Adjusting encoding for files

[Tanktalus]

One of our translations for some JavaScript code came back in the wrong encoding. Instead of being utf8, they came back as ISO8859. The Java guys had no idea how to fix it so...

perl -e 'open $fh, "<:encoding(iso88591)", "messages.js"; $/=undef; $f
+ = <$fh>; open $out, ">:utf8", "messages.js.utf8"; print $out $f;'

I don't want to know the hoops that the CPU went through to translate this file. All I know is that I didn't have to go through those hoops myself. Thanks, perl.

[BrowserUk]

I don't want to know the hoops that the CPU went through to translate this file. All I know is that I didn't have to go through those hoops myself.

Nice story, but those CPU hoops, they don't amount to very much:

C:\test>dir messages.js
20/12/2012  23:59            46,803 messages.js

C:\test>crc32 messages.js
91c9dc22

C:\test>perl -nE"ord()>127 and print for split'', $_" messages.js

C:\test>perl -e "open $fh, '<:encoding(iso88591)', 'messages.js'; $/=u
+ndef; $f = <$fh>; open $out, '>:utf8', 'messages.js.utf8'; print $out
+ $f;"

C:\test>dir messages.*
20/12/2012  23:59            46,803 messages.js
21/12/2012  00:04            46,803 messages.js.utf8

C:\test>perl -nE"ord()>127 and print for split'', $_" messages.js.utf8

C:\test>crc32 messages.js.utf8
91c9dc22

[Tanktalus]

Well, the problem is apparently where you have no characters above 127, because as long as all characters are ordinal less than 128, their encoding doesn't change either in number or in length between utf8 and any other non-ebcdic encoding.

I've "lost" the original file because the updated file is checked in, so I recreated it as *.iso, and I get:

$ perl -nE'ord()>127 and print for split"",$_' *iso | wc -c
32

So, 32 characters with accents or what have you putting its ordinal above 127.

$ ls -l messages.js.*
-rw-r--r-- 1 tanktalus tanktalus 2490 Dec 20 20:57 messages.js.iso
-rw-r--r-- 1 tanktalus tanktalus 2522 Dec 20 20:58 messages.js.utf8

And because they're above 127, when converting to utf8, they'll expand to multiple bytes. In this case, all 32 bytes expand to precisely two bytes (though I think some characters in other languages can be three or four bytes each):

$ perl -nE'ord()>127 and print for split"",$_' *utf8 | wc -c
64

If we were in the situation you gave, there would have been no issue. For all pure-English text (not counting things from other languages, such as "Hawaï" or "déjà vu"), ISO-8859* and UTF8 are bit-for-bit identical. It's only the characters that have separate binary representations between ISO8859* (in this case -1, as that's the encoding most commonly used for French prior to UTF8 taking over) and UTF-8 that caused a problem that had to be resolved, and I used perl to do so.