Name
Encode::ZapCP1252 - Zap Windows Western Gremlins
Synopsis
use Encode::ZapCP1252;
zap_cp1252 $latin1_text;
fix_cp1252 $utf8_text;
Description
Have you ever been processing a Web form submit, assuming that the incoming text was encoded in ISO-8859-1 (Latin-1), only to end up with a bunch of junk because someone pasted in content from Microsoft Word? Well, this is because Microsoft uses a superset of the Latin-1 encoding called "Windows Western" or "CP1252". So mostly things will come out right, but a few things--like curly quotes, m-dashes, elipses, and the like--will not. The differences are well-known; you see a nice chart at documenting the differences on Wikipedia: http://en.wikipedia.org/wiki/Windows-1252.
Of course, that won't really help you. What will help you is to quit using Latin-1 and switch to UTF-8. Then you can just convert from CP1252 to UTF-8 without losing a thing, just like this:
use Encode;
$text = decode 'cp1252', $text, 1;
But I know that there are those of you out there stuck with Latin-1 and who don't want any junk charactrs from Word users, and that's where this module comes in. Its zap_cp1252
function will zap those CP1252 gremlins for you, turning them into their appropriate ASCII approximations.
Another case that can occaisionally come up is when you are using UTF-8, and you're reading in text that claims to be UTF-8, but it still ends up with some CP1252 gremlins mixed in with true UTF-8 characters. I've seen examples of just this sort of thing when processing GMail messages and attempting to insert them into a UTF-8 database. Doesn't work so well. So this module also offers fix_cp1252
, which converts those CP1252 gremlines into their UTF-8 equivalents.
Usage
This module exports two subroutines: zap_cp1252()
and fix_cp1252()
. You use these subroutines like so:
zap_cp1252 $text;
fix_cp1252 $text;
The zap_cp1252()
subroutine performs in place conversions of any CP1252 gremlins into their appropriate ASCII approximations, while fix_cp1252()
converts them, in place, into their UTF-8 equilvalents.
Note that because the conversion happens in place, the data to be converted cannot be a string constant; it must be a scalar variable.
Conversion Table
Here's how the characters are converted to ASCII and UTF-8. The ASCII conversions are not perfect, but they should be good enough for general cleanup. If you want perfect, switch to UTF-8 and be done with it!
Hex | Char | ASCII | UTF-8 Name
-----+-------+-------+-------------------------------------------
0x80 | € | e | EURO SIGN
0x82 | ‚ | , | SINGLE LOW-9 QUOTATION MARK
0x83 | ƒ | f | LATIN SMALL LETTER F WITH HOOK
0x84 | „ | ,, | DOUBLE LOW-9 QUOTATION MARK
0x85 | … | ... | HORIZONTAL ELLIPSIS
0x86 | † | + | DAGGER
0x87 | ‡ | ++ | DOUBLE DAGGER
0x88 | ˆ | ^ | MODIFIER LETTER CIRCUMFLEX ACCENT
0x89 | ‰ | % | PER MILLE SIGN
0x8a | Š | S | LATIN CAPITAL LETTER S WITH CARON
0x8b | ‹ | < | SINGLE LEFT-POINTING ANGLE QUOTATION MARK
0x8c | Œ | OE | LATIN CAPITAL LIGATURE OE
0x8e | Ž | Z | LATIN CAPITAL LETTER Z WITH CARON
0x91 | ‘ | ' | LEFT SINGLE QUOTATION MARK
0x92 | ’ | ' | RIGHT SINGLE QUOTATION MARK
0x93 | “ | " | LEFT DOUBLE QUOTATION MARK
0x94 | ” | " | RIGHT DOUBLE QUOTATION MARK
0x95 | • | * | BULLET
0x96 | – | - | EN DASH
0x97 | — | -- | EM DASH
0x98 | ˜ | ~ | SMALL TILDE
0x99 | ™ | (tm) | TRADE MARK SIGN
0x9a | š | s | LATIN SMALL LETTER S WITH CARON
0x9b | › | > | SINGLE RIGHT-POINTING ANGLE QUOTATION MARK
0x9c | œ | oe | LATIN SMALL LIGATURE OE
0x9e | ž | z | LATIN SMALL LETTER Z WITH CARON
0x9f | Ÿ | Y | LATIN CAPITAL LETTER Y WITH DIAERESIS
Changing the Table
Don't like these conversions? You can modify them to your hearts content by accessing this module's internal conversion tables. For example, if you wanted zap_cp1252()
to use an uppercase E for the euro sign, just do this:
$Encode::ZapCP1252::ascii_for{"\x80"} = 'E';
Or if, for some bizarre reason, you wanted the UTF-8 equivalent for a bullet converted by fix_cp1252()
to really be an asterisk (why would you? Just use zap_cp1252
for that!), you can do this:
$Encode::ZapCP1252::utf8_for{"\x95"} = '*';
Just remember, this is a global change, so be careful if your code uses this module elsewhere. Of course, it shouldn't really be doing that. These functions are just for cleaning up messes in one spot in your code, not for makeing a fundamental part of your text handling. For that, use Encode.
See Also
Support
This module is stored in an open repository at the following address:
https://svn.kineticode.com/Encode-ZapCP1252/trunk/
Patches against Encode::ZapCP1252 are welcome. Please send bug reports to <bug-encode-zapcp1252@rt.cpan.org>.
Author
David Wheeler <david@kineticode.com>
Acknowledgements
My thanks to Sean Burke for sending me his original method for converting CP1252 gremlins to more-or-less appropriate ASCII characters.
Copyright and License
Copyright (c) 2005-2008 Kineticode, Inc. Some Rights Reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.