[537] | 1 | ###########################################################################
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| 2 | #
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| 3 | # unicode.pm --
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| 4 | # A component of the Greenstone digital library software
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| 5 | # from the New Zealand Digital Library Project at the
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| 6 | # University of Waikato, New Zealand.
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| 7 | #
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| 8 | # Copyright (C) 1999 New Zealand Digital Library Project
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| 9 | #
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| 10 | # This program is free software; you can redistribute it and/or modify
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| 11 | # it under the terms of the GNU General Public License as published by
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| 12 | # the Free Software Foundation; either version 2 of the License, or
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| 13 | # (at your option) any later version.
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| 14 | #
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| 15 | # This program is distributed in the hope that it will be useful,
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| 16 | # but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 17 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 18 | # GNU General Public License for more details.
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| 19 | #
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| 20 | # You should have received a copy of the GNU General Public License
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| 21 | # along with this program; if not, write to the Free Software
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| 22 | # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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| 23 | #
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| 24 | ###########################################################################
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| 25 |
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[71] | 26 | # useful functions for dealing with Unicode
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| 27 |
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| 28 | # Unicode strings are stored as arrays of scalars as perl
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| 29 | # lacks characters are 8-bit (currently)
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| 30 |
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| 31 | package unicode;
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| 32 |
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[1227] | 33 | %translations = ();
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[71] | 34 |
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[1223] | 35 | # ascii2unicode takes an (extended) ascii string (ISO-8859-1)
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| 36 | # and returns a unicode array.
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[73] | 37 | sub ascii2unicode {
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| 38 | my ($in) = @_;
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| 39 | my $out = [];
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| 40 |
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| 41 | my $i = 0;
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| 42 | my $len = length($in);
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| 43 | while ($i < $len) {
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| 44 | push (@$out, ord(substr ($in, $i, 1)));
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| 45 | $i++;
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| 46 | }
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| 47 |
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| 48 | return $out;
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| 49 | }
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| 50 |
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[1223] | 51 | # arabic2unicode takes an 8 bit Arabic string (ISO-8859-6)
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| 52 | # and returns a unicode array
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| 53 | sub arabic2unicode {
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| 54 | my ($in) = @_;
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| 55 | my $out = [];
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[73] | 56 |
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[1223] | 57 | my $i = 0;
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| 58 | my $len = length($in);
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| 59 | while ($i < $len) {
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| 60 | my $c = ord(substr ($in, $i, 1));
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| 61 | $c += (1567-191) if ($c >= 0x80);
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| 62 | push (@$out, $c);
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| 63 | $i++;
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| 64 | }
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| 65 |
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| 66 | return $out;
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| 67 | }
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| 68 |
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[1227] | 69 | # windows2unicode takes a windows encoding (e.g. Windows 1256 (Arabic))
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| 70 | # and returns a unicode array. These encodings are similar to but not
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| 71 | # identical to the corresponding ISO-8859 encodings.
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| 72 | #
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| 73 | # The map files for these encodings should be in unicode/MAPPINGS/WINDOWS
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| 74 | sub windows2unicode {
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| 75 | my ($encoding, $in) = @_;
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| 76 | my $out = [];
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| 77 |
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| 78 | my $mapfile = &util::filename_cat($ENV{'GSDLHOME'}, "unicode", "MAPPINGS",
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| 79 | "WINDOWS", "$encoding.TXT");
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| 80 | return $out unless &loadmapping ($encoding, $mapfile);
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| 81 |
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| 82 | my $i = 0;
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| 83 | my $len = length($in);
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| 84 | while ($i < $len) {
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| 85 | my $c = ord(substr ($in, $i, 1));
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| 86 | $c = $translations{"$encoding-unicode"}->{$c} if ($c >= 0x80);
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| 87 | push (@$out, $c);
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| 88 | $i++;
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| 89 | }
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| 90 |
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| 91 | return $out;
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| 92 | }
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| 93 |
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| 94 |
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[73] | 95 | # ascii2utf8 takes a (extended) ascii string and
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| 96 | # returns a UTF-8 encoded string. This is just
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| 97 | # a faster version of "&unicode2utf8(&ascii2unicode($str));"
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| 98 | sub ascii2utf8 {
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| 99 | my ($in) = @_;
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| 100 | my $out = "";
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| 101 |
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| 102 | my ($c);
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| 103 | my $i = 0;
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| 104 | my $len = length($in);
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| 105 | while ($i < $len) {
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| 106 | $c = ord (substr ($in, $i, 1));
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| 107 | if ($c < 0x80) {
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| 108 | # ascii character
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| 109 | $out .= chr ($c);
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| 110 |
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| 111 | } else {
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| 112 | # extended ascii character
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| 113 | $out .= chr (0xc0 + (($c >> 6) & 0x1f));
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| 114 | $out .= chr (0x80 + ($c & 0x3f));
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| 115 | }
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| 116 | $i++;
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| 117 | }
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| 118 |
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| 119 | return $out;
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| 120 | }
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| 121 |
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| 122 |
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[71] | 123 | # unicode2utf8 takes a unicode array as input and encodes it
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| 124 | # using utf-8
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| 125 | sub unicode2utf8 {
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| 126 | my ($in) = @_;
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| 127 | my $out = "";
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| 128 |
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| 129 | foreach $num (@$in) {
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| 130 | if ($num < 0x80) {
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| 131 | $out .= chr ($num);
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| 132 |
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| 133 | } elsif ($num < 0x800) {
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| 134 | $out .= chr (0xc0 + (($num >> 6) & 0x1f));
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| 135 | $out .= chr (0x80 + ($num & 0x3f));
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| 136 |
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| 137 | } elsif ($num < 0xFFFF) {
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| 138 | $out .= chr (0xe0 + (($num >> 12) & 0xf));
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| 139 | $out .= chr (0x80 + (($num >> 6) & 0x3f));
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| 140 | $out .= chr (0x80 + ($num & 0x3f));
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| 141 |
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| 142 | } else {
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| 143 | # error, don't encode anything
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| 144 | die;
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| 145 | }
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| 146 | }
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| 147 |
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| 148 | return $out;
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| 149 | }
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| 150 |
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| 151 |
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| 152 | # utf82unicode takes a utf-8 string and produces a unicode
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| 153 | # array
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| 154 | sub utf82unicode {
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| 155 | my ($in) = @_;
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| 156 | my $out = [];
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| 157 |
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| 158 | my $i = 0;
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| 159 | my ($c1, $c2, $c3);
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| 160 | $len = length($in);
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| 161 | while ($i < $len) {
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| 162 | if (($c1 = ord(substr ($in, $i, 1))) < 0x80) {
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| 163 | # normal ascii character
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| 164 | push (@$out, $c1);
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| 165 |
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| 166 | } elsif ($c1 < 0xc0) {
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| 167 | # error, was expecting the first byte of an
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| 168 | # encoded character. Do nothing.
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| 169 |
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| 170 | } elsif ($c1 < 0xe0 && $i+1 < $len) {
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| 171 | # an encoded character with two bytes
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| 172 | $c2 = ord (substr ($in, $i+1, 1));
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| 173 | if ($c2 >= 0x80 && $c2 < 0xc0) {
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| 174 | # everything looks ok
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| 175 | push (@$out, ((($c1 & 0x1f) << 6) +
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| 176 | ($c2 & 0x3f)));
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| 177 | $i++; # gobbled an extra byte
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| 178 | }
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| 179 |
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| 180 | } elsif ($c1 < 0xf0 && $i+2 < $len) {
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| 181 | # an encoded character with three bytes
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| 182 | $c2 = ord (substr ($in, $i+1, 1));
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| 183 | $c3 = ord (substr ($in, $i+2, 1));
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| 184 | if ($c2 >= 0x80 && $c2 < 0xc0 &&
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| 185 | $c3 >= 0x80 && $c3 < 0xc0) {
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| 186 | # everything looks ok
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| 187 | push (@$out, ((($c1 & 0xf) << 12) +
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| 188 | (($c2 & 0x3f) << 6) +
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| 189 | ($c3 & 0x3f)));
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| 190 |
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| 191 | $i += 2; # gobbled an extra two bytes
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| 192 | }
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| 193 |
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| 194 | } else {
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| 195 | # error, only decode Unicode characters not full UCS.
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| 196 | # Do nothing.
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| 197 | }
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| 198 |
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| 199 | $i++;
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| 200 | }
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| 201 |
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| 202 | return $out;
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| 203 | }
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| 204 |
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| 205 |
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| 206 | # unicode2ucs2 takes a unicode array and produces a UCS-2
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| 207 | # unicode string (every two bytes forms a unicode character)
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| 208 | sub unicode2ucs2 {
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| 209 | my ($in) = @_;
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| 210 | my $out = "";
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| 211 |
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| 212 | foreach $num (@$in) {
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| 213 | $out .= chr (($num & 0xff00) >> 8);
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| 214 | $out .= chr ($num & 0xff);
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| 215 | }
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| 216 |
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| 217 | return $out;
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| 218 | }
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| 219 |
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| 220 |
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| 221 | # ucs22unicode takes a UCS-2 string and produces a unicode array
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| 222 | sub ucs22unicode {
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| 223 | my ($in) = @_;
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| 224 | my $out = [];
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| 225 |
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| 226 | my $i = 0;
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| 227 | my $len = length ($in);
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| 228 | while ($i+1 < $len) {
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| 229 | push (@$out, ord (substr($in, $i, 1)) << 8 +
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| 230 | ord (substr($in, $i+1, 1)));
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| 231 |
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| 232 | $i ++;
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| 233 | }
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| 234 |
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| 235 | return $out;
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| 236 | }
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| 237 |
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[1227] | 238 | # loadmapping expects the mapfile to contain (at least) two
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| 239 | # tab-separated fields. The first field is the mapped value
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| 240 | # and the second field is the unicode value.
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| 241 | #
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| 242 | # It returns 1 if successful, 0 if unsuccessful
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| 243 | sub loadmapping {
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| 244 | my ($encoding, $mapfile) = @_;
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| 245 |
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| 246 | my $to = "$encoding-unicode";
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| 247 | my $from = "unicode-$encoding";
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[71] | 248 |
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[1227] | 249 | # check to see if the encoding has already been loaded
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| 250 | if (defined $translations{$to} && defined $translations{$from}) {
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| 251 | return 1;
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| 252 | }
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| 253 |
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| 254 | if (!open (MAPFILE, $mapfile)) {
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| 255 | print STDERR "ERROR: unable to load mapfile $mapfile\n";
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| 256 | return 0;
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| 257 | }
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| 258 |
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| 259 | my ($line, @line);
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| 260 | $translations{$to} = {};
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| 261 | $translations{$from} = {};
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| 262 | while (defined ($line = <MAPFILE>)) {
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| 263 | # remove comments
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| 264 | $line =~ s/\#.*$//;
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| 265 | next unless $line =~ /\S/;
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| 266 |
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| 267 | # split the line into fields and do a few
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| 268 | # simple sanity checks
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| 269 | @line = split (/\t/, $line);
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| 270 | next unless (scalar(@line) >= 2 &&
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| 271 | $line[0] =~ /^0x/ &&
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| 272 | $line[1] =~ /^0x/);
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| 273 |
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| 274 | my $a = hex($line[0]);
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| 275 | my $b = hex($line[1]);
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| 276 |
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| 277 | $translations{$to}->{$a} = $b;
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| 278 | $translations{$from}->{$b} = $a;
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| 279 | }
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| 280 |
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| 281 | close (MAPFILE);
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| 282 |
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| 283 | return 1;
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| 284 | }
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| 285 |
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| 286 |
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[71] | 287 | 1;
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