3 our $VERSION = do { my @r = (q$Revision: 1.50 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
9 our @ISA = qw(Exporter DynaLoader);
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 ],
40 # Documentation moved after __END__ for speed - NI-S
44 our $ON_EBCDIC = (ord("A") == 193);
48 # Make a %Encoding package variable to allow a certain amount of cheating
51 require Encode::Config;
52 eval { require Encode::ConfigLocal };
57 my @modules = (@_ and $_[0] eq ":all") ? values %ExtModule : @_;
58 for my $mod (@modules){
59 $mod =~ s,::,/,g or $mod = "Encode/$mod";
61 $DEBUG and warn "about to require $mod;";
62 eval { require $mod; };
64 my %modules = map {$_ => 1} @modules;
66 sort { lc $a cmp lc $b }
67 grep {!/^(?:Internal|Unicode)$/o} keys %Encoding;
71 exists $INC{"PerlIO/encoding.pm"} or return 0;
72 my $stash = ref($_[0]);
73 $stash ||= ref(find_encoding($_[0]));
74 return ($stash eq "Encode::XS" || $stash eq "Encode::Unicode");
81 $Encoding{$name} = $obj;
83 define_alias($lc => $obj) unless $lc eq $name;
87 define_alias($alias,$obj);
94 my ($class,$name,$skip_external) = @_;
96 if (ref($name) && $name->can('new_sequence'))
101 if (exists $Encoding{$name})
103 return $Encoding{$name};
105 if (exists $Encoding{$lc})
107 return $Encoding{$lc};
110 my $oc = $class->find_alias($name);
111 return $oc if defined $oc;
113 $oc = $class->find_alias($lc) if $lc ne $name;
114 return $oc if defined $oc;
116 unless ($skip_external)
118 if (my $mod = $ExtModule{$name} || $ExtModule{$lc}){
119 $mod =~ s,::,/,g ; $mod .= '.pm';
120 eval{ require $mod; };
121 return $Encoding{$name} if exists $Encoding{$name};
129 my ($name,$skip_external) = @_;
130 return __PACKAGE__->getEncoding($name,$skip_external);
134 my $obj = find_encoding(shift);
135 defined $obj and return $obj->name;
141 my ($name,$string,$check) = @_;
143 my $enc = find_encoding($name);
144 croak("Unknown encoding '$name'") unless defined $enc;
145 my $octets = $enc->encode($string,$check);
146 return undef if ($check && length($string));
152 my ($name,$octets,$check) = @_;
154 my $enc = find_encoding($name);
155 croak("Unknown encoding '$name'") unless defined $enc;
156 my $string = $enc->decode($octets,$check);
157 $_[1] = $octets if $check;
163 my ($string,$from,$to,$check) = @_;
165 my $f = find_encoding($from);
166 croak("Unknown encoding '$from'") unless defined $f;
167 my $t = find_encoding($to);
168 croak("Unknown encoding '$to'") unless defined $t;
169 my $uni = $f->decode($string,$check);
170 return undef if ($check && length($string));
171 $string = $t->encode($uni,$check);
172 return undef if ($check && length($uni));
173 return defined($_[0] = $string) ? length($string) : undef ;
186 return undef unless utf8::decode($str);
190 predefine_encodings();
193 # This is to restore %Encoding if really needed;
195 sub predefine_encodings{
197 # was in Encode::UTF_EBCDIC
198 package Encode::UTF_EBCDIC;
199 *name = sub{ shift->{'Name'} };
200 *new_sequence = sub{ return $_[0] };
202 my ($obj,$str,$chk) = @_;
204 for (my $i = 0; $i < length($str); $i++) {
206 chr(utf8::unicode_to_native(ord(substr($str,$i,1))));
212 my ($obj,$str,$chk) = @_;
214 for (my $i = 0; $i < length($str); $i++) {
216 chr(utf8::native_to_unicode(ord(substr($str,$i,1))));
221 $Encode::Encoding{Unicode} =
222 bless {Name => "UTF_EBCDIC"} => "Encode::UTF_EBCDIC";
224 # was in Encode::UTF_EBCDIC
225 package Encode::Internal;
226 *name = sub{ shift->{'Name'} };
227 *new_sequence = sub{ return $_[0] };
229 my ($obj,$str,$chk) = @_;
235 $Encode::Encoding{Unicode} =
236 bless {Name => "Internal"} => "Encode::Internal";
240 # was in Encode::utf8
241 package Encode::utf8;
242 *name = sub{ shift->{'Name'} };
243 *new_sequence = sub{ return $_[0] };
245 my ($obj,$octets,$chk) = @_;
246 my $str = Encode::decode_utf8($octets);
254 my ($obj,$string,$chk) = @_;
255 my $octets = Encode::encode_utf8($string);
259 $Encode::Encoding{utf8} =
260 bless {Name => "utf8"} => "Encode::utf8";
264 require Encode::Encoding;
266 eval qq{ use PerlIO::encoding 0.02 };
275 Encode - character encodings
282 =head2 Table of Contents
284 Encode consists of a collection of modules which details are too big
285 to fit in one document. This POD itself explains the top-level APIs
286 and general topics at a glance. For other topics and more details,
290 --------------------------------------------------------
291 Encode::Alias Alias defintions to encodings
292 Encode::Encoding Encode Implementation Base Class
293 Encode::Supported List of Supported Encodings
294 Encode::CN Simplified Chinese Encodings
295 Encode::JP Japanese Encodings
296 Encode::KR Korean Encodings
297 Encode::TW Traditional Chinese Encodings
298 --------------------------------------------------------
302 The C<Encode> module provides the interfaces between Perl's strings
303 and the rest of the system. Perl strings are sequences of
306 The repertoire of characters that Perl can represent is at least that
307 defined by the Unicode Consortium. On most platforms the ordinal
308 values of the characters (as returned by C<ord(ch)>) is the "Unicode
309 codepoint" for the character (the exceptions are those platforms where
310 the legacy encoding is some variant of EBCDIC rather than a super-set
311 of ASCII - see L<perlebcdic>).
313 Traditionally computer data has been moved around in 8-bit chunks
314 often called "bytes". These chunks are also known as "octets" in
315 networking standards. Perl is widely used to manipulate data of many
316 types - not only strings of characters representing human or computer
317 languages but also "binary" data being the machines representation of
318 numbers, pixels in an image - or just about anything.
320 When Perl is processing "binary data" the programmer wants Perl to
321 process "sequences of bytes". This is not a problem for Perl - as a
322 byte has 256 possible values it easily fits in Perl's much larger
331 I<character>: a character in the range 0..(2**32-1) (or more).
332 (What Perl's strings are made of.)
336 I<byte>: a character in the range 0..255
337 (A special case of a Perl character.)
341 I<octet>: 8 bits of data, with ordinal values 0..255
342 (Term for bytes passed to or from a non-Perl context, e.g. disk file.)
346 The marker [INTERNAL] marks Internal Implementation Details, in
347 general meant only for those who think they know what they are doing,
348 and such details may change in future releases.
350 =head1 PERL ENCODING API
354 =item $octets = encode(ENCODING, $string[, CHECK])
356 Encodes string from Perl's internal form into I<ENCODING> and returns
357 a sequence of octets. ENCODING can be either a canonical name or
358 alias. For encoding names and aliases, see L</"Defining Aliases">.
359 For CHECK see L</"Handling Malformed Data">.
361 For example to convert (internally UTF-8 encoded) Unicode string to
362 iso-8859-1 (also known as Latin1),
364 $octets = encode("iso-8859-1", $unicode);
366 =item $string = decode(ENCODING, $octets[, CHECK])
368 Decode sequence of octets assumed to be in I<ENCODING> into Perl's
369 internal form and returns the resulting string. as in encode(),
370 ENCODING can be either a canonical name or alias. For encoding names
371 and aliases, see L</"Defining Aliases">. For CHECK see
372 L</"Handling Malformed Data">.
374 For example to convert ISO-8859-1 data to UTF-8:
376 $utf8 = decode("iso-8859-1", $latin1);
378 =item [$length =] from_to($string, FROM_ENCODING, TO_ENCODING [,CHECK])
380 Convert B<in-place> the data between two encodings.
381 For example to convert ISO-8859-1 data to UTF-8:
383 from_to($data, "iso-8859-1", "utf-8");
385 and to convert it back:
387 from_to($data, "utf-8", "iso-8859-1");
389 Note that because the conversion happens in place, the data to be
390 converted cannot be a string constant, it must be a scalar variable.
392 from_to() return the length of the converted string on success, undef
399 The Unicode consortium defines the UTF-8 standard as a way of encoding
400 the entire Unicode repertoire as sequences of octets. This encoding is
401 expected to become very widespread. Perl can use this form internally
402 to represent strings, so conversions to and from this form are
403 particularly efficient (as octets in memory do not have to change,
404 just the meta-data that tells Perl how to treat them).
408 =item $octets = encode_utf8($string);
410 The characters that comprise string are encoded in Perl's superset of UTF-8
411 and the resulting octets returned as a sequence of bytes. All possible
412 characters have a UTF-8 representation so this function cannot fail.
414 =item $string = decode_utf8($octets [, CHECK]);
416 The sequence of octets represented by $octets is decoded from UTF-8
417 into a sequence of logical characters. Not all sequences of octets
418 form valid UTF-8 encodings, so it is possible for this call to fail.
419 For CHECK see L</"Handling Malformed Data">.
423 =head2 Listing available encodings
426 @list = Encode->encodings();
428 Returns a list of the canonical names of the available encodings that
429 are loaded. To get a list of all available encodings including the
430 ones that are not loaded yet, say
432 @all_encodings = Encode->encodings(":all");
434 Or you can give the name of specific module.
436 @with_jp = Encode->encodings("Encode::JP");
438 When "::" is not in the name, "Encode::" is assumed.
440 @ebcdic = Encode->encodings("EBCDIC");
442 To find which encodings are supported by this package in details,
443 see L<Encode::Supported>.
445 =head2 Defining Aliases
447 To add new alias to a given encoding, Use;
451 define_alias(newName => ENCODING);
453 After that, newName can be used as an alias for ENCODING.
454 ENCODING may be either the name of an encoding or an
457 But before you do so, make sure the alias is nonexistent with
458 C<resolve_alias()>, which returns the canonical name thereof.
461 Encode::resolve_alias("latin1") eq "iso-8859-1" # true
462 Encode::resolve_alias("iso-8859-12") # false; nonexistent
463 Encode::resolve_alias($name) eq $name # true if $name is canonical
465 This resolve_alias() does not need C<use Encode::Alias> and is
466 exported via C<use encode qw(resolve_alias)>.
468 See L<Encode::Alias> on details.
470 =head1 Encoding via PerlIO
472 If your perl supports I<PerlIO>, you can use PerlIO layer to directly
473 decode and encode via filehandle. The following two examples are
474 totally identical by functionality.
477 open my $in, "<:encoding(shiftjis)", $infile or die;
478 open my $out, ">:encoding(euc-jp)", $outfile or die;
482 open my $in, $infile or die;
483 open my $out, $outfile or die;
485 from_to($_, "shiftjis", "euc", 1);
488 Unfortunately, not all encodings are PerlIO-savvy. You can check if
489 your encoding is supported by PerlIO by C<perlio_ok> method.
491 Encode::perlio_ok("iso-20220jp"); # false
492 find_encoding("iso-2022-jp")->perlio_ok; # false
493 use Encode qw(perlio_ok); # exported upon request
494 perlio_ok("euc-jp") # true if PerlIO is enabled
496 For gory details, see L<Encode::PerlIO>;
498 =head1 Handling Malformed Data
502 THE I<CHECK> argument is used as follows. When you omit it, it is
503 identical to I<CHECK> = 0.
505 =item I<CHECK> = Encode::FB_DEFAULT ( == 0)
507 If I<CHECK> is 0, (en|de)code will put I<substitution character> in
508 place of the malformed character. for UCM-based encodings,
509 E<lt>subcharE<gt> will be used. For Unicode, \xFFFD is used. If the
510 data is supposed to be UTF-8, an optional lexical warning (category
513 =item I<CHECK> = Encode::DIE_ON_ERROR (== 1)
515 If I<CHECK> is 1, methods will die immediately with an error
516 message. so when I<CHECK> is set, you should trap the fatal error
517 with eval{} unless you really want to let it die on error.
519 =item I<CHECK> = Encode::FB_QUIET
521 If I<CHECK> is set to Encode::FB_QUIET, (en|de)code will immediately
522 return proccessed part on error, with data passed via argument
523 overwritten with unproccessed part. This is handy when have to
524 repeatedly call because the source data is chopped in the middle for
525 some reasons, such as fixed-width buffer. Here is a sample code that
529 while(defined(read $fh, $buffer, 256)){
530 # buffer may end in partial character so we append
532 $utf8 .= decode($encoding, $data, ENCODE::FB_QUIET);
533 # $data now contains unprocessed partial character
536 =item I<CHECK> = Encode::FB_WARN
538 This is the same as above, except it warns on error. Handy when you
539 are debugging the mode above.
541 =item perlqq mode (I<CHECK> = Encode::FB_PERLQQ)
543 For encodings that are implemented by Encode::XS, CHECK ==
544 Encode::FB_PERLQQ turns (en|de)code into C<perlqq> fallback mode.
546 When you decode, '\xI<XX>' will be placed where I<XX> is the hex
547 representation of the octet that could not be decoded to utf8. And
548 when you encode, '\x{I<xxxx>}' will be placed where I<xxxx> is the
549 Unicode ID of the character that cannot be found in the character
550 repartoire of the encoding.
554 These modes are actually set via bitmask. here is how FB_XX are laid
555 out. for FB_XX you can import via C<use Encode qw(:fallbacks)> for
556 generic bitmask constants, you can import via
557 C<use Encode qw(:fallback_all)>.
559 FB_DEFAULT FB_CROAK FB_QUIET FB_WARN FB_PERLQQ
562 RETURN_ON_ERR 0x0004 X X
566 =head2 Unemplemented fallback schemes
568 In future you will be able to use a code reference to a callback
569 function for the value of I<CHECK> but its API is still undecided.
571 =head1 Defining Encodings
573 To define a new encoding, use:
575 use Encode qw(define_alias);
576 define_encoding($object, 'canonicalName' [, alias...]);
578 I<canonicalName> will be associated with I<$object>. The object
579 should provide the interface described in L<Encode::Encoding>
580 If more than two arguments are provided then additional
581 arguments are taken as aliases for I<$object> as for C<define_alias>.
583 See L<Encode::Encoding> for more details.
585 =head1 Messing with Perl's Internals
587 The following API uses parts of Perl's internals in the current
588 implementation. As such they are efficient, but may change.
592 =item is_utf8(STRING [, CHECK])
594 [INTERNAL] Test whether the UTF-8 flag is turned on in the STRING.
595 If CHECK is true, also checks the data in STRING for being well-formed
596 UTF-8. Returns true if successful, false otherwise.
598 =item _utf8_on(STRING)
600 [INTERNAL] Turn on the UTF-8 flag in STRING. The data in STRING is
601 B<not> checked for being well-formed UTF-8. Do not use unless you
602 B<know> that the STRING is well-formed UTF-8. Returns the previous
603 state of the UTF-8 flag (so please don't test the return value as
604 I<not> success or failure), or C<undef> if STRING is not a string.
606 =item _utf8_off(STRING)
608 [INTERNAL] Turn off the UTF-8 flag in STRING. Do not use frivolously.
609 Returns the previous state of the UTF-8 flag (so please don't test the
610 return value as I<not> success or failure), or C<undef> if STRING is
618 L<Encode::Supported>,
625 the Perl Unicode Mailing List E<lt>perl-unicode@perl.orgE<gt>
629 This project was originated by Nick Ing-Simmons and later maintained
630 by Dan Kogai E<lt>dankogai@dan.co.jpE<gt>. See AUTHORS for full list
631 of people involved. For any questions, use
632 E<lt>perl-unicode@perl.orgE<gt> so others can share.