + +=item perlqq mode (I = Encode::FB_PERLQQ) + +=item HTML charref mode (I = Encode::FB_HTMLCREF) -Allows newName to be used as am alias for ENCODING. ENCODING may be -either the name of an encoding or and encoding object (as above). +=item XML charref mode (I = Encode::FB_XMLCREF) -See L on details. +For encodings that are implemented by Encode::XS, CHECK == +Encode::FB_PERLQQ turns (en|de)code into C fallback mode. + +When you decode, C<\xI> will be inserted for a malformed character, +where I is the hex representation of the octet that could not be +decoded to utf8. And when you encode, C<\x{I}> will be inserted, +where I is the Unicode ID of the character that cannot be found +in the character repertoire of the encoding. + +HTML/XML character reference modes are about the same, in place of +C<\x{I}>, HTML uses C<&#I;> where I is a decimal number and +XML uses C<&#xI;> where I is the hexadecimal number. + +In Encode 2.10 or later, C is also implied. + +=item The bitmask + +These modes are actually set via a bitmask. Here is how the FB_XX +constants are laid out. You can import the FB_XX constants via +C; you can import the generic bitmask +constants via C. + + FB_DEFAULT FB_CROAK FB_QUIET FB_WARN FB_PERLQQ + DIE_ON_ERR 0x0001 X + WARN_ON_ERR 0x0002 X + RETURN_ON_ERR 0x0004 X X + LEAVE_SRC 0x0008 X + PERLQQ 0x0100 X + HTMLCREF 0x0200 + XMLCREF 0x0400 + +=back + +=head2 coderef for CHECK + +As of Encode 2.12 CHECK can also be a code reference which takes the +ord value of unmapped caharacter as an argument and returns a string +that represents the fallback character. For instance, + + $ascii = encode("ascii", $utf8, sub{ sprintf "", shift }); + +Acts like FB_PERLQQ but EU+IE is used instead of +\x{I}. =head1 Defining Encodings - use Encode qw(define_alias); - define_encoding( $object, 'canonicalName' [,alias...]); +To define a new encoding, use: -Causes I to be associated with I<$object>. The object -should provide the interface described in L -below. If more than two arguments are provided then additional -arguments are taken as aliases for I<$object> as for C. + use Encode qw(define_encoding); + define_encoding($object, 'canonicalName' [, alias...]); -=head1 Encoding and IO +I will be associated with I<$object>. The object +should provide the interface described in L. +If more than two arguments are provided then additional +arguments are taken as aliases for I<$object>. -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 -C provides a "layer" (See L) which can transform -data as it is read or written. +See L for more details. -Here is how the blind poet would modernise the encoding: +=head1 The UTF8 flag - 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); +Before the introduction of Unicode support in perl, The C operator +just compared the strings represented by two scalars. Beginning with +perl 5.8, C compares two strings with simultaneous consideration of +I. To explain why we made it so, I will quote page 402 of +C + +=over 2 + +=item Goal #1: + +Old byte-oriented programs should not spontaneously break on the old +byte-oriented data they used to work on. + +=item Goal #2: + +Old byte-oriented programs should magically start working on the new +character-oriented data when appropriate. -In addition the new IO system can also be configured to read/write -UTF-8 encoded characters (as noted above this is efficient): +=item Goal #3: - open(my $fh,'>:utf8','anything'); - print $fh "Any \x{0021} string \N{SMILEY FACE}\n"; +Programs should run just as fast in the new character-oriented mode +as in the old byte-oriented mode. -Either of the above forms of "layer" specifications can be made the default -for a lexical scope with the C pragma. See L. +=item Goal #4: -Once a handle is open is layers can be altered using C. +Perl should remain one language, rather than forking into a +byte-oriented Perl and a character-oriented Perl. -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 and will C 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. +=back + +Back when C was written, not even Perl 5.6.0 +was born and many features documented in the book remained +unimplemented for a long time. Perl 5.8 corrected this and the introduction +of the UTF8 flag is one of them. You can think of this perl notion as of a +byte-oriented mode (UTF8 flag off) and a character-oriented mode (UTF8 +flag on). -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, C, ...). +Here is how Encode takes care of the UTF8 flag. -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): +=over 2 - open(F, "<:encoding(iso-8859-1)", "data.txt") or die $!; - open(G, ">:utf8", "data.utf") or die $!; - while () { print G } +=item * - # Could also do "print G " but that would pull - # the whole file into memory just to write it out again. +When you encode, the resulting UTF8 flag is always off. + +=item * -More examples: +When you decode, the resulting UTF8 flag is on unless you can +unambiguously represent data. Here is the definition of +dis-ambiguity. - open(my $f, "<:encoding(cp1252)") - open(my $g, ">:encoding(iso-8859-2)") - open(my $h, ">:encoding(latin9)") # iso-8859-15 +After C<$utf8 = decode('foo', $octet);>, -See L for more information. + When $octet is... The UTF8 flag in $utf8 is + --------------------------------------------- + In ASCII only (or EBCDIC only) OFF + In ISO-8859-1 ON + In any other Encoding ON + --------------------------------------------- -See also L for how to change the default encoding of the -data in your script. +As you see, there is one exception, In ASCII. That way you can assume +Goal #1. And with Encode Goal #2 is assumed but you still have to be +careful in such cases mentioned in B paragraphs. -=head1 Messing with Perl's Internals +This UTF8 flag is not visible in perl scripts, exactly for the same +reason you cannot (or you I) see if a scalar contains a +string, integer, or floating point number. But you can still peek +and poke these if you will. See the section below. + +=back + +=head2 Messing with Perl's Internals The following API uses parts of Perl's internals in the current -implementation. As such they are efficient, but may change. +implementation. As such, they are efficient but may change. -=over 4 +=over 2 -=item * is_utf8(STRING [, CHECK]) +=item is_utf8(STRING [, CHECK]) -[INTERNAL] Test whether the UTF-8 flag is turned on in the STRING. +[INTERNAL] Tests whether the UTF8 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. -=item * +As of perl 5.8.1, L also has utf8::is_utf8(). - _utf8_on(STRING) +=item _utf8_on(STRING) -[INTERNAL] Turn on the UTF-8 flag in STRING. The data in STRING is +[INTERNAL] Turns on the UTF8 flag in STRING. The data in STRING is B checked for being well-formed UTF-8. Do not use unless you B that the STRING is well-formed UTF-8. Returns the previous -state of the UTF-8 flag (so please don't test the return value as -I success or failure), or C if STRING is not a string. +state of the UTF8 flag (so please don't treat the return value as +indicating success or failure), or C 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 -return value as I success or failure), or C if STRING is +[INTERNAL] Turns off the UTF8 flag in STRING. Do not use frivolously. +Returns the previous state of the UTF8 flag (so please don't treat the +return value as indicating success or failure), or C if STRING is not a string. =back +=head1 UTF-8 vs. utf8 vs. UTF8 + + ....We now view strings not as sequences of bytes, but as sequences + of numbers in the range 0 .. 2**32-1 (or in the case of 64-bit + computers, 0 .. 2**64-1) -- Programming Perl, 3rd ed. + +That has been the perl's notion of UTF-8 but official UTF-8 is more +strict; Its ranges is much narrower (0 .. 10FFFF), some sequences are +not allowed (i.e. Those used in the surrogate pair, 0xFFFE, et al). + +Now that is overruled by Larry Wall himself. + + From: Larry Wall + Date: December 04, 2004 11:51:58 JST + To: perl-unicode@perl.org + Subject: Re: Make Encode.pm support the real UTF-8 + Message-Id: <20041204025158.GA28754@wall.org> + + On Fri, Dec 03, 2004 at 10:12:12PM +0000, Tim Bunce wrote: + : I've no problem with 'utf8' being perl's unrestricted uft8 encoding, + : but "UTF-8" is the name of the standard and should give the + : corresponding behaviour. + + For what it's worth, that's how I've always kept them straight in my + head. + + Also for what it's worth, Perl 6 will mostly default to strict but + make it easy to switch back to lax. + + Larry + +Do you copy? As of Perl 5.8.7, B means strict, official UTF-8 +while B means liberal, lax, version thereof. And Encode version +2.10 or later thus groks the difference between C and C"utf8". + + encode("utf8", "\x{FFFF_FFFF}", 1); # okay + encode("UTF-8", "\x{FFFF_FFFF}", 1); # croaks + +C in Encode is actually a canonical name for C. +Yes, the hyphen between "UTF" and "8" is important. Without it Encode +goes "liberal" + + find_encoding("UTF-8")->name # is 'utf-8-strict' + find_encoding("utf-8")->name # ditto. names are case insensitive + find_encoding("utf_8")->name # ditto. "_" are treated as "-" + find_encoding("UTF8")->name # is 'utf8'. + +The UTF8 flag is internally called UTF8, without a hyphen. It indicates +whether a string is internally encoded as utf8, also without a hypen. + =head1 SEE ALSO -L, L, L, -L, +L, L, -L, -L, -L, -L, +L, +L, +L, +L, the Perl Unicode Mailing List Eperl-unicode@perl.orgE +=head1 MAINTAINER + +This project was originated by Nick Ing-Simmons and later maintained +by Dan Kogai Edankogai@dan.co.jpE. See AUTHORS for a full +list of people involved. For any questions, use +Eperl-unicode@perl.orgE so we can all share. + +While Dan Kogai retains the copyright as a maintainer, the credit +should go to all those involoved. See AUTHORS for those submitted +codes. + +=head1 COPYRIGHT + +Copyright 2002-2006 Dan Kogai Edankogai@dan.co.jpE + +This library is free software; you can redistribute it and/or modify +it under the same terms as Perl itself. + =cut