package encoding;
-our $VERSION = do { my @r = (q$Revision: 1.28 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
+our $VERSION = do { my @r = (q$Revision: 1.33 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
use Encode;
use strict;
}
}
-our $HAS_PERLIO_ENCODING;
-
-eval { require PerlIO::encoding; };
-if ($@){
- $HAS_PERLIO_ENCODING = 0;
-}else{
- $HAS_PERLIO_ENCODING = 1;
- binmode(STDIN);
+our $HAS_PERLIO = 0;
+eval { require PerlIO::encoding };
+unless ($@){
+ $HAS_PERLIO = (PerlIO::encoding->VERSION >= 0.02);
}
sub import {
}
unless ($arg{Filter}){
${^ENCODING} = $enc; # this is all you need, actually.
- $HAS_PERLIO_ENCODING or return 1;
+ $HAS_PERLIO or return 1;
for my $h (qw(STDIN STDOUT)){
if ($arg{$h}){
unless (defined find_encoding($arg{$h})) {
require Carp;
Carp::croak "Unknown encoding for $h, '$arg{$h}'";
}
- eval qq{ binmode($h, ":encoding($arg{$h})") };
+ eval { binmode($h, ":encoding($arg{$h})") };
}else{
unless (exists $arg{$h}){
- eval qq{ binmode($h, ":encoding($name)") };
+ eval {
+ no warnings 'uninitialized';
+ binmode($h, ":encoding($name)");
+ };
}
}
if ($@){
1;
__END__
+
=pod
=head1 NAME
-encoding - allows you to write your script in non-asii or non-utf8
+encoding - allows you to write your script in non-ascii or non-utf8
=head1 SYNOPSIS
+ use encoding "greek"; # Perl like Greek to you?
use encoding "euc-jp"; # Jperl!
- # or you can even do this if your shell supports euc-jp
+ # or you can even do this if your shell supports your native encoding
- > perl -Mencoding=euc-jp -e '...'
+ perl -Mencoding=latin2 -e '...' # Feeling centrally European?
+ perl -Mencoding=euc-kr -e '...' # Or Korean?
# or from the shebang line
- #!/your/path/to/perl -Mencoding=euc-jp
+ #!/your/path/to/perl -Mencoding="8859-6" # Arabian Nights
+ #!/your/path/to/perl -Mencoding=big5 # Taiwanese
# more control
- # A simple euc-jp => utf-8 converter
- use encoding "euc-jp", STDOUT => "utf8"; while(<>){print};
+ # A simple euc-cn => utf-8 converter
+ use encoding "euc-cn", STDOUT => "utf8"; while(<>){print};
# "no encoding;" supported (but not scoped!)
no encoding;
=head1 ABSTRACT
-Perl 5.6.0 has introduced Unicode support. You could apply
-C<substr()> and regexes even to complex CJK characters -- so long as
-the script was written in UTF-8. But back then text editors that
-support UTF-8 was still rare and many users rather chose to writer
-scripts in legacy encodings, given up whole new feature of Perl 5.6.
+Let's start with a bit of history: Perl 5.6.0 introduced Unicode
+support. You could apply C<substr()> and regexes even to complex CJK
+characters -- so long as the script was written in UTF-8. But back
+then, text editors that supported UTF-8 were still rare and many users
+instead chose to write scripts in legacy encodings, giving up a whole
+new feature of Perl 5.6.
-With B<encoding> pragma, you can write your script in any encoding you like
-(so long as the C<Encode> module supports it) and still enjoy Unicode
-support. You can write a code in EUC-JP as follows;
+Rewind to the future: starting from perl 5.8.0 with the B<encoding>
+pragma, you can write your script in any encoding you like (so long
+as the C<Encode> module supports it) and still enjoy Unicode support.
+You can write code in EUC-JP as follows:
my $Rakuda = "\xF1\xD1\xF1\xCC"; # Camel in Kanji
#<-char-><-char-> # 4 octets
s/\bCamel\b/$Rakuda/;
And with C<use encoding "euc-jp"> in effect, it is the same thing as
-the code in UTF-8 as follow.
+the code in UTF-8:
- my $Rakuda = "\x{99F1}\x{99DD}"; # who Unicode Characters
+ my $Rakuda = "\x{99F1}\x{99DD}"; # two Unicode Characters
s/\bCamel\b/$Rakuda/;
-The B<encoding> pragma also modifies the file handle disciplines of
+The B<encoding> pragma also modifies the filehandle disciplines of
STDIN, STDOUT, and STDERR to the specified encoding. Therefore,
use encoding "euc-jp";
$message =~ s/\bCamel\b/$Rakuda/;
print $message;
-Will print "\xF1\xD1\xF1\xCC is the symbol of perl.\n", not
-"\x{99F1}\x{99DD} is the symbol of perl.\n".
+Will print "\xF1\xD1\xF1\xCC is the symbol of perl.\n",
+not "\x{99F1}\x{99DD} is the symbol of perl.\n".
-You can override this by giving extra arguments. See below.
+You can override this by giving extra arguments; see below.
=head1 USAGE
=item use encoding [I<ENCNAME>] ;
-Sets the script encoding to I<ENCNAME> and file handle disciplines of
-STDIN, STDOUT are set to ":encoding(I<ENCNAME>)". Note STDERR will not
-be changed.
+Sets the script encoding to I<ENCNAME>. Filehandle disciplines of
+STDIN and STDOUT are set to ":encoding(I<ENCNAME>)". Note that STDERR
+will not be changed.
If no encoding is specified, the environment variable L<PERL_ENCODING>
-is consulted. If no encoding can be found, C<Unknown encoding 'I<ENCNAME>'>
-error will be thrown.
+is consulted. If no encoding can be found, the error C<Unknown encoding
+'I<ENCNAME>'> will be thrown.
Note that non-STD file handles remain unaffected. Use C<use open> or
C<binmode> to change disciplines of those.
=item use encoding I<ENCNAME> [ STDIN =E<gt> I<ENCNAME_IN> ...] ;
-You can also individually set encodings of STDIN and STDOUT via
-STDI<FH> =E<gt> I<ENCNAME_FH> form. In this case, you cannot omit the
-first I<ENCNAME>. C<STDI<FH> =E<gt> undef> turns IO transcoding
+You can also individually set encodings of STDIN and STDOUT via the
+C<< STDIN => I<ENCNAME> >> form. In this case, you cannot omit the
+first I<ENCNAME>. C<< STDIN => undef >> turns the IO transcoding
completely off.
=item no encoding;
-Unsets the script encoding and the disciplines of STDIN, STDOUT are
-reset to ":raw".
+Unsets the script encoding. The disciplines of STDIN, STDOUT are
+reset to ":raw" (the default unprocessed raw stream of bytes).
=back
=head2 NOT SCOPED
The pragma is a per script, not a per block lexical. Only the last
-C<use encoding> or C<matters, and it affects B<the whole script>.
-Though <no encoding> pragma is supported and C<use encoding> can
-appear as many times as you want in a given script, the multiple use
+C<use encoding> or C<no encoding> matters, and it affects B<the whole script>.
+However, the <no encoding> pragma is supported and C<use encoding> can
+appear as many times as you want in a given script. The multiple use
of this pragma is discouraged.
=head2 DO NOT MIX MULTIPLE ENCODINGS
"\xDF\x{100}" =~ /\x{3af}\x{100}/
-since the C<\xDF> on the left will B<not> be upgraded to C<\x{3af}>
-because of the C<\x{100}> on the left. You should not be mixing your
-legacy data and Unicode in the same string.
+since the C<\xDF> (ISO 8859-7 GREEK SMALL LETTER IOTA WITH TONOS) on
+the left will B<not> be upgraded to C<\x{3af}> (Unicode GREEK SMALL
+LETTER IOTA WITH TONOS) because of the C<\x{100}> on the left. You
+should not be mixing your legacy data and Unicode in the same string.
This pragma also affects encoding of the 0x80..0xFF code point range:
normally characters in that range are left as eight-bit bytes (unless
gets UTF-8 encoded.
After all, the best thing about this pragma is that you don't have to
-resort to \x... just to spell your name in native encoding. So feel
-free to put your strings in your encoding in quotes and regexes.
+resort to \x{....} just to spell your name in a native encoding.
+So feel free to put your strings in your encoding in quotes and
+regexes.
-=head1 NON-ASCII Identifiers and Filter option
+=head1 Non-ASCII Identifiers and Filter option
-The magic of C<use encoding> is not applied to the names of identifiers.
-In order to make C<${"4eba"}++> ($man++, where man is a single ideograph)
-work, you still need to write your script in UTF-8 or use a source filter.
+The magic of C<use encoding> is not applied to the names of
+identifiers. In order to make C<${"\x{4eba}"}++> ($human++, where human
+is a single Han ideograph) work, you still need to write your script
+in UTF-8 or use a source filter.
-In other words, the same restriction as Jperl applies.
+In other words, the same restriction as with Jperl applies.
-If you dare experiment, however, you can try Fitlter option.
+If you dare to experiment, however, you can try the Filter option.
=over 4
=item use encoding I<ENCNAME> Filter=E<gt>1;
-This turns encoding pragma into source filter. While the default
+This turns the encoding pragma into a source filter. While the default
approach just decodes interpolated literals (in qq() and qr()), this
-will apply source filter to entire source code. In this case, STDIN
-and STDOUT remain untouched.
+will apply a source filter to the entire source code. In this case,
+STDIN and STDOUT remain untouched.
=back
-What does this mean? Your source code behaves as if it is written
-in UTF-8. So even if your editor only supports Shift_JIS, for
-example. You can still try examples in Chapter 15 of
-C<Programming Perl, 3rd Ed.> For instance, you can use UTF-8
-identifiers.
+What does this mean? Your source code behaves as if it is written in
+UTF-8. So even if your editor only supports Shift_JIS, for example,
+you can still try examples in Chapter 15 of C<Programming Perl, 3rd
+Ed.>. For instance, you can use UTF-8 identifiers.
This option is significantly slower and (as of this writing) non-ASCII
identifiers are not very stable WITHOUT this option and with the
source code written in UTF-8.
-To make your script in legacy encoding work with minimum effort, do
-not use Filter=E<gt>1
-
+To make your script in legacy encoding work with minimum effort,
+do not use Filter=E<gt>1.
=head1 EXAMPLE - Greekperl
use encoding "iso 8859-7";
- # The \xDF of ISO 8859-7 (Greek) is \x{3af} in Unicode.
+ # \xDF in ISO 8859-7 (Greek) is \x{3af} in Unicode.
$a = "\xDF";
$b = "\x{100}";
print "exa\n" if "\x{3af}" cmp pack("C", 0xdf) == 0;
# ... but pack/unpack C are not affected, in case you still
- # want back to your native encoding
+ # want to go back to your native encoding
print "zetta\n" if unpack("C", (pack("C", 0xdf))) == 0xdf;
=head1 KNOWN PROBLEMS
-For native multibyte encodings (either fixed or variable length)
+For native multibyte encodings (either fixed or variable length),
the current implementation of the regular expressions may introduce
-recoding errors for longer regular expression literals than 127 bytes.
+recoding errors for regular expression literals longer than 127 bytes.
The encoding pragma is not supported on EBCDIC platforms.
-(Porters wanted.)
+(Porters who are willing and able to remove this limitation are
+welcome.)
=head1 SEE ALSO
projects / p5sagit/p5-mst-13.2.git / blobdiff