PHP: Special Characters Conversion - php

I have this problem where I converted a special character to be put on the URL as a parameter using Javascript Ajax request and then reads it to PHP. The character is "Ñ".
In my javascript I put the parameter as escape('PiÑa') and is converted to "Pi%D1a"
And when I read it in my php a diamond shape with a question mark is what will appear. Here is how I read it.
escape(message) // Message being the "Pi%D1a"
Like I said a weird character comes out that when I save it my database, postgreSQL, It gives out an error. How do I fix this?

D1 is the ISO-8859-1 ("Latin-1") encoded form of the "Ñ" character.
A "diamond shape with a question mark" (�) is the Unicode Replacement Character. Whenever you see one, it indicates that the browser/editor/whatever-is-interpreting-the-text is trying to interpret text as Unicode and is encountering a character that is not valid in the assumed Unicode encoding.
In other words, the character is actually Latin-1 encoded but you're telling the browser it's (likely) UTF-8 encoded. You have an encoding mismatch. Either tell the browser the right encoding via a Content-Type: text/html; charset=XXX header, or convert the character from Latin-1 to UTF-8 before working with it.

Have you tried using urldecode($message)?
%D1 is the URL encoded representation of Ñ.

Related

UTF-8 encoding of UTF-8 encoded text is not the same as original UTF-8 encoded text

Here is a PHP code snippet I came up with when I found a bug in my project.
print(($str == utf8_encode($str) ? "the same text" : "not the same text") . PHP_EOL);
print(mb_detect_encoding($str));
Now what this does, is tell me if a string $str has the same encoding as its UTF-8 encoded version, after that it prints its initial encoding.
What I expected is that either the UTF-8 text is the same as the original, or that the original text is already UTF-8 and therefore the UTF-8 encoded text is the same as the original.
But what really happened is the following output:
not the same text
UTF-8
This is only the case if i set $str = array_keys($_POST)[0]; and i use a key with special characters in my request body like äöü=test so that the $str will be äöü (defining it directly in the code will not result in the same output).
I interpret from the output that the original character encoding is UTF-8, but the two strings are not the same. If I print the initial string it is empty and the encoded string would be äöü.
I don't understand how a string can be different when encoded with its own encoding. Can someone please explain this to me?
The problem is your assumption that "that the original text is already UTF-8 and therefore the UTF-8 encoded text is the same as the original".
From the PHP Official Documentation regarding utf8_encode (https://www.php.net/manual/en/function.utf8-encode.php):
This function converts the string data from the ISO-8859-1 encoding to UTF-8.
In other words, this function is a ISO-8859-1 to UTF-8 converter. A proper use of this function, as seen above, expects only a ISO-8859-1 string. Therefore, if you use another encoding as parameter you should expect garbage.
This thread (PHP: Convert any string to UTF-8 without knowing the original character set, or at least try) discuss an "any character enconding to UTF-8".
Hope it hepls

Decoding ISO-8859-1 and Encoding to UTF-8 before MySQL query

I'm kinda stuck if I'm doing it right.
I have a file which is ISO-8859-1 (pretty certain). My MySQL db is in utf-8 encoding. Which is why I want to convert the file to UTF-8 encoded characters before I can send it as a query. For instance, First I rewrite every line of the file.txt into file_new.txt using.
line = line.decode('ISO-8859-1').encode('utf-8')
And then I save it. Next, I create a MySQL connection and create a cursor with the following query so that all the data is received as utf-8.
query = 'SET NAMES "utf8"'
cursor.execute(query)
Following this, I reopen file_new.txt and enter each line into MySQL. Is this the right approach to get the table in MySQL utf-8 encoding? Or Am I missing any crucial part?
Now to receive this data. I use 'SET NAMES "utf8"" as well. But the received data is giving me question marks � when I set the header content type to
header("Content-Type: text/html; charset=utf-8");
On the other hand, when I set
header("Content-Type: text/html; charset=ISO-8859-1");
It works fine, but other utf-8 encoded data from the database is getting scrambled. So I'm guessing the data from file.txt is still NOT getting encoded to utf-8. Can any one explain why?
PS: Before I read everyline, I replace a character and save the file.txt to file.txt.tmp. I then read this file to get file_new.txt. I don't know if it causes any problem to the original file encoding.
f1 = codecs.open(tsvpath, 'rb',encoding='iso-8859-1')
f2 = codecs.open(tsvpath + '.tmp', 'wb',encoding='utf8')
for line in f1:
f2.write(line.replace('\"', '\''))
f1.close()
f2.close()
In the below example, I've utf-8 encoded persian data which is right but the other non-enlgish text is coming out to be in "question marks". This is precisely my problem.
Example : Removed.
Welcome to the wonderful world of unicode and windows. I've found this site very helpful in understanding what is going wrong with my strings http://www.i18nqa.com/debug/utf8-debug.html. The other thing you need is a hex editor like HxD. There are many places where things can go wrong. For example, if you are viewing your files in a text editor - it may be trying to be helpful and is silently changing your encoding.
Start with your original data, view it in HxD and see what the encoding is. View your results in Hxd and see if the changes you expect are being made. Repeat through the steps in your process.
Without your full code and sample data, its hard to say where the problem is. My guess is your replacing the double quote with single quote on binary files is the culprit.
Also check out The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)
by Joel Spolsky
Try this instead:
line = line.decode('ISO-8859-1').encode('utf-8-sig')
From the docs:
As UTF-8 is an 8-bit encoding no BOM is required and any U+FEFF
character in the decoded string (even if it’s the first character) is
treated as a ZERO WIDTH NO-BREAK SPACE.
Without external information it’s impossible to reliably determine
which encoding was used for encoding a string. Each charmap encoding
can decode any random byte sequence. However that’s not possible with
UTF-8, as UTF-8 byte sequences have a structure that doesn’t allow
arbitrary byte sequences. To increase the reliability with which a
UTF-8 encoding can be detected, Microsoft invented a variant of UTF-8
(that Python 2.5 calls "utf-8-sig") for its Notepad program: Before
any of the Unicode characters is written to the file, a UTF-8 encoded
BOM (which looks like this as a byte sequence: 0xef, 0xbb, 0xbf) is
written. As it’s rather improbable that any charmap encoded file
starts with these byte values (which would e.g. map to
LATIN SMALL LETTER I WITH DIAERESIS RIGHT-POINTING DOUBLE ANGLE
QUOTATION MARK INVERTED QUESTION MARK in iso-8859-1), this increases
the probability that a utf-8-sig encoding can be correctly guessed
from the byte sequence. So here the BOM is not used to be able to
determine the byte order used for generating the byte sequence, but as
a signature that helps in guessing the encoding. On encoding the
utf-8-sig codec will write 0xef, 0xbb, 0xbf as the first three bytes
to the file. On decoding utf-8-sig will skip those three bytes if they
appear as the first three bytes in the file. In UTF-8, the use of the
BOM is discouraged and should generally be avoided.
Source: https://docs.python.org/3.5/library/codecs.html
EDIT:
Sample:
"Hello World".encode('utf-8') yields b'Hello World' while "Hello World".encode('utf-8-sig') yields b'\xef\xbb\xbfHello World' highlighting the docs:
On encoding the
utf-8-sig codec will write 0xef, 0xbb, 0xbf as the first three bytes
to the file. On decoding utf-8-sig will skip those three bytes if they
appear as the first three bytes in the file.
Edit:
I have made a similar function before that converts a file to utf-8 encoding. Here is a snippet:
def convert_encoding(src, dst, unicode='utf-8-sig'):
return open(dst, 'w').write(open(src, 'rb').read().decode(unicode, 'ignore'))
Based on your example, try this:
convert_encoding('file.txt.tmp', 'file_new.txt')
Alright guys, so my encoding was right. The file was getting encoding to utf-8 just as needed. All the queries were right. It turns out that the other dataset that was in Arabic was in ISO-8859-1. Therefore, only 1 of them was working. No matter what I did.
The Hexeditors did help. But in the end I just used sublime text to recheck if my encoded data was utf-8. It turns out the python script and the sublime editor did the same. So the code is fine. :)
You should not need to do any explicit encode or decode. SET NAMES ... should match what the client encoding is (for INSERTing) or should become (for SELECTing).
MySQL will convert between the client encoding and the columns's CHARACTER SET.

php displays unicode escaped characters

The problem is age old: php + mysql + utf-8 encoding
We have a two component model: a backend service, that provides access to some json data via web-access and some client, that displays the data. the backend reads data from a mysql source, which is of collation type 'utf8 - default collation', the php script is utf-8 encoded.
The problem is that the rendered json data contains escaped unicode characters
like 'Rungestra\u00dfe 20'. what could be done to see the 'real' entity like 'ß' in this case?
The problem is that the rendered json data contains escaped unicode characters like 'Rungestra\u00dfe 20'
Why is that a problem? \u00DF is perfectly valid JSON syntax for the letter ß. Any JSON decoder will parse that string literal escape into the single character U+00DF Latin Small Letter Sharp S. For example if your client is a web browser then JSON.parse().
ß can be included in an HTML document as-is, you do not have to escape it to ß or ß.
Found this by google should help here.
https://stackoverflow.com/a/2577882/2422553
Try mb_convert_encoding() with the "to" encoding as 'HTML-ENTITIES', and (if necessary) the "from" encoding set to 'UTF-8' or whichever Unicode encoding you're using.

utf8_encode function purpose

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.

(PHP) rawurlencode/decode seems to encode '£' sign as '£' (%C2%A3 instead of %A3)

So, I've run into a problem with PHP's rawurlencode function. All text fields in our web app are of course converted before being processed by the web-server, and we've used rawurlencode for this. This works fine with almost every character I've found, expect for the "£" sign. Now, there is no reason for our users to ever enter a pound sign, but they might, so I want to take care of this.
The problem is that rawurlencode doesn't encode a pound sign entered on the webpage as %A3, but instead as %C2%A3. Even worse, if the user failed to enter another bit of critical information (which causes the webpage to refresh - the checks are done on the backend side - and try and refill the form boxes with the information the user had used), then when the %C2 is run through rawurldecode/encode, it becomes Ã? - aka, %C3?. And of course the "£" is also turned into another £!
So, what is causing this? I assume it's a character encoding issue, but I'm not that knowledgable about these things. I heard somewhere that I can encode £s as &pound manually, but why should I need to do that when the database can handle "£"s, and there is a percentage-encoding for a pound sign? Is this a bug in rawurlencode, or a bug caused by differing character sets?
Thanks for any help.
The standard requires forms to be submitted in the character encoding you specify in <form accept-charset="..."> or UTF-8 if it's not specified or the text the user has entered cannot be represented in the charset you specify.
Clearly, you're receiving the pound sign encoded in UTF-8. If you want to convert it to ISO-8859-15, write:
iconv("UTF-8", "ISO-8859-15//TRANSLIT", $original)
This is probably encoding A3 character in your native character set to C2A3 in UTF-8 encoding, which seems to be the valid UTF-8 encoding for an ANSI A3. Just consume your encoded url using UTF-8 encoding, or specify an ANSI encoding to urlencode.
Artefacto's answer represents a case when you need to convert character encodings, for example, you are displaying a page and the page encoding is set to Latin-1. (Raw)Urlencode will produce escaped strings with multibyte character representations. (Raw)Urldecode will by default produce utf-8 encoded strings, and will represent £ as two bytes. If you display this string making a claim that it is a ISO-8859 encoded string, it will appear as two characters.
A primer on PHP and UTF-8: http://www.phpwact.org/php/i18n/utf-8
Some "hot tips": http://www.sitepoint.com/blogs/2006/08/10/hot-php-utf-8-tips/
Likely, between getting the string from rawurldecode, and using the string, the locale is assumed to be ISO8859, so two bytes get interpreted as two characters when they represent one.
Use mb_convert_encoding to force PHP to realize that the bytes in the string represent a UTF-8 encoded string.

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