3 our $VERSION = do { my @r = (q$Revision: 1.52 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
6 XSLoader::load 'Encode';
9 our @ISA = qw(Exporter);
11 # Public, encouraged API is exported by default
14 decode decode_utf8 encode encode_utf8
15 encodings find_encoding
18 our @FB_FLAGS = qw(DIE_ON_ERR WARN_ON_ERR RETURN_ON_ERR LEAVE_SRC PERLQQ);
19 our @FB_CONSTS = qw(FB_DEFAULT FB_QUIET FB_WARN FB_PERLQQ FB_CROAK);
24 _utf8_off _utf8_on define_encoding from_to is_16bit is_8bit
25 is_utf8 perlio_ok resolve_alias utf8_downgrade utf8_upgrade
27 @FB_FLAGS, @FB_CONSTS,
32 all => [ @EXPORT, @EXPORT_OK ],
33 fallbacks => [ @FB_CONSTS ],
34 fallback_all => [ @FB_CONSTS, @FB_FLAGS ],
37 # Documentation moved after __END__ for speed - NI-S
41 our $ON_EBCDIC = (ord("A") == 193);
45 # Make a %Encoding package variable to allow a certain amount of cheating
48 require Encode::Config;
49 eval { require Encode::ConfigLocal };
54 my @modules = (@_ and $_[0] eq ":all") ? values %ExtModule : @_;
55 for my $mod (@modules){
56 $mod =~ s,::,/,g or $mod = "Encode/$mod";
58 $DEBUG and warn "about to require $mod;";
59 eval { require $mod; };
61 my %modules = map {$_ => 1} @modules;
63 sort { lc $a cmp lc $b }
64 grep {!/^(?:Internal|Unicode)$/o} keys %Encoding;
68 exists $INC{"PerlIO/encoding.pm"} or return 0;
69 my $stash = ref($_[0]);
70 $stash ||= ref(find_encoding($_[0]));
71 return ($stash eq "Encode::XS" || $stash eq "Encode::Unicode");
78 $Encoding{$name} = $obj;
80 define_alias($lc => $obj) unless $lc eq $name;
84 define_alias($alias,$obj);
91 my ($class,$name,$skip_external) = @_;
93 if (ref($name) && $name->can('new_sequence'))
98 if (exists $Encoding{$name})
100 return $Encoding{$name};
102 if (exists $Encoding{$lc})
104 return $Encoding{$lc};
107 my $oc = $class->find_alias($name);
108 return $oc if defined $oc;
110 $oc = $class->find_alias($lc) if $lc ne $name;
111 return $oc if defined $oc;
113 unless ($skip_external)
115 if (my $mod = $ExtModule{$name} || $ExtModule{$lc}){
116 $mod =~ s,::,/,g ; $mod .= '.pm';
117 eval{ require $mod; };
118 return $Encoding{$name} if exists $Encoding{$name};
126 my ($name,$skip_external) = @_;
127 return __PACKAGE__->getEncoding($name,$skip_external);
131 my $obj = find_encoding(shift);
132 defined $obj and return $obj->name;
138 my ($name,$string,$check) = @_;
140 my $enc = find_encoding($name);
141 croak("Unknown encoding '$name'") unless defined $enc;
142 my $octets = $enc->encode($string,$check);
143 return undef if ($check && length($string));
149 my ($name,$octets,$check) = @_;
151 my $enc = find_encoding($name);
152 croak("Unknown encoding '$name'") unless defined $enc;
153 my $string = $enc->decode($octets,$check);
154 $_[1] = $octets if $check;
160 my ($string,$from,$to,$check) = @_;
162 my $f = find_encoding($from);
163 croak("Unknown encoding '$from'") unless defined $f;
164 my $t = find_encoding($to);
165 croak("Unknown encoding '$to'") unless defined $t;
166 my $uni = $f->decode($string,$check);
167 return undef if ($check && length($string));
168 $string = $t->encode($uni,$check);
169 return undef if ($check && length($uni));
170 return defined($_[0] = $string) ? length($string) : undef ;
183 return undef unless utf8::decode($str);
187 predefine_encodings();
190 # This is to restore %Encoding if really needed;
192 sub predefine_encodings{
194 # was in Encode::UTF_EBCDIC
195 package Encode::UTF_EBCDIC;
196 *name = sub{ shift->{'Name'} };
197 *new_sequence = sub{ return $_[0] };
199 my ($obj,$str,$chk) = @_;
201 for (my $i = 0; $i < length($str); $i++) {
203 chr(utf8::unicode_to_native(ord(substr($str,$i,1))));
209 my ($obj,$str,$chk) = @_;
211 for (my $i = 0; $i < length($str); $i++) {
213 chr(utf8::native_to_unicode(ord(substr($str,$i,1))));
218 $Encode::Encoding{Unicode} =
219 bless {Name => "UTF_EBCDIC"} => "Encode::UTF_EBCDIC";
221 # was in Encode::UTF_EBCDIC
222 package Encode::Internal;
223 *name = sub{ shift->{'Name'} };
224 *new_sequence = sub{ return $_[0] };
226 my ($obj,$str,$chk) = @_;
232 $Encode::Encoding{Unicode} =
233 bless {Name => "Internal"} => "Encode::Internal";
237 # was in Encode::utf8
238 package Encode::utf8;
239 *name = sub{ shift->{'Name'} };
240 *new_sequence = sub{ return $_[0] };
242 my ($obj,$octets,$chk) = @_;
243 my $str = Encode::decode_utf8($octets);
251 my ($obj,$string,$chk) = @_;
252 my $octets = Encode::encode_utf8($string);
256 $Encode::Encoding{utf8} =
257 bless {Name => "utf8"} => "Encode::utf8";
261 require Encode::Encoding;
262 @Encode::XS::ISA = qw(Encode::Encoding);
264 # This is very dodgy - PerlIO::encoding does "use Encode" and _BEFORE_ it gets a
265 # chance to set its VERSION we potentially delete it from %INC so it will be re-loaded
268 require PerlIO::encoding;
269 unless (PerlIO::encoding->VERSION >= 0.02){
270 delete $INC{"PerlIO/encoding.pm"};
274 @Encode::XS::ISA = qw(Encode::Encoding);
282 Encode - character encodings
289 =head2 Table of Contents
291 Encode consists of a collection of modules which details are too big
292 to fit in one document. This POD itself explains the top-level APIs
293 and general topics at a glance. For other topics and more details,
297 --------------------------------------------------------
298 Encode::Alias Alias definitions to encodings
299 Encode::Encoding Encode Implementation Base Class
300 Encode::Supported List of Supported Encodings
301 Encode::CN Simplified Chinese Encodings
302 Encode::JP Japanese Encodings
303 Encode::KR Korean Encodings
304 Encode::TW Traditional Chinese Encodings
305 --------------------------------------------------------
309 The C<Encode> module provides the interfaces between Perl's strings
310 and the rest of the system. Perl strings are sequences of
313 The repertoire of characters that Perl can represent is at least that
314 defined by the Unicode Consortium. On most platforms the ordinal
315 values of the characters (as returned by C<ord(ch)>) is the "Unicode
316 codepoint" for the character (the exceptions are those platforms where
317 the legacy encoding is some variant of EBCDIC rather than a super-set
318 of ASCII - see L<perlebcdic>).
320 Traditionally computer data has been moved around in 8-bit chunks
321 often called "bytes". These chunks are also known as "octets" in
322 networking standards. Perl is widely used to manipulate data of many
323 types - not only strings of characters representing human or computer
324 languages but also "binary" data being the machines representation of
325 numbers, pixels in an image - or just about anything.
327 When Perl is processing "binary data" the programmer wants Perl to
328 process "sequences of bytes". This is not a problem for Perl - as a
329 byte has 256 possible values it easily fits in Perl's much larger
338 I<character>: a character in the range 0..(2**32-1) (or more).
339 (What Perl's strings are made of.)
343 I<byte>: a character in the range 0..255
344 (A special case of a Perl character.)
348 I<octet>: 8 bits of data, with ordinal values 0..255
349 (Term for bytes passed to or from a non-Perl context, e.g. disk file.)
353 The marker [INTERNAL] marks Internal Implementation Details, in
354 general meant only for those who think they know what they are doing,
355 and such details may change in future releases.
357 =head1 PERL ENCODING API
361 =item $octets = encode(ENCODING, $string[, CHECK])
363 Encodes string from Perl's internal form into I<ENCODING> and returns
364 a sequence of octets. ENCODING can be either a canonical name or
365 alias. For encoding names and aliases, see L</"Defining Aliases">.
366 For CHECK see L</"Handling Malformed Data">.
368 For example to convert (internally UTF-8 encoded) Unicode string to
369 iso-8859-1 (also known as Latin1),
371 $octets = encode("iso-8859-1", $unicode);
373 =item $string = decode(ENCODING, $octets[, CHECK])
375 Decode sequence of octets assumed to be in I<ENCODING> into Perl's
376 internal form and returns the resulting string. as in encode(),
377 ENCODING can be either a canonical name or alias. For encoding names
378 and aliases, see L</"Defining Aliases">. For CHECK see
379 L</"Handling Malformed Data">.
381 For example to convert ISO-8859-1 data to UTF-8:
383 $utf8 = decode("iso-8859-1", $latin1);
385 =item [$length =] from_to($string, FROM_ENCODING, TO_ENCODING [,CHECK])
387 Convert B<in-place> the data between two encodings.
388 For example to convert ISO-8859-1 data to UTF-8:
390 from_to($data, "iso-8859-1", "utf-8");
392 and to convert it back:
394 from_to($data, "utf-8", "iso-8859-1");
396 Note that because the conversion happens in place, the data to be
397 converted cannot be a string constant, it must be a scalar variable.
399 from_to() return the length of the converted string on success, undef
406 The Unicode consortium defines the UTF-8 standard as a way of encoding
407 the entire Unicode repertoire as sequences of octets. This encoding is
408 expected to become very widespread. Perl can use this form internally
409 to represent strings, so conversions to and from this form are
410 particularly efficient (as octets in memory do not have to change,
411 just the meta-data that tells Perl how to treat them).
415 =item $octets = encode_utf8($string);
417 The characters that comprise string are encoded in Perl's superset of UTF-8
418 and the resulting octets returned as a sequence of bytes. All possible
419 characters have a UTF-8 representation so this function cannot fail.
421 =item $string = decode_utf8($octets [, CHECK]);
423 The sequence of octets represented by $octets is decoded from UTF-8
424 into a sequence of logical characters. Not all sequences of octets
425 form valid UTF-8 encodings, so it is possible for this call to fail.
426 For CHECK see L</"Handling Malformed Data">.
430 =head2 Listing available encodings
433 @list = Encode->encodings();
435 Returns a list of the canonical names of the available encodings that
436 are loaded. To get a list of all available encodings including the
437 ones that are not loaded yet, say
439 @all_encodings = Encode->encodings(":all");
441 Or you can give the name of specific module.
443 @with_jp = Encode->encodings("Encode::JP");
445 When "::" is not in the name, "Encode::" is assumed.
447 @ebcdic = Encode->encodings("EBCDIC");
449 To find which encodings are supported by this package in details,
450 see L<Encode::Supported>.
452 =head2 Defining Aliases
454 To add new alias to a given encoding, Use;
458 define_alias(newName => ENCODING);
460 After that, newName can be used as an alias for ENCODING.
461 ENCODING may be either the name of an encoding or an
464 But before you do so, make sure the alias is nonexistent with
465 C<resolve_alias()>, which returns the canonical name thereof.
468 Encode::resolve_alias("latin1") eq "iso-8859-1" # true
469 Encode::resolve_alias("iso-8859-12") # false; nonexistent
470 Encode::resolve_alias($name) eq $name # true if $name is canonical
472 This resolve_alias() does not need C<use Encode::Alias> and is
473 exported via C<use encode qw(resolve_alias)>.
475 See L<Encode::Alias> on details.
477 =head1 Encoding via PerlIO
479 If your perl supports I<PerlIO>, you can use PerlIO layer to directly
480 decode and encode via filehandle. The following two examples are
481 totally identical by functionality.
484 open my $in, "<:encoding(shiftjis)", $infile or die;
485 open my $out, ">:encoding(euc-jp)", $outfile or die;
489 open my $in, $infile or die;
490 open my $out, $outfile or die;
492 from_to($_, "shiftjis", "euc", 1);
495 Unfortunately, not all encodings are PerlIO-savvy. You can check if
496 your encoding is supported by PerlIO by C<perlio_ok> method.
498 Encode::perlio_ok("iso-20220jp"); # false
499 find_encoding("iso-2022-jp")->perlio_ok; # false
500 use Encode qw(perlio_ok); # exported upon request
501 perlio_ok("euc-jp") # true if PerlIO is enabled
503 For gory details, see L<Encode::PerlIO>;
505 =head1 Handling Malformed Data
509 THE I<CHECK> argument is used as follows. When you omit it, it is
510 identical to I<CHECK> = 0.
512 =item I<CHECK> = Encode::FB_DEFAULT ( == 0)
514 If I<CHECK> is 0, (en|de)code will put I<substitution character> in
515 place of the malformed character. for UCM-based encodings,
516 E<lt>subcharE<gt> will be used. For Unicode, \xFFFD is used. If the
517 data is supposed to be UTF-8, an optional lexical warning (category
520 =item I<CHECK> = Encode::DIE_ON_ERROR (== 1)
522 If I<CHECK> is 1, methods will die immediately with an error
523 message. so when I<CHECK> is set, you should trap the fatal error
524 with eval{} unless you really want to let it die on error.
526 =item I<CHECK> = Encode::FB_QUIET
528 If I<CHECK> is set to Encode::FB_QUIET, (en|de)code will immediately
529 return processed part on error, with data passed via argument
530 overwritten with unprocessed part. This is handy when have to
531 repeatedly call because the source data is chopped in the middle for
532 some reasons, such as fixed-width buffer. Here is a sample code that
536 while(defined(read $fh, $buffer, 256)){
537 # buffer may end in partial character so we append
539 $utf8 .= decode($encoding, $data, ENCODE::FB_QUIET);
540 # $data now contains unprocessed partial character
543 =item I<CHECK> = Encode::FB_WARN
545 This is the same as above, except it warns on error. Handy when you
546 are debugging the mode above.
548 =item perlqq mode (I<CHECK> = Encode::FB_PERLQQ)
550 For encodings that are implemented by Encode::XS, CHECK ==
551 Encode::FB_PERLQQ turns (en|de)code into C<perlqq> fallback mode.
553 When you decode, '\xI<XX>' will be placed where I<XX> is the hex
554 representation of the octet that could not be decoded to utf8. And
555 when you encode, '\x{I<xxxx>}' will be placed where I<xxxx> is the
556 Unicode ID of the character that cannot be found in the character
557 repertoire of the encoding.
561 These modes are actually set via bitmask. here is how FB_XX are laid
562 out. for FB_XX you can import via C<use Encode qw(:fallbacks)> for
563 generic bitmask constants, you can import via
564 C<use Encode qw(:fallback_all)>.
566 FB_DEFAULT FB_CROAK FB_QUIET FB_WARN FB_PERLQQ
569 RETURN_ON_ERR 0x0004 X X
573 =head2 Unemplemented fallback schemes
575 In future you will be able to use a code reference to a callback
576 function for the value of I<CHECK> but its API is still undecided.
578 =head1 Defining Encodings
580 To define a new encoding, use:
582 use Encode qw(define_alias);
583 define_encoding($object, 'canonicalName' [, alias...]);
585 I<canonicalName> will be associated with I<$object>. The object
586 should provide the interface described in L<Encode::Encoding>
587 If more than two arguments are provided then additional
588 arguments are taken as aliases for I<$object> as for C<define_alias>.
590 See L<Encode::Encoding> for more details.
592 =head1 Messing with Perl's Internals
594 The following API uses parts of Perl's internals in the current
595 implementation. As such they are efficient, but may change.
599 =item is_utf8(STRING [, CHECK])
601 [INTERNAL] Test whether the UTF-8 flag is turned on in the STRING.
602 If CHECK is true, also checks the data in STRING for being well-formed
603 UTF-8. Returns true if successful, false otherwise.
605 =item _utf8_on(STRING)
607 [INTERNAL] Turn on the UTF-8 flag in STRING. The data in STRING is
608 B<not> checked for being well-formed UTF-8. Do not use unless you
609 B<know> that the STRING is well-formed UTF-8. Returns the previous
610 state of the UTF-8 flag (so please don't test the return value as
611 I<not> success or failure), or C<undef> if STRING is not a string.
613 =item _utf8_off(STRING)
615 [INTERNAL] Turn off the UTF-8 flag in STRING. Do not use frivolously.
616 Returns the previous state of the UTF-8 flag (so please don't test the
617 return value as I<not> success or failure), or C<undef> if STRING is
625 L<Encode::Supported>,
632 the Perl Unicode Mailing List E<lt>perl-unicode@perl.orgE<gt>
636 This project was originated by Nick Ing-Simmons and later maintained
637 by Dan Kogai E<lt>dankogai@dan.co.jpE<gt>. See AUTHORS for full list
638 of people involved. For any questions, use
639 E<lt>perl-unicode@perl.orgE<gt> so others can share.