I am trying to compare a value submitted as a POST to an internal string. They are both utf8 encoded. This is the code
echo $_POST["province"] . "\n";
setlocale(LC_COLLATE, "fr_CA");
echo strcoll($_POST["province"], "Québec");
This code echos the following:
Québec
-38
strcoll should return 0 if the string match, not -38. In other words, the comparison fails. How do I compare two utf8 string that are identical to a human reader, but might be encoded differently? I have tried Normalizer:normalize, the common "==" operator, looked at multibyte php extension (but there seem to be no compare functions??) and nothing worked thus far for me.
Make sure that you save your PHP files as UTF-8, it really matters.
Make sure that your HTML form actually sends UTF-8 data to the server.
If your PHP doesn't use UTF-8 as the internal encoding, you may have to use utf8_decode to ensure that the strings you're checking are in the same encoding.
Related
Everything in my code is running my database(Postgresql) is using utf8 encoding, I've checked the php.ini file its encoding is utf8, I tried debugging to see if it was any of the functions I used that were doing this, but nothing everything is running as expected, however after my frontend sends a post request to backend server through curl for some text to be inserted in the database, some characters like 'da' are converted to '?' in postgre and in memcached, I think php is converting them to Latin-1 again after the request reaches the other side for some reason becuase I use utf8_encode before the request and utf8_decode on the other side
this is the code to send the request
$pre_opp->
Send_Request_To_BackEnd("/Settings",$school_name,$uuid,"Upload_Bio","POST",str_replace(" ","%",utf8_encode($bio)));
this is how the backend system receives this
$data= str_replace("%"," ",utf8_decode($_POST["Data"]));
Don't replace " " with "%".
Use urlencode and urldecode instead of utf8_encode and utf8_decode - It will give you a clean alphanumeric representation of any character to easily transport your data.
If everything in your environment defaults to UTF-8, you shouldn't need utf_encode and utf_decode anyways, I guess. But if you still do, you could try combining both like this:
Send_Request_To_BackEnd("/Settings",$school_name,$uuid,"Upload_Bio","POST", urlencode(utf8_encode($bio)));
and
$data= str_replace("%"," ",utf8_decode(urldecode($_POST["Data"])));
You say this like it's a mystery:
I think php is converting them to Latin-1 again after the request reaches the other side for some reason
But then you give the reason yourself:
because I use utf8_encode before the request and utf8_decode on the other side
That is exactly what uf8_decode does: it converts UTF-8 to Latin-1.
As the manual explains, this is also where your '?' replacements come from:
This function converts the string string from the UTF-8 encoding to ISO-8859-1. Bytes in the string which are not valid UTF-8, and UTF-8 characters which do not exist in ISO-8859-1 (that is, characters above U+00FF) are replaced with ?.
Since you'd picked the unfortunate replacement of % for space, sequences like "%da" were being interpreted as URL percent escapes, and generating invalid UTF-8 strings. You then asked PHP to convert them to Latin-1, and it couldn't, so it substituted "?".
The simple solution is: don't do that. If your data is already in UTF-8, neither of those functions will do anything but mess it up; if it's not already in UTF-8, then work out what encoding it's in and use iconv or mb_convert_encoding to convert it, once. See also "UTF-8 all the way through".
Since we can't see your Send_Request_To_BackEnd function, it's hard to know why you thought you needed it. If you're constructing a URL with that string, you should use urlencode inside your request sending code; you shouldn't need to decode it the other end, PHP will do that for you.
During my work in updating some old projects im working through some old ANSI/ASCII files and encodings.
I want to have everything running utf-8 to make sure that i can support all kinds of languages.
I have a service where i send out sms'es using a microservice. I have an endpoint: /sms.php where i accept some parameters from _GET and these are then used in the application.
I have some test files where i make some requests to test if everything is ok.
My problem is that even though all files are utf8-encoded (i've checked multiple times)
My code looks like this:
$text = "message with æøå to make it utf8";
$params = urlencode($text);
$url = "http://localhost/sms.php?text=".$params;
echo mb_detect_encoding($text, "auto"); // this prints utf8
echo mb_detect_encoding($url, "auto"); // this prints ascii
$res = file_get_contents($url);
And this is also what i see in my receiving endpoint.
First i thought it was something to do with file_get_contents but since its being converted AFTER the urlencode it thought i might be it. But im not sure how to get around this problem.
The other problem i have is that a lot of my clients are using this old 2012 code (before i started using utf8 as standard) so i cant change the endpoint without causing them to make changes in their current setups.
In a comment i've been suggested to try to check for if the string is utf8 using
bin2hex:
bin2hex($_GET['text']); // 6d657373616765207769746820c3a6c3b8c3a520746f206d616b652069742075746638 which is inserted into the database: message with æøå to make it utf8
bin2hex(utf8_decode($_GET['text'])); // 6d657373616765207769746820e6f8e520746f206d616b652069742075746638 which is inserted into the database: message with æøå to make it utf8
Hope someone out there can point me in a correct direction.
I've looked into multiple stackoverflow entries for example
get utf8 urlencoded characters in another page using php
What's the correct encoding of HTTP get request strings?
but im not sure if what im looking for is even possible?
i was just hoping to be able to rewrite entire project to be utf8-ready
Thanks
/Wel
mb_detect_encoding gives you the first encoding in which the tested string is valid. If left to its own devices, it tests for ASCII before UTF-8. Since a URL-encoded string consists solely of a subset of ASCII characters, it is valid ASCII and mb_detect_encoding will tell you so. Whereas a string containing non-ASCII characters is not valid ASCII, so it will continue testing other encodings and eventually arrive at UTF-8.
UTF-8 is a superset of ASCII, so any string that is valid ASCII is also valid UTF-8. A string can be valid in multiple encodings at once; mb_detect_encoding telling you it's valid ASCII does not mean that it's not also valid UTF-8, or Latin-1, or numerous other encodings for that matter. That's how Mojibake is born.
Detecting encodings is largely vague nonsense anyway and you should never do that. If you expect a string to be in UTF-8, simply test whether it is valid UTF-8 or not:
mb_check_encoding($url, 'UTF-8')
If it's not valid in the expected encoding, discard it, since you have no clue what it really is then.
When I tested this little script:
$str = "apple";
echo md5($str);
The result matched the result of doing md5 using utf8 (tested using C#)
Should I trust that this will always be the case in any other environment?
If I where to put this script on any webhost, windows or linux, would it behave always the same with UTF8 encoding ?
The encoding of a string literal is whatever encoding you saved the source file in. If you saved this php file in UTF-16, you would get a different result, that is, if the code even runs.
There is no unified or managed encoding in PHP. Strings in PHP can be in any encoding, in other words, they are equivalent to byte arrays of languages that have more abstract string type.
Simply md5() will always give the same encoding.
If you cannot trust it, Simply you can encode data in Database itself.
PHP functions strlen() and mb_strlen() both are returning the wrong number of characters when I run them on a string.
Here is a piece of the code I'm using...
$foo = mb_strlen($itemDetails['ITEMDESC'], 'UTF-8');
echo $foo;
It is telling me this sting - "4½" Straight Iris Scissors" is 45 characters long. It's 27.
It also tells me that this string - "Infant Heel Warmer, No Adhesive Attachment Pad, 100/cs" is 54, which is correct.
I assume its some issue with character encoding, everything should be UTF-8 I think. I've tried feeding mb_strlen() several different character encoding types and they all are returning this oddball count with the string that has those non-standard characters.
I've no idea why this is happening.
Double-check whether your text really is UTF-8 or not. That "Â" character makes it look like a classic character encoding problem to me. You should check the entire path from the origin of the text through the point in your code that you quoted above, because there are a lot of places where the encodings can get munged.
Did the text originate from an HTML form? Ensure your <form> element includes the accept-charset="UTF-8" attribute.
Did the text get stored in a database along the way? Make sure the database stores and returns the data in UTF-8. This means checking the server's global defaults, the defaults for the database or schema, and the table itself.
It is very likely that your input is encoded in UTF-16.
You may convert to UTF-8
$foo = mb_strlen(mb_convert_encoding($itemDetails['ITEMDESC'], "UTF-8", "UTF-16"));
or if you use mb_strlen() be sure to use proper encoding as a second parameter.
$foo = mb_strlen($itemDetails['ITEMDESC'], "UTF-16");
Without correct encoding mb_strlen will always return wrong results. It's easy to get into troubles when you're dealing with UTF-8/16/32 encoded strings. mb_detect_encoding() will not solve this problem.
Supposed that im encoding my files with UTF-8.
Within PHP script, a string will be compared:
$string="ぁ";
$string = utf8_encode($string); //Do i need this step?
if(preg_match('/ぁ/u',$string))
//Do if match...
Its that string really UTF-8 without the utf8_encode() function?
If you encode your files with UTF-8 dont need this function?
If you read the manual entry for utf8_encode, it converts an ISO-8859-1 encoded string to UTF-8. The function name is a horrible misnomer, as it suggests some sort of automagic encoding that is necessary. That is not the case. If your source code is saved as UTF-8 and you assign "あ" to $string, then $string holds the character "あ" encoded in UTF-8. No further action is necessary. In fact, trying to convert the UTF-8 string (incorrectly) from ISO-8859-1 to UTF-8 will garble it.
To elaborate a little more, your source code is read as a byte sequence. PHP interprets the stuff that is important to it (all the keywords and operators and so on) in ASCII. UTF-8 is backwards compatible to ASCII. That means, all the "normal" ASCII characters are represented using the same byte in both ASCII and UTF-8. So a " is interpreted as a " by PHP regardless of whether it's supposed to be saved in ASCII or UTF-8. Anything between quotes, PHP simply takes as the literal bit sequence. So PHP sees your "あ" as "11100011 10000001 10000010". It doesn't care what exactly is between the quotes, it'll just use it as-is.
PHP does not care about string encoding generally, strings are binary data within PHP. So you must know the encoding of data inside the string if you need encoding. The question is: does encoding matter in your case?
If you set a string variables content to something like you did:
$string="ぁ";
It will not contain UTF-8. Instead it contains a binary sequence that is not a valid UTF-8 character. That's why the browser or editor displays a questionmark or similar. So before you go on, you already see that something might not be as intended. (Turned out it was a missing font on my end)
This also shows that your file in the editor is supporting UTF-8 or some other flavor of unicode encoding. Just keep the following in mind: One file - one encoding. If you store the string inside the file, it's in the encoding of that file. Check your editor in which encoding you save the file. Then you know the encoding of the string.
Let's just assume it is some valid UTF-8 like so (support for my font):
$string="ä";
You can then do a binary comparison of the string later on:
if ( 'ä' === $string )
# do your stuff
Because it's in the same file and PHP strings are binary data, this works with every encoding. So normally you don't need to re-encode (change the encoding) the data if you use functions that are binary safe - which means that the encoding of the data is not changed.
For regular expressions encoding does play a role. That's why there is the u modifier to signal you want to make the expression work on and with unicode encoded data. However, if the data is already unicode encoded, you don't need to change it into unicode before you use preg_match. However with your code example, regular expressions are not necessary at all and a simple string comparison does the job.
Summary:
$string="ä";
if ( 'ä' === $string )
# do your stuff
Your string is not a utf-8 character so it can't preg match it, hence why you need to utf8_encode it. Try encoding the PHP file as utf-8 (use something like Notepad++) and it may work without it.
Summary:
The utf8_encode() function will encode every byte from a given string to UTF-8.
No matter what encoding has been used previously to store the file.
It's purpose is encode strings¹ that arent UTF-8 yet.
1.- The correctly use of this function is giving as a parameter an ISO-8859-1 string.
Why? Because Unicode and ISO-8859-1 have the same characters at same positions.
[Char][Value/Position] [Encoded Value/Position]
[Windows-1252] [€][80] ----> [C2|80] Is this the UTF-8 encoded value/position of the [€]? No
[ISO-8859-1] [¢][A2] ----> [C2|A2] Is this the UTF-8 encoded value/position of the [¢]? Yes
The function seems that work with another encodings: it work if the string to encode contains only characters with same
values that the ISO-8859-1 encoding (e.g On Windows-1252 00-EF & A0-FF positions).
We should take into account that if the function receive an UTF-8 string (A file encoded as a UTF-8) will encode again that UTF-8 string and will make garbage.