I have an XML with special Characters encoded as &#xxx; in it. As long as I'd output these characters to a browser, that would work fine as they're HTML-Encodings (sort of).
But I need to read the XML-File with simplexml_load_string, which results in garbage for certain characters, because they're in the extended ASCII-table.
For example:
translates to š - but when I try to use html_entity_decode, I get an empty character.
I tried almost everything from iconv to mb_decode_numericentity - nothing worked.
How do I convert those &#xxx; to the real characters???
[Edit]
I found this table http://www.ascii-code.com that claims the is an extended ASCII Character using ISO-8859-1
I'm confused...
You're apparently dealing with two different characters that look almost identical when printing:
'LATIN SMALL LETTER S WITH CARON' (U+0161) actually encodes as š
corresponds to 'SINGLE CHARACTER INTRODUCER' (U+009A)
I've found that none of my fonts or text editors handle the second one properly. So you most likely get a blank character for that precise reason.
The second one appears to be some kind of weird control character whose exact purpose escapes from my understanding:
To be followed by a single printable character (0x20 through 0x7E) or
format effector (0x08 through 0x0D). The intent was to provide a means
by which a control function or a graphic character that would be
available regardless of which graphic or control sets were in use
could be defined. Definitions of what the following byte would invoke
was never implemented in an international standard. Not part of the
first edition of ISO/IEC 6429
It's worth noting that character references in XML use numeric codes from a fixed encoding (some UCS variant). If the author of the XML file doesn't follow this convention you'll be faced with either invalid XML (something that effectively prevents it from being parsed with an XML library) or valid XML that contains corrupted data (something that, at most, will require tedious post-processing).
Related
I need to automatically determine the character encoding of strings from email content and headers. For the most part this isn't an issue however there is an occasional email with content and/or a header that has an oddball character such as an en dash. Now I received an answer that technically seems to work if I statically test it on a specific header for a specific email however that blatantly ignores the fact that importing email needs to be a completely automated process in which case I am utterly unable to automatically determine the string's character encoding.
I've started with the basics such as detecting common trouble characters that seem to guarantee a character encoding issue will occur. However strpos('en dash: –', '–') works fine while intentionally / manually testing though it fails outright when added directly to the automated process. I'm going to guess that the issue there is that the string parameters have a UTF-8 encoding while the automated process is testing a string that isn't yet UTF-8 and thus internally the same character isn't using the same subset of code (via character encoding).
So my second attempt was mb_detect_encoding's second parameter can be an array. So I tried the following:
$encodings = array('UTF-8','UCS-4','UCS-4BE','UCS-4LE','UCS-2','UCS-2BE','UCS-2LE','UTF-32','UTF-32BE','UTF-32LE','UTF-16','UTF-16BE','UTF-16LE','UTF-7','UTF7-IMAP','ASCII','EUC-JP','SJIS','eucJP-win','SJIS-win','ISO-2022-JP','ISO-2022-JP-MS','CP932','CP51932','SJIS-mac','SJIS-Mobile#DOCOMO','SJIS-Mobile#KDDI','SJIS-Mobile#SOFTBANK','UTF-8-Mobile#DOCOMO','UTF-8-Mobile#KDDI-A','UTF-8-Mobile#KDDI-B','UTF-8-Mobile#SOFTBANK','ISO-2022-JP-MOBILE#KDDI','JIS','JIS-ms','CP50220','CP50220raw','CP50221','CP50222','ISO-8859-1','ISO-8859-2','ISO-8859-3','ISO-8859-4','ISO-8859-5','ISO-8859-6','ISO-8859-7','ISO-8859-8','ISO-8859-9','ISO-8859-10','ISO-8859-13','ISO-8859-14','ISO-8859-15','ISO-8859-16','byte2be','byte2le','byte4be','byte4le','BASE64','HTML-ENTITIES','7bit','8bit','EUC-CN','CP936','GB18030','HZ','EUC-TW','CP950','BIG-5','EUC-KR','UHC','ISO-2022-KR','Windows-1251','Windows-1252','CP866','KOI8-R','KOI8-U','ArmSCII-8');
$encoding = mb_detect_encoding($s, $encodings, true);
$compare = mb_convert_encoding($s, 'UTF-8', $encoding);
foreach ($encodings as $k1)
{
if (mb_convert_encoding($s, 'UTF-8', $k1) === $s) {$encoding = $k1; break;}
}
Unfortunately that seemed to result in the same failure based on what I presume was the same underlying issue.
So my third idea I'm looking for some more experienced validation. I could convert the string down in its binary form (ones and zeroes, not binary data). Then I could try converting the string and then converting that second string to binary to compare the two binary versions; if they === match then I might have determined the correct character encoding?
Now I can easily try this with this answer from an unrelated thread however I'm not certain if this is a valid idea or not. This is all intended to answer my question:
How can I determine the actual character encoding of a string in order to convert it to UTF-8 with fully automated validation without corrupting data?
By validation I'm talking about stuff like comparing the binary data though again, I'm not certain if that is a valid approach or not. I do know that I absolutely hate en dashes though.
The answer won't change: it's impossible. You have to rely on external information which encoding is used on text.
Guessing an encoding can horribly go wrong:
Based on the order in which you test against it can either turn out as i.e. ASCII or UTF-8 or Windows-1252, just because so far it fits in. Your list is questionable, because it may match Base64 which is not even a text encoding.
If the source is not properly encoded itself then guessing its encoding will most likely exclude the correct one. And guess a wrong one. Which makes things worse.
Many encodings share the same area: the source can either fit i.e. Windows-1252 or Windows-1251 and even detecting the lexical sense of the text cannot guarantee which of both is correct.
Also: ones and zeroes are binary. PHP strings are only byte arrays, so they're binary to begin with. How they're interpreted relies on you: if your code is $text= "グリーン"; then it's up to which encoding your PHP text file has and how your PHP defaults are set. There is no "internal ... character", only bytes. Which is also the reason why there are functions which operate on bytes (i.e. strlen()) and on a specific text encoding (i.e. mb_strlen()).
If you hate single characters or not: they can be easily used as what they are: characters in texts. And – has its own valid meaning in contrast to — and ‒ and -; don't replace it by personal opinion, because that could corrupt a context's meaning. It's like ignoring the fact that A and Α and A are all different characters. You might want to look up the difference between homoglyphs and synoglyphs - the latter is your current perspective.
You may ask "And in which encoding does PHP interpret the scripts?" Luckily ASCII is for most encodings the most common denominator, so interpreting the first bytes of a file as such to search for <?php (all these are ASCII characters, so for PHP code itself it doesn't matter if it is effectively UTF-8 or ISO-8859-1 or Shift-JIS) will only fail when the document is encoded in i.e. UTF-16 - in that case you must set your PHP defaults to that encoding. Which again proves: text encodings must be told outside of the text.
I received a string with an unknown character encoding via import. How can I display such a string in the browser so that it can be reproduced as PHP code?
I would like to illustrate the problem with an example.
$stringUTF8 = "The price is 15 €";
$stringWin1252 = mb_convert_encoding($stringUTF8,'CP1252');
var_dump($stringWin1252); //string(17) "The price is 15 �"
var_export($stringWin1252); // 'The price is 15 �'
The string delivered with var_export does not match the original. All unrecognized characters are replaced by the � symbol. The string is only generated here with mb_convert_encoding for test purposes. Here the character coding is known. In practice, it comes from imports e.G. with file_cet_contents() and the character coding is unknown.
The output with an improved var_export that I expect looks like this:
"The price is 15 \x80"
My approach to the solution is to find all non-UTF8 characters and then show them in hexadecimal. The code for this is too extensive to be shown here.
Another variant is to output all characters in hexadecimal PHP notation.
function strToHex2($str) {
return '\x'.rtrim(chunk_split(strtoupper(bin2hex($str)),2,'\x'),'\x');
}
echo strToHex2($stringWin1252);
Output:
\x54\x68\x65\x20\x70\x72\x69\x63\x65\x20\x69\x73\x20\x31\x35\x20\x80
This variant is well suited for purely binary data, but quite large and difficult to read for general texts.
My question in other words:
How can I change all non-UTF8 characters from a string to the PHP hex representation "\xnn" and leave correct UTF8 characters.
I'm going to start with the question itself:
How can I reproducibly represent a non-UTF8 string in PHP (Browser)
The answer is very simple, just send the correct encoding in an HTML tag or HTTP header.
But that wasn't really your question. I'm actually not 100% sure what the true question is, but I'm going to try to follow what you wrote.
I received a string with an unknown character encoding via import.
That's really where we need to start. If you have an unknown string, then you really just have binary data. If you can't determine what those bytes represents, I wouldn't expect the browser or anyone else to figure it out either. If you can, however, determine what those bytes represent, then once again, send the correct encoding to the client.
How can I display such a string in the browser so that it can be reproduced
as PHP code?
You are round-tripping here which is asking for problems. The only safe and sane answer is Unicode with one of the officially support encodings such as UTF-8, UTF-16, etc.
The string delivered with var_export does not match the original. All unrecognized characters are replaced by the � symbol.
The string you entered as a sample did not end with a byte sequence of x80. Instead, you entered the € character which is 20AC in Unicode and expressed as the three bytes xE2 x82 xAC in UTF-8. The function mb_convert_encoding doesn't have a map of all logical characters in every encoding, and so for this specific case it doesn't know how to map "Euro Sign" to the CP1252 codepage. Whenever a character conversion fails, the Unicode FFFD character is used instead.
The string is only generated here with mb_convert_encoding for test purposes.
Even if this is just for testing purposes, it is still messing with the data, and the previous paragraph is important to understand.
Here the character coding is known. In practice, it comes from imports e.g. with file_get_contents() and the character coding is unknown.
We're back to arbitrary bytes at this point. You can either have PHP guess, or if you have a corpus of known data you could build some heuristics.
The output with an improved var_export that I expect looks like this:
"The price is 15 \x80"
Both var_dump and var_export are intended to show you quite literally what is inside the variable, and changing them would have a giant BC problem. (There actually was an RFC for making a new dumping function but I don't think it did what you want.)
In PHP, strings are just byte arrays so calling these functions dumps those byte arrays to the stream, and your browser or console or whatever takes the current encoding and tries to match those bytes to the current font. If your font doesn't support it, one of the replacement characters is shown. (Or, sometimes a device tries to guess what those bytes represent which is why you see € or similar.) To say that again, your browser/console does this, PHP is not doing that.
My approach to the solution is to find all non-UTF8 characters
That's probably not what you want. First, it assumes that the characters are UTF-8, which you said was not an assumption that you can make. Second, if a file actually has byte sequences that aren't valid UTF-8, you probably have a broken file.
How can I change all non-UTF8 characters from a string to the PHP hex representation "\xnn" and leave correct UTF8 characters.
The real solution is to use Unicode all the way through your application and to enforce an encoding whenever you store/output something. This also means that when viewing this data that you have a font capable of showing those code points.
When you ingest data, you need to get it to this sane point first, and that's not always easy. Once you are Unicode, however, you should (mostly) be safe. (For "mostly", I'm looking at you Emojis!)
But how do you convert? That's the hard part. This answer shows how to manually convert CP1252 to UTF-8. Basically, repeat with each code point that you want to support.
If you don't want to do that, and you really want to have the escape sequences, then I think I'd inspect the string byte by byte, and anything over x7F gets escaped:
$s = "The price is 15 \x80";
$buf = '';
foreach(str_split($s) as $c){
$buf .= $c >= "\x80" ? '\x' . bin2hex($c) : $c;
}
var_dump($buf);
// string(20) "The price is 15 \x80"
I got a big sitemap created dynamically with PHP, it has a sitemap index with some 230 separate sitemaps, and each individual sitemap has between 3.000 and 15.000 URLs.
In most of those 230 sitemaps, everything is ok, but in some of them some URLs contain special characters and Google returns an error, does not accept such sitemap. The example of a normal, accepted URL:
http://www.site.com/Gentofte-Greve/Denmark 1 Badmintonligaen/12-fe-juice_a-1091627-1-33-1-odds/
The example of an URL which corrupts the entire sitemap file for Google:
http://www.site.com/Team%20%C5rhus%20Elite-Solr%F8d%20Strand/Denmark 1 Badmintonligaen/12-fe-juice_a-1091631-1-33-1-odds/
Any special character, for example the Nordic ones, will wreck the sitemap. Here is an example of Nordic characters: http://www.borgos.nndata.no/alfabet.htm
My questions is - HOW do I code those special characters (and other similar ones) so sitemap still checks out fine. Which PHP coding function do I use if that's a solution? Is the only solution to use str_replace and replace those characters with normal ones? It wouldn't be an issue, the URL works no matter what you write in the first part of it as that part is for SEO only, but this would be time-consuming. I'd prefer to be able to write those special characters in a way which doesn't wreck the sitemap for Google.
Everything else regarding my sitemaps is fine, they're coded in UTF-8 or at least they should be with this line:
<?xml version='1.0' encoding='UTF-8'?>
Are the %C5 and %F8 sequences meant to represent the characters U+00C5 (Å) and U+00F8 (ø)? If so, you need to use their UTF-8 encodings, not their raw Unicode codepoint numbers. 'Å' should be %C3%85, and 'ø' should be %C3%B8.
For more information about URI encoding, see RFC 3986.
Doing this in PHP is complicated by the fact that PHP strings are really byte strings, not Unicode character strings. They can't store abstract Unicode characters; they can only store the encoded representation of those characters, in a particular encoding such as UTF-8 or UTF-16. You can use the mbstring extension to work with encoded Unicode strings, but doing this correctly will probably mean using the mbstring functions for all handling of Unicode text throughout your application.
You should be looking to fix this encoding problem at the source: how did your program get a string that contains the byte 0xC5 to represent the character U+00C5? Something, somewhere, must've assumed that Unicode codepoint numbers translate directly into bytes, which is wrong. Find and fix that, so that your data is read into the PHP string in UTF-8 form to begin with, and then use the mbstring functions for any manipulation of the string afterward.
Once you have a string that contains the UTF-8 representation of your URL, rawurlencode() should give you the correct percent-escaped result.
I'm making a cURL request to a third party website which returns a text file on which I need to do a few string replacements to replace certain characters by their html entity equivalents e.g I need to replace í by í.
Using string_replace/preg_replace_callback on the response directly didn't result in matches (whether searching for í directly or using its hex code \x00\xED), so I used utf8_encode() before carrying out the replacement. But utf8_encode replaces all the í characters by Ã.
Why is this happening, and what's the correct approach to carrying out UTF-8 replacements on an arbitrary piece of text using php?
*edit - some further research reveals
utf8_decode("í") == í;
utf8_encode("í") == ÃÂ;
utf8_encode("\xc3\xad") == ÃÂ;
utf8_encode is definitely not the way to go here (you're double-encoding if you do that).
Re. searching for the character directly or using its hex code, did you make sure to add the u modifier at the end of the regex? e.g. /\x00\xED/u?
You're probably specify the characters/strings you want replaced via string literals in the php source code? If you do, then the values of those string literals depends on the encoding you save your php file in. So while you see the character í, maybe the literal value is a latin encoded í, like maybe 8859-1 encoding, or maybe its windows cp1252 í, or maybe its utf8 í, or maybe even utf32 í...i dont know off hand how many of those are different, but i know at least some have different byte representations, and so wont match in a php string comparison.
my point is, you need to specify the correct character that will match whatever encoding your incoming text is in.
heres an example without using literals
$iso8859_1 = chr(236);
$utf8 = utf8_encode(chr(236));
be warned, text editors may or may not convert the existing characters when you change the encoding, if you decide to change the file encoding to utf8. I've seen editors do really bizarre things when changing the encoding. Start with a fresh file.
also-just because the other server claims its utf8, doesn't mean it really is.
I'm trying to make a URL-safe version of a string.
In my database I have a value medúlla - I want to turn this into medulla.
I've found plenty of functions to do this, but when I retrieve the value from the database it comes back as medúlla.
I've tried:
Setting the column as utf_8 encoding
Setting the table as utf_8 encoding
Setting the entire database as utf_8 encoding
Running `SET NAMES utf8` on the database before querying
When I echo the value onto the screen it displays as I want it to, but the conversion function doesn't see the ú character (even a simple str_replace() doesn't work either).
Does anybody know how I can force the system to recognise this as UTF-8 and allow me to run the conversion?
Thanks,
Matt
To transform an UTF-8 string into an URL-safe string you should use:
$str = iconv('UTF-8', 'ASCII//IGNORE//TRANSLIT', $strt);
The IGNORE part tells iconv() not to raise an exception when facing a character it can't manage, and the TRANSLIT part converts an UTF-8 character into its nearest ASCII equivalent ('ú' into 'u' and such).
Next step is to preg_replace() spaces into underscores and substitute or drop any character which is unsafe within an URL, either with preg_replace() or urlencode().
As for the database stuff, you really should have done all this setting stuff before INSERTing UTF-8 content. Changing charset to an existing table is somewhat like changing a file extension in Windows - it doesn't convert a JPEG into a GIF. But don't worry and remember that the database will return you byte by byte exactly what you've stored in it, no matter which charset has been declared. Just keep the settings you used when INSERTing and treat the returned strings as UTF-8.
I'm trying to make a URL-safe version of a string.
Whilst it is common to use ASCII-only ‘slugs’ in URLs, it is actually possible to have web addresses including non-ASCII characters. eg.:
http://en.wikipedia.org/wiki/Medúlla
This is a valid IRI. For inclusion in a URI, you should UTF-8 and %-encode it:
http://en.wikipedia.org/wiki/Med%C3%BAlla
Either way, most browsers (except sometimes not IE) will display the IRI version in the address bar. Sites such as Wikipedia use this to get pretty addresses.
the conversion function doesn't see the ú character
What conversion function? rawurlencode() will correctly spit out %C3%BA for ú, if, as presumably you do, you have it in UTF-8 encoding. This is the correct way to include text in a URL's path component. (urlencode() also gives the same results, but it should only be used for query components.)
If you mean htmlentities()... do not use this function. It converts all non-ASCII characters to HTML character references, which makes your output unnecessarily larger, and means it has to know what encoding the string you pass in is. Unless you give it a UTF-8 $charset argument it will use ISO-8859-1, and consequently screw up all your non-ASCII characters.
Unless you are specifically authoring for an environment which mangles non-ASCII characters, it is better to use htmlspecialchars(). This gives smaller output, and it doesn't matter(*) if you forget to include the $charset argument, since all it changes is a couple of characters like < and &.
(Actually it could matter for some East Asian multibyte character sets where < could be part of a multibyte sequence and so shouldn't be escaped. But in general you'd want to avoid these legacy encodings, as UTF-8 is less horrific.)
(even a simple str_replace() doesn't work either).
If you wrote str_replace(..., 'ú', ...) in the PHP source code, you would have to be sure that you saved the source code in the same encoding as you'll be handling, otherwise it won't match.
It is unfortunate that most Windows text editors still save in the (misleadingly-named) “ANSI” code page, which is locale-specific, instead of just using UTF-8. But it should be possible to save the file as UTF-8, and then the replace should work. Alternatively, write '\xc3\xba' to avoid the problem.
Running SET NAMES utf8 on the database before querying
Use mysql_set_charset() in preference.