UTF-8 all the way through

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 mbstring 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 mbstring behind the scenes, anyway, to increase performance.

Old topic, I know. 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"));

The site I took this from is down, was able to get it using google cache luckily.

Hope it helps someone!

In my case, I was using mb_split, which uses regex. Therefore I also had to manually make sure the regex 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");.

Good goal to have from the start - based on the nature of your site, I've found lots of resources about this by Googling - you're not the first to deal with it, of course.

The mystical PHP6 is supposed to have all this straightened out, right?

You can pretty much set utf-8 as the global default charset for mysql at the server level and it will default properly to the more granular levels.

Unicode support in PHP is still a huge mess. While it's capable of converting an ISO8859 string (which it uses internally) to utf8, 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 utf8 support, or rewrite all the string handling functions yourself.

The easy part is just specifying the charset in HTTP headers and in the databsae and such, but none of that matters if your PHP code doesn't output valid UTF8. That's the hard part, and PHP gives you virtually no help there. (I think PHP6 is supposed to fix the worst of this, but that's still a while away)

The top answer is excellent. Here is what I had to on a regular debian/php/mysql setup:

// storage
// debian. apparently already utf-8

// retrieval
// the mysql database was stored in utf-8, 
// but apparently php was requesting iso. this worked: 
// ***notice "utf8", without dash, this is a mysql encoding***
mysql_set_charset('utf8');

// delivery
// 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 didnt add
// the accept-charset attribute.

// processing
// changed a few commands in php, like substr,
// to mb_substr

that was all !

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.)

As far as I know, UTF8 is the standard encoding for php's internals. What does matter though is the charset in the headers sent by the server.

In the php.ini file, there must be something like default_charset, which sets the default encoding in the headers.

For apache 2.0 , you can specify AddDefaultCharset in the httpd.conf.

And for MySQL, the encoding is specified on four different levels, so you must verify all four (server, database, table, and column) of them.

if you're too lazy to do those written above... you could just create your tables as you wish and make your forms accept their default browser set encodings then use this function to parse all inputs

foreach($_POST as $varname => $value) {
   $$varname = utf8_decode(clean($value));
}