I'm writing an API that creates text files.
It's used by legacy software that requires the files to be with the Windows 1255 encoding.
I'm creating the content of the file from a good old JavaScript string.
This is the relevant parts of the code I have so far:
var iconv = require('iconv-lite');
const str = 'Hello world, שלום עולם';
const encoded_str = iconv.encode(str, 'win1255', {addBOM: true});
response.status(200).send('data:text/plain;base64,' + Buffer.from(str, 'binary').toString('base64'));
It sends a text file successfully. Its ASCII content is preserved and is shown nicely when I open it in notepad, but any non-ASCII (think: Hebrew) characters are garbled.
I have a gut feeling it has something to do with the base64 conversion.
(the file is later opened using an HTML <a href="..."> tag)
Your code is correct.
The reason you're seeing garbled characters has more to do with your Windows settings.
Windows-1255 is an old standard. These days we use UTF (Unicode).
Windows-1255, like other Windows code pages, is 8-bit SBCS.
The first 127 values are ASCII compatible. The other ones take a different meaning based on encoding. Hebrew encodings give them Hebrew meanings, Japaneese give them Japaneese meanings, etc...
There aren't enough bits to represent the wide variety of symbols.
If you go to your Windows settings and define how to treat non-unicode encodings, it will change which meanings the upper 127 numbers take.
Go and set it to Hebrew, and your content won't be garbled anymore.
Further reading: Joel on Software - The absolute minimum every software developer absolutely positively must know about unicode and character sets, no excuses.
I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.
Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?
This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.
Data Storage:
Specify the utf8mb4 character set on all tables and text columns in your database. This makes MySQL physically store and retrieve values encoded natively in UTF-8. Note that MySQL will implicitly use utf8mb4 encoding if a utf8mb4_* collation is specified (without any explicit character set).
In older versions of MySQL (< 5.5.3), you'll unfortunately be forced to use simply utf8, which only supports a subset of Unicode characters. I wish I were kidding.
Data Access:
In your application code (e.g. PHP), in whatever DB access method you use, you'll need to set the connection charset to utf8mb4. This way, MySQL does no conversion from its native UTF-8 when it hands data off to your application and vice versa.
Some drivers provide their own mechanism for configuring the connection character set, which both updates its own internal state and informs MySQL of the encoding to be used on the connection—this is usually the preferred approach. In PHP:
If you're using the PDO abstraction layer with PHP ≥ 5.3.6, you can specify charset in the DSN:
$dbh = new PDO('mysql:charset=utf8mb4');
If you're using mysqli, you can call set_charset():
$mysqli->set_charset('utf8mb4'); // object oriented style
mysqli_set_charset($link, 'utf8mb4'); // procedural style
If you're stuck with plain mysql but happen to be running PHP ≥ 5.2.3, you can call mysql_set_charset.
If the driver does not provide its own mechanism for setting the connection character set, you may have to issue a query to tell MySQL how your application expects data on the connection to be encoded: SET NAMES 'utf8mb4'.
The same consideration regarding utf8mb4/utf8 applies as above.
Output:
UTF-8 should be set in the HTTP header, such as Content-Type: text/html; charset=utf-8. You can achieve that either by setting default_charset in php.ini (preferred), or manually using header() function.
If your application transmits text to other systems, they will also need to be informed of the character encoding. With web applications, the browser must be informed of the encoding in which data is sent (through HTTP response headers or HTML metadata).
When encoding the output using json_encode(), add JSON_UNESCAPED_UNICODE as a second parameter.
Input:
Browsers will submit data in the character set specified for the document, hence nothing particular has to be done on the input.
In case you have doubts about request encoding (in case it could be tampered with), you may verify every received string as being valid UTF-8 before you try to store it or use it anywhere. PHP's mb_check_encoding() does the trick, but you have to use it religiously. There's really no way around this, as malicious clients can submit data in whatever encoding they want, and I haven't found a trick to get PHP to do this for you reliably.
Other Code Considerations:
Obviously enough, all files you'll be serving (PHP, HTML, JavaScript, etc.) should be encoded in valid UTF-8.
You need to make sure that every time you process a UTF-8 string, you do so safely. This is, unfortunately, the hard part. You'll probably want to make extensive use of PHP's mbstring extension.
PHP's built-in string operations are not by default UTF-8 safe. There are some things you can safely do with normal PHP string operations (like concatenation), but for most things you should use the equivalent mbstring function.
To know what you're doing (read: not mess it up), you really need to know UTF-8 and how it works on the lowest possible level. Check out any of the links from utf8.com for some good resources to learn everything you need to know.
I'd like to add one thing to chazomaticus' excellent answer:
Don't forget the META tag either (like this, or the HTML4 or XHTML version of it):
<meta charset="utf-8">
That seems trivial, but IE7 has given me problems with that before.
I was doing everything right; the database, database connection and Content-Type HTTP header were all set to UTF-8, and it worked fine in all other browsers, but Internet Explorer still insisted on using the "Western European" encoding.
It turned out the page was missing the META tag. Adding that solved the problem.
Edit:
The W3C actually has a rather large section dedicated to I18N. They have a number of articles related to this issue – describing the HTTP, (X)HTML and CSS side of things:
FAQ: Changing (X)HTML page encoding to UTF-8
Declaring character encodings in HTML
Tutorial: Character sets & encodings in XHTML, HTML and CSS
Setting the HTTP charset parameter
They recommend using both the HTTP header and HTML meta tag (or XML declaration in case of XHTML served as XML).
In addition to setting default_charset in php.ini, you can send the correct charset using header() from within your code, before any output:
header('Content-Type: text/html; charset=utf-8');
Working with Unicode in PHP is easy as long as you realize that most of the string functions don't work with Unicode, and some might mangle strings completely. PHP considers "characters" to be 1 byte long. Sometimes this is okay (for example, explode() only looks for a byte sequence and uses it as a separator -- so it doesn't matter what actual characters you look for). But other times, when the function is actually designed to work on characters, PHP has no idea that your text has multi-byte characters that are found with Unicode.
A good library to check into is phputf8. This rewrites all of the "bad" functions so you can safely work on UTF8 strings. There are extensions like the mb_string extension that try to do this for you, too, but I prefer using the library because it's more portable (but I write mass-market products, so that's important for me). But phputf8 can use mb_string behind the scenes, anyway, to increase performance.
Warning: This answer applies to PHP 5.3.5 and lower. Do not use it for PHP version 5.3.6 (released in March 2011) or later.
Compare with Palec's answer to PDO + MySQL and broken UTF-8 encoding.
I found an issue with someone using PDO and the answer was to use this for the PDO connection string:
$pdo = new PDO(
'mysql:host=mysql.example.com;dbname=example_db',
"username",
"password",
array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));
In my case, I was using mb_split, which uses regular expressions. Therefore I also had to manually make sure the regular expression encoding was UTF-8 by doing mb_regex_encoding('UTF-8');
As a side note, I also discovered by running mb_internal_encoding() that the internal encoding wasn't UTF-8, and I changed that by running mb_internal_encoding("UTF-8");.
First of all, if you are in PHP before 5.3 then no. You've got a ton of problems to tackle.
I am surprised that none has mentioned the intl library, the one that has good support for Unicode, graphemes, string operations, localisation and many more, see below.
I will quote some information about Unicode support in PHP by Elizabeth Smith's slides at PHPBenelux'14
INTL
Good:
Wrapper around ICU library
Standardised locales, set locale per script
Number formatting
Currency formatting
Message formatting (replaces gettext)
Calendars, dates, time zone and time
Transliterator
Spoofchecker
Resource bundles
Convertors
IDN support
Graphemes
Collation
Iterators
Bad:
Does not support zend_multibyte
Does not support HTTP input output conversion
Does not support function overloading
mb_string
Enables zend_multibyte support
Supports transparent HTTP in/out encoding
Provides some wrappers for functionality such as strtoupper
ICONV
Primary for charset conversion
Output buffer handler
mime encoding functionality
conversion
some string helpers (len, substr, strpos, strrpos)
Stream Filter stream_filter_append($fp, 'convert.iconv.ISO-2022-JP/EUC-JP')
DATABASES
MySQL: Charset and collation on tables and on the connection (not the collation). Also, don't use mysql - mysqli or PDO
postgresql: pg_set_client_encoding
sqlite(3): Make sure it was compiled with Unicode and intl support
Some other gotchas
You cannot use Unicode filenames with PHP and windows unless you use a 3rd part extension.
Send everything in ASCII if you are using exec, proc_open and other command line calls
Plain text is not plain text, files have encodings
You can convert files on the fly with the iconv filter
The only thing I would add to these amazing answers is to emphasize on saving your files in UTF-8 encoding, I have noticed that browsers accept this property over setting UTF-8 as your code encoding. Any decent text editor will show you this. For example, Notepad++ has a menu option for file encoding, and it shows you the current encoding and enables you to change it. For all my PHP files I use UTF-8 without a BOM.
Sometime ago I had someone ask me to add UTF-8 support for a PHP and MySQL application designed by someone else. I noticed that all files were encoded in ANSI, so I had to use iconv to convert all files, change the database tables to use the UTF-8 character set and utf8_general_ci collate, add 'SET NAMES utf8' to the database abstraction layer after the connection (if using 5.3.6 or earlier. Otherwise, you have to use charset=utf8 in the connection string) and change string functions to use the PHP multibyte string functions equivalent.
I recently discovered that using strtolower() can cause issues where the data is truncated after a special character.
The solution was to use
mb_strtolower($string, 'UTF-8');
mb_ uses MultiByte. It supports more characters but in general is a little slower.
In PHP, you'll need to either use the multibyte functions, or turn on mbstring.func_overload. That way things like strlen will work if you have characters that take more than one byte.
You'll also need to identify the character set of your responses. You can either use AddDefaultCharset, as above, or write PHP code that returns the header. (Or you can add a META tag to your HTML documents.)
I have just gone through the same issue and found a good solution at PHP manuals.
I changed all my files' encoding to UTF8 and then the default encoding on my connection. This solved all the problems.
if (!$mysqli->set_charset("utf8")) {
printf("Error loading character set utf8: %s\n", $mysqli->error);
} else {
printf("Current character set: %s\n", $mysqli->character_set_name());
}
View Source
Unicode support in PHP is still a huge mess. While it's capable of converting an ISO 8859 string (which it uses internally) to UTF-8, it lacks the capability to work with Unicode strings natively, which means all the string processing functions will mangle and corrupt your strings.
So you have to either use a separate library for proper UTF-8 support, or rewrite all the string handling functions yourself.
The easy part is just specifying the charset in HTTP headers and in the database and such, but none of that matters if your PHP code doesn't output valid UTF-8. That's the hard part, and PHP gives you virtually no help there. (I think PHP 6 is supposed to fix the worst of this, but that's still a while away.)
If you want a MySQL server to decide the character set, and not PHP as a client (old behaviour; preferred, in my opinion), try adding skip-character-set-client-handshake to your my.cnf, under [mysqld], and restart mysql.
This may cause trouble in case you're using anything other than UTF-8.
The top answer is excellent. Here is what I had to on a regular Debian, PHP, and MySQL setup:
// Storage
// Debian. Apparently already UTF-8
// Retrieval
// The MySQL database was stored in UTF-8,
// but apparently PHP was requesting ISO 8859-1. This worked:
// ***notice "utf8", without dash, this is a MySQL encoding***
mysql_set_charset('utf8');
// Delivery
// File *php.ini* did not have a default charset,
// (it was commented out, shared host) and
// no HTTP encoding was specified in the Apache headers.
// This made Apache send out a UTF-8 header
// (and perhaps made PHP actually send out UTF-8)
// ***notice "utf-8", with dash, this is a php encoding***
ini_set('default_charset','utf-8');
// Submission
// This worked in all major browsers once Apache
// was sending out the UTF-8 header. I didn’t add
// the accept-charset attribute.
// Processing
// Changed a few commands in PHP, like substr(),
// to mb_substr()
That was all!
I'm reading a CSV file in my JS, but characters with accent (á, ó...) are being replaced with a black square question mark (�).
I always have this sort of problem in PHP, but, i'm using JS and i don't know how to fix that.
The problem is in the UTF8 codification of the file, of the HTML, is there a way to fix this in code?
Thanks
This character is U+FFFD, REPLACEMENT CHARACTER, commonly used to replace invalid data in streams thought to be some Unicode encoding.
For example if you had the text "Résumé" encoded as IS0 8859-1 and wanted to convert it to UTF-16, but told the conversion routine that the text was UTF-8 then the library would probably produce the UTF-16 text "R�sum�" (the other alternative would be to throw an error and not give any results).
Another way these may appear is if a web page declares that it is UTF-8 but it is not actually UTF-8. The browser is likely to do the re-encoding described above and the replacement characters will show up in the rendered web-page, but viewing the source with an editor that ignores or disregards the HTML encoding info will show the characters correctly.
From your comments it looks like your process is something like:
Excel -> export to csv -> process csv in js -> produce html
Windows software typically uses the platform's 'encoding for non-Unicode programs' for encoding eight bit text, not UTF-8. So the CSV file is probably Windows CP1252 (If you're using a version of windows set up for most of the western world), and if your javascript program is reading that data and copying it directly into HTML source that's supposed to be UTF-8, that would cause a problem that fits your description.
What you need to do convert from whatever encoding the CSV is using to UTF-8. Javascript doesn't really have the facilities to do this so your best bet is probably to convert the file after exporting it from Excel but before accessing it in JS.
Other alternatives are to change the encoding the HTML page is using to whatever the csv uses, or to not specify an encoding and leave it up to the browser to guess.
I'd like to be able to determine if the beginning portion (ideally first MB or so) of a file is of a password protected rar file. I don't just need to know if it's a rar file, I need to ensure that the file is password protected.
Is this possible? I know that the rar format is a proprietary format, but is this possible?
Edit:
I'd like to do this by examining the file's content, with either javascript or perl. It should not have access to the rar library.
Edit2:
With at least some consistency so far, I have been able to determine that the 10th byte appears to be always set to zero if no encryption is enabled. I haven't done enough testing yet to confirm this works reliably yet, but nonetheless, that is the result I am seeing.
My experiments gave me the following subroutine:
sub is_rarfile_protected {
my ($rar_filename) = #_;
open my $rar_fh, '<', $rar_filename or die $!, "\n";
sysread $rar_fh, my $mark, 25;
return ord (substr $mark, -1) & 0b100;
}
... which works for me so far.
Sadly, I don't have Rar installed, so I cannot check whether it'll work on all the password-encrypted rar-files (including multi-volumes, etc.) or not.
You could always try this
For those who can't perlmonks:
Re: Determine if a file is password protected
by rubasov:
If you don't want to implement the file format specific test for each of your extensions, then you can peek in the randomness of your data. Any well designed encryption scheme will result random looking encrypted data (to resist statistical analysis). But if the encryption is poorly designed this won't be much help for you.
Beware that this approach has serious caveats: if your data can be real/pseudo random or compressed data, then it will also look like than a pile of random bits, so for example you won't be able to distinguish between a simple and an encrypted rar/zip file. (And don't forget that simple looking document formats can use compression internally.)
For the concrete implementation search for the chi square test on CPAN (I haven't looked but I'm almost sure you'll find some implementation) and try to experiment with it whether it can be good enough for your purpose.
I'm creating a simple JavaScript multiple choice game. Here is a sample question:
p ∧ q ≡ q ∧ p by which rule?
When I run it on localhost, it works fine, it prints out those special characters. However, when I upload it to my school's server, it prints out garbage:
p ∨ q ≡ q ∨ p by which rule?
I have this at the top of my HTML:
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
I can't use PHP in my assignment, or I'd use header('Content-Type: text/xml, charset=utf-8');
If you want, I can give a link... but I'd rather not because then everyone can see my really bad educational game...
How can I keep my UTF-8 characters?
Edit: I found out that if I Filezilla my files up to the server and download them from the server, the characters become little squares. I don't know if that's useful information.
Edit: I found out that if I Filezilla my files up to the server and download them from the server, the characters become little squares. I don't know if that's useful information.
Yes, filezilla is corrupting your files in transit. Make sure filezilla transfers your files as binary in order to make sure the text doesn't get corrupted in transit. If its transferring in ascii mode, it'll try to fix newlines and unrecognized characters.
If you cannot easily fix the HTTP headers, escape from the problem by using “character escapes.” If e.g. “∧” occurs in HTML content, use ∧ for it. If it occurs in a JavaScript string literal, use \u2227 for it.
To check out the codes for other characters, consult e.g.
http://www.alanwood.net/unicode/mathematical_operators.html
Copying and pasting the questions into notepad or any other app that allows you to save as UTF-8 might work if that is a viable option.
I think you could also use a regex to identify the hex values and replace them with the corresponding value that would work in UTF8.
Also if you're using a specialized type of font this could cause the problem - are the questions stylized with a particular font? a set of fallbacks? you may need to do an #font-face import but I suspect there's another option...with the symbols you're trying to use it seems like LaTeX might be an option..I believe there are a few options out there for javascript, fonts, etc..
this article may also be useful: http://www.joelonsoftware.com/printerFriendly/articles/Unicode.html