Regex not matching? Encoding the issue? - php

Weird problem...
I have this document, when I copy the text and place it inside my script (as a string variable), the regex matches successfully. However, when I use file_get_contents to get to the document (from the internet), it does not.
Does this have something to do with encoding? The document is ISO-8859-1, but converted to utf8 via utf8_encode
Note that the string variable is created from this utf8 encoded output.
It's a simple regex too:
if (preg_match_all('/<h3 align=center><A NAME="([^"]*)"><\/A>(.*)<\/h3>(.*)::break::/isUu', $contents, $matches, PREG_SET_ORDER)) {
Any ideas what could be wrong?

This was not due to encoding, but due to the backtrack_limit being reached.
Overriding the setting with the following:
ini_set('pcre.backtrack_limit', '1000000');
(up from 100,000) fixes the issue. PHP 5.3.? also has this value so it's not just some really large number.

Related

Will comparing the binary data of a string with an unknown character encoding validate what its encoding is?

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.

PHP string encoding is not recognized by strpos()?

I have a binary Word .doc that looks something like this in string format:
þÿÿÿÿÿÿÿppp„±¶g œÙ Text in word doc here I'm interested in [|`ñÿ|Standard1$S_HmHnHsHtHOJPJQJCJEH567>
When I echo that string, I can see all the text I'm interested in finding in between unrecognized characters (but those I'm not worried about them since I only want the text). The issue is that PHP does not seem to recognize it as a string and so I cannot search it with strpos(), strpos(), strchr(), mb_strpos() all return nothing. No -1, no error in the PHP error log, just nothing.
However, when I call gettype() I get string. I suspect this is an encoding issue, but mb_detect_encoding returns UTF-8. I have tried converting it to multiple different encoding types, without avail.
How can I get PHP to search this string? I understand that parsing a Word .doc is more complex of an issue, but for my purposes the plaintext I'm interested in are in the binary data. Does anyone have any experience with this?
Thank you :)
Since you string seems binary encoded and you are only interested in text a quick solution would be to use filter_var to clean the string from non ascii-printable characters.Try using this before searching:
$clean_string = filter_var($str,FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH);
Notice the part "Standard1$". php is taking $ as the operator instead of a character.
check here.
<?php
$s = "þÿÿÿÿÿÿÿppp„±¶g œÙ Text in word doc here I'm interested in [|`ñÿ|Standard1$S_HmHnHsHtHOJPJQJCJEH567>";
$s2 = strpos($s, "interested");
echo $s2;
?>
you might want to put a backslash before that $ sign.

htmlspecialchars(): Invalid multibyte sequence in argument

I am getting this error in my local site.
Warning (2): htmlspecialchars(): Invalid multibyte sequence in argument in [/var/www/html/cake/basics.php, line 207]
Does anyone knows, what is the problem or what should be the solution for this?
Thanks.
Be sure to specify the encoding to UTF-8 if your files are encoded as such:
htmlspecialchars($str, ENT_COMPAT, 'UTF-8');
The default charset for htmlspecialchars is ISO-8859-1 (as of PHP v5.4 the default charset was turned to 'UTF-8'), which might explain why things go haywire when it meets multibyte characters.
I ran in to this error on production and found this great post about it -
http://insomanic.me.uk/post/191397106/php-htmlspecialchars-htmlentities-invalid
It appears to be a bug in PHP (for CentOS at least) that displays this error on when display errors is Off!
You are feeding corrupted character data into the function, or not specifying the right encoding.
I had this issue a while ago, old behavior (prior to PHP 5.2.7 I believe) was to return the string despite corruption, but since that version it will throw this error instead.
My solution involved writing a script to feed my strings through iconv using the //IGNORE modifier to remove corrupted data.
(We had a corrupted database which had some strings in UTF-8, some in latin-1 usually with incorrectly defined character types on the columns).
(Looking at the comment to Tatu's answer, I would start by looking at (and playing with) the contents of the $charset variable.
The correct code in order not to get any error is:
htmlentities($string, ENT_IGNORE, 'UTF-8') ;
Beside this you can also use str_replace to replace some bad characters to your needs and then use htmlentities function.
Have a look at this rss feed it replaced the greater html sign to gt; tag which might not look nice when reading thee rss feed. You can replace this with something like "-" sign or ")" and etc.
Had the same problem because I was using substr on utf-8 string.
Error was infrequent and seemingly random. Error occurred only if string was cut on multibyte char!
mb_substr solved the problem :)
That's actually one of the most frequent errors I get.
Sometimes I dont use __() translation - just plain German text containing äöü.
There it is especially important to mind the encoding of the files.
So make sure you properly save the files that contain special chars as UTF8.

html entities decoding in php

I seem to be completely unable to get around utf-8 character encoding.
So I'm exporting content from a database as a utf-8 xml file.
The software I am importing into is quite strict about character encoding, so I can't just put everything in CDATA tags.
There's a whole bunch of weird characters, e.g. ’, — … already in the data.
These aren't working in the xml and need to be replaced out (normally with just a ' quote).
Ideally, I'd like to decode all the characters, and then use htmlspecialchars($text, ENT_COMPAT, 'UTF-8', FALSE) to encode them back again. But I can't seem to find a function that will decode them. Is there one?
I've started to manually go through each entity with a str_replace() but it's turning into a much bigger job than I anticipated.
Any help would be a lifesaver.
Thanks
html_entity_decode() perhaps?
in some cases, in character conversion issues in php, it is important to have a locale set. Doesn't matter which, e.g.
setlocale(LC_CTYPE,'en_US.utf8');
But I would advise that any time invested in getting the encoding right from the beginning, without reverting to entities, if at all possible, is worth it.

Error: "Input is not proper UTF-8, indicate encoding !" using PHP's simplexml_load_string

I'm getting the error:
parser error : Input is not proper UTF-8, indicate encoding ! Bytes: 0xED 0x6E 0x2C 0x20
When trying to process an XML response using simplexml_load_string from a 3rd party source. The raw XML response does declare the content type:
<?xml version="1.0" encoding="UTF-8"?>
Yet it seems that the XML is not really UTF-8. The langauge of the XML content is Spanish and contain words like Dublín in the XML.
I'm unable to get the 3rd party to sort out their XML.
How can I pre-process the XML and fix the encoding incompatibilities?
Is there a way to detect the correct encoding for a XML file?
Your 0xED 0x6E 0x2C 0x20 bytes correspond to "ín, " in ISO-8859-1, so it looks like your content is in ISO-8859-1, not UTF-8. Tell your data provider about it and ask them to fix it, because if it doesn't work for you it probably doesn't work for other people either.
Now there are a few ways to work it around, which you should only use if you cannot load the XML normally. One of them would be to use utf8_encode(). The downside is that if that XML contains both valid UTF-8 and some ISO-8859-1 then the result will contain mojibake. Or you can try to convert the string from UTF-8 to UTF-8 using iconv() or mbstring, and hope they'll fix it for you. (they won't, but you can at least ignore the invalid characters so you can load your XML)
Or you can take the long, long road and validate/fix the sequences by yourself. That will take you a while depending on how familiar you are with UTF-8. Perhaps there are libraries out there that would do that, although I don't know any.
Either way, notify your data provider that they're sending invalid data so that they can fix it.
Here's a partial fix. It will definitely not fix everything, but will fix some of it. Hopefully enough for you to get by until your provider fix their stuff.
function fix_latin1_mangled_with_utf8_maybe_hopefully_most_of_the_time($str)
{
return preg_replace_callback('#[\\xA1-\\xFF](?![\\x80-\\xBF]{2,})#', 'utf8_encode_callback', $str);
}
function utf8_encode_callback($m)
{
return utf8_encode($m[0]);
}
I solved this using
$content = utf8_encode(file_get_contents('http://example.com/rss.xml'));
$xml = simplexml_load_string($content);
If you are sure that your xml is encoded in UTF-8 but contains bad characters, you can use this function to correct them :
$content = iconv('UTF-8', 'UTF-8//IGNORE', $content);
We recently ran into a similar issue and was unable to find anything obvious as the cause. There turned out to be a control character in our string but when we outputted that string to the browser that character was not visible unless we copied the text into an IDE.
We managed to solve our problem thanks to this post and this:
preg_replace('/[\x00-\x1F\x7F]/', '', $input);
Instead of using javascript, you can simply put this line of code after your mysql_connect sentence:
mysql_set_charset('utf8',$connection);
Cheers.
Can you open the 3rd party XML source in Firefox and see what it auto-detects as encoding? Maybe they are using plain old ISO-8859-1, UTF-16 or something else.
If they declare it to be UTF-8, though, and serve something else, their feed is clearly broken. Working around such a broken feed feels horrible to me (even though sometimes unavoidable, I know).
If it's a simple case like "UTF-8 versus ISO-8859-1", you can also try your luck with mb_detect_encoding().
If you download XML file and open it for example in Notepad++ you'll see that encoding is set to something else than UTF8 - I'v had the same problem with xml made myself, and it was just te encoding in the editor :)
String <?xml version="1.0" encoding="UTF-8"?> don't set up the encoding of the document, it's only info for validator or another resource.
I just had this problem. Turns out the XML file (not the contents) was not encoded in utf-8, but in ISO-8859-1. You can check this on a Mac with file -I xml_filename.
I used Sublime to change the file encoding to utf-8, and lxml imported it no issues.
After several tries i found htmlentities function works.
$value = htmlentities($value)
What I was facing was solved by what Erik proposed
https://stackoverflow.com/a/4575802/14934277
and it IS, actually, the only way to know if your data is okay to be printed.
And here is some peace of code that could be useful to anyone out there:
$product_desc = ..;
//Filter your $product_desc here. Remove tags, strip, do all you would do to print XML
try{(new SimpleXMLElement('<sth><![CDATA['.$product_desc.']]></sth>'))->asXML();}
catch(Exception $exc) {$product_desc = '';}; //Don't print trash
Note that part.
<![CDATA[]]>
When you try to create an XML out of it, be sure to pass it the final product a browser would see, meaning, having your field wrapped with CDATA
When generating mapping files using doctrine I ran into same issue. I fixed it by removing all comments that some fields had in the database.

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