I have a file. I don't know how it was processed. It's probably a double encoding. I've found this link about double encoding that solved almost my problem:
http://www.spamusers.com/encoding.htm
It has all the double encodings substitutions to do like:
À àÁ
 Â
Unfortnately I still others weird characters like:
ú
ç
ö
Do you have an idea on how to clean these weird characters? For the ones I know I've just made a bash script and I've just replaced them. But I don't know how to recognize the others. I'm running on linux so if you have some magic commands I would like that.
The “double encodings substitutions” page that you link to seems to contain mappings meant to fix character data that has been doubly UTF-8 encoded. Thus, the proper fixing routine would be to reverse such mappings and see if the result makes sense.
For example, if you take A with grave accent, À, U+00C0, and UTF-8 encode it, you get the bytes C3 A0. If these are then mistakenly understood as single-byte encodings according to windows-1252 for example, you get the characters U+00C3 U+00A0 (letter à and no-break space). If these are then UTF-8 encoded, you get C3 83 for the former and C2 80 for the latter. If these bytes in turn are interpreted according to windows-1252, you get À as on the page.
But you don’t actually have “À”, do you? You have some digital data, bytes, which display that way if interpreted according to windows-1252. But that would be a wrong interpretation.
You should first read the data as UTF-8 encoded, decode it to characters, checking that all codes are less than 100 hexadecimal (if not, there’s yet another error involved somewhere), then UTF-9 decode again.
Related
Does URL encoding guarantee for all encoded characters (after the encoding process) to be printable (visible)? Within its specification and scope? "Printable" here is defined as "visible on paper". Unfortunately could not find any documents mentioning anything similar online
URL encoding uses a very limited set of characters (probably 7-bit ascii), hence is always printable.
All 8-bit codes, plus all of these: !"# $%&' ()*+ ,/:; <=>? #[\] ^``{| }~ are turned into something else.
Perhaps importantly, but confusing: a single space is turned into +.
The goal of the encoding is to avoid parsing problems in URLs:
HTTP://example.com/blah.php?my_url=example.com?confusion reighn&x=(a+b)
The stuff after my_url= should have been encoded.
If we type into firefox or chrome
http://☃.net/
It takes us to
http://xn--n3h.net/
Which is a mirror of unicodesnowmanforyou.com
What I don't understand is by what rules the unicode snowman can decode to xn--n3h, it doesn't look anything like utf-8 or urlencoding.
I think I found a hint while mucking around in python3, because:
>>> '☃'.encode('punycode')
b'n3h'
But I still don't understand the xn-- part. How are domain names internationalised, what is the standard and where is this stuff documented?
It uses an encoding scheme called Punycode (as you've already discovered from the Python testing you've done), capable of representing Unicode characters in ASCII-only format.
Each label (delimited by dots, so get.me.a.coffee.com has five labels) that contains Unicode characters is encoded in Punycode and prefixed with the string xn--.
The label encoding first copies all the ASCII characters, then appends the encoded Unicode characters. The Unicode characters are always after the final - in the label, so one is added after the ASCII characters if needed.
More detail can be found in this page over at the w3 site, and in RFC 3987. For details on how Punycode actually encodes labels, see the Wikipedia page.
I was curious if I should encode urls with ASCII or UTF-8. I was under the belief that urls cannot have non-ASCII characters, but someone told me they can have UTF-8, and I searched around and couldn't quite find which one is true. Does anyone know?
There are two parts to this, but they both amount to "yes".
With IDNA, it is possible to register domain names using the full Unicode repertoire (with a few minor twists to prevent ambiguities and abuse).
The path part is not strictly regulated, but it's possible to encode arbitrary strings in the path. The browser could opt to display a human-readable rendering rather than an encoded path. However, this requires heuristics, as there is no way to specify the character set and encoding of the path.
So, http://xn--msic-0ra.example/mot%C3%B6rhead is a (fictional example, not entirely correct) computer-readable encoded URL which could be displayed to the user as http://müsic.example/motörhead. The domain name is encoded as xn--msic-0ra.example in something called Punycode, and the path contains the label "motörhead" encoded as UTF-8 and URL encoded (the Unicode code point U+00F6 is reprecented with the two bytes 0xC3 0xB6 in UTF-8).
The path could also be mot%F6rhead which is the same label in Latin-1. In this case, deducing a reasonable human-readable representation would be much harder, but perhaps the context of the surrounding characters could offer enough hints for a good guess.
In isolation, %F6 could be pretty much anything, and %C3%B6 could be e.g. UTF-16.
The question is ,I hope,simple for someone who knows about character encoding.
This is my site.
http://www.football-tennis-stats.com/index.php/stats/display/tennis
Online, the character set is wrong ,I get this weird Â,while on localhost everything is allright.
I know there is a lot of good reading to be done on this subject,but I don't even know where to start.
There does not seem to be any character encoding issue, just spurious data, namely bytes 0xC3 0x82, which represent the character  when interpreted in UTF-8, which is the declared encoding. Otherwise, the content seems to be all ASCII, because the names are in “internationalized”, i.e. anglicized form, e.g. Djokovic instead of Đoković, Soderling instead of Söderling etc. With this data, it does not matter much how you declare its encoding, since ASCII characters mostly have the same representation anyway.
I have no idea where the bytes come from, but they seem to appear systematically between a comma and a space, so it’s apparently something in the code that generates the table.
I have some link resources with none latin characters like åäö
These are usually user uploaded files
The problem is that i am not successfull in encoding them
using filename.encodeAsURL seems to not encode it the right way
For example the character ö is turned into o%CC%88
Testing to type the same thing in firefox and copy the contents gives %C3%B6
What are the difference between these encodings and what should i use to get the correct encoding??
Both encodings are correct. You are actually seeing the encoding of two different strings.
The key here is noticing the o at the beginning of the string:
o%CC%88 is the letter o followed by Unicode Character Combining Diaeresis, which combines with the previous character when rendered.
%C3%B6 is Unicode Character Latin Small O With Diaeresis.
What you are seeing is that in the first case, the string entered is something like these two characters: o ¨, which are actually rendered as ö.
In the second case, it's the actual character ö.
My guess is you are seeing the difference between two different inputs.
Update based on below discussion: If you are dynamically processing Unicode characters, and you do not have control over the input methods, you can try to normalize the Unicode, using java.text.Normalizer (Java 1.6 or newer).
Normalizing attempts to ensure that all characters are consistently represented, so that accented characters are always represented by a combined character or always by the character+combining mark.
Rough example:
String.metaClass.normalizeUnicode = {
return java.text.Normalizer.normalize(delegate, java.text.Normalizer.Form.NFC)
}
input = input.normalizeUnicode()
There are four forms of normalization. I picked the one that seems to be best for your case based on the description of how they work, but you may prefer to try the other ones and see what works most consistently.
All that being said, if you are try to representing Unicode characters in a URL, and they are not being loaded and processed by the code directly, it's probably best to avoid using non-latin characters altogether. Not only does this have the benefit of consistently, but also significantly shorter and more legible URLs. boo.pdf is a lot easier to read than bo%CC%88o.pdf.