JezK
Edit File: HZ.pm
package Encode::CN::HZ; use strict; use warnings; use utf8 (); use vars qw($VERSION); $VERSION = do { my @r = ( q$Revision: 2.10 $ =~ /\d+/g ); sprintf "%d." . "%02d" x $#r, @r }; use Encode qw(:fallbacks); use parent qw(Encode::Encoding); __PACKAGE__->Define('hz'); # HZ is a combination of ASCII and escaped GB, so we implement it # with the GB2312(raw) encoding here. Cf. RFCs 1842 & 1843. # not ported for EBCDIC. Which should be used, "~" or "\x7E"? sub needs_lines { 1 } sub decode ($$;$) { my ( $obj, $str, $chk ) = @_; return undef unless defined $str; my $GB = Encode::find_encoding('gb2312-raw'); my $ret = substr($str, 0, 0); # to propagate taintedness my $in_ascii = 1; # default mode is ASCII. while ( length $str ) { if ($in_ascii) { # ASCII mode if ( $str =~ s/^([\x00-\x7D\x7F]+)// ) { # no '~' => ASCII $ret .= $1; # EBCDIC should need ascii2native, but not ported. } elsif ( $str =~ s/^\x7E\x7E// ) { # escaped tilde $ret .= '~'; } elsif ( $str =~ s/^\x7E\cJ// ) { # '\cJ' == LF in ASCII 1; # no-op } elsif ( $str =~ s/^\x7E\x7B// ) { # '~{' $in_ascii = 0; # to GB } else { # encounters an invalid escape, \x80 or greater last; } } else { # GB mode; the byte ranges are as in RFC 1843. no warnings 'uninitialized'; if ( $str =~ s/^((?:[\x21-\x77][\x21-\x7E])+)// ) { my $prefix = $1; $ret .= $GB->decode( $prefix, $chk ); } elsif ( $str =~ s/^\x7E\x7D// ) { # '~}' $in_ascii = 1; } else { # invalid last; } } } $_[1] = '' if $chk; # needs_lines guarantees no partial character return $ret; } sub cat_decode { my ( $obj, undef, $src, $pos, $trm, $chk ) = @_; my ( $rdst, $rsrc, $rpos ) = \@_[ 1 .. 3 ]; my $GB = Encode::find_encoding('gb2312-raw'); my $ret = ''; my $in_ascii = 1; # default mode is ASCII. my $ini_pos = pos($$rsrc); substr( $src, 0, $pos ) = ''; my $ini_len = bytes::length($src); # $trm is the first of the pair '~~', then 2nd tilde is to be removed. # XXX: Is better C<$src =~ s/^\x7E// or die if ...>? $src =~ s/^\x7E// if $trm eq "\x7E"; while ( length $src ) { my $now; if ($in_ascii) { # ASCII mode if ( $src =~ s/^([\x00-\x7D\x7F])// ) { # no '~' => ASCII $now = $1; } elsif ( $src =~ s/^\x7E\x7E// ) { # escaped tilde $now = '~'; } elsif ( $src =~ s/^\x7E\cJ// ) { # '\cJ' == LF in ASCII next; } elsif ( $src =~ s/^\x7E\x7B// ) { # '~{' $in_ascii = 0; # to GB next; } else { # encounters an invalid escape, \x80 or greater last; } } else { # GB mode; the byte ranges are as in RFC 1843. if ( $src =~ s/^((?:[\x21-\x77][\x21-\x7F])+)// ) { $now = $GB->decode( $1, $chk ); } elsif ( $src =~ s/^\x7E\x7D// ) { # '~}' $in_ascii = 1; next; } else { # invalid last; } } next if !defined $now; $ret .= $now; if ( $now eq $trm ) { $$rdst .= $ret; $$rpos = $ini_pos + $pos + $ini_len - bytes::length($src); pos($$rsrc) = $ini_pos; return 1; } } $$rdst .= $ret; $$rpos = $ini_pos + $pos + $ini_len - bytes::length($src); pos($$rsrc) = $ini_pos; return ''; # terminator not found } sub encode($$;$) { my ( $obj, $str, $chk ) = @_; return undef unless defined $str; my $GB = Encode::find_encoding('gb2312-raw'); my $ret = substr($str, 0, 0); # to propagate taintedness; my $in_ascii = 1; # default mode is ASCII. no warnings 'utf8'; # $str may be malformed UTF8 at the end of a chunk. while ( length $str ) { if ( $str =~ s/^([[:ascii:]]+)// ) { my $tmp = $1; $tmp =~ s/~/~~/g; # escapes tildes if ( !$in_ascii ) { $ret .= "\x7E\x7D"; # '~}' $in_ascii = 1; } $ret .= pack 'a*', $tmp; # remove UTF8 flag. } elsif ( $str =~ s/(.)// ) { my $s = $1; my $tmp = $GB->encode( $s, $chk || 0 ); last if !defined $tmp; if ( length $tmp == 2 ) { # maybe a valid GB char (XXX) if ($in_ascii) { $ret .= "\x7E\x7B"; # '~{' $in_ascii = 0; } $ret .= $tmp; } elsif ( length $tmp ) { # maybe FALLBACK in ASCII (XXX) if ( !$in_ascii ) { $ret .= "\x7E\x7D"; # '~}' $in_ascii = 1; } $ret .= $tmp; } } else { # if $str is malformed UTF8 *and* if length $str != 0. last; } } $_[1] = $str if $chk; # The state at the end of the chunk is discarded, even if in GB mode. # That results in the combination of GB-OUT and GB-IN, i.e. "~}~{". # Parhaps it is harmless, but further investigations may be required... if ( !$in_ascii ) { $ret .= "\x7E\x7D"; # '~}' $in_ascii = 1; } utf8::encode($ret); # https://rt.cpan.org/Ticket/Display.html?id=35120 return $ret; } 1; __END__ =head1 NAME Encode::CN::HZ -- internally used by Encode::CN =cut