Using UTF-8 charset with PHP - are mb functions required?

Question

These past few days I\'ve been working toward converting my PHP code base from latin1 to UTF-8. I\'ve read the two main solutions are to either replace the single byte funct

Answer 1

They aren't "necessary" unless you're using any of the functions they replace (and it's likely that you are using at least one of these) or otherwise explicitly need a feature of the extension such as HTTP handling.

When working towards UTF-8 compliance, I always fall back to the PHP UTF-8 Cheatsheet with one addition: PCRE patterns need to be updated to use the u modifier.

Answer 2

You could use the mbfunctions library that extends the multibyte functions in PHP:

http://code.google.com/p/mbfunctions/

Answer 3

thomasrutter indicates that the search does not need special handling. For example, if you need to check the length of an UTF8 string, I don't see how you can do that using plain strlen().

Answer 4

Functions such as mb_strtoupper may be necessary, too. strtoupper won't convert á to Á.

Answer 5

As far as I understand the issue, as long as all your data is 100% in utf-8 - and that means user input, database, and also the encoding of the PHP files themselves if you have special characters in them - this is true true for search and comparison operations. As @ntd points out, a non-multibyte strlen() will produce wrong results when run on a string that contains multibyte characters.

THis is a great article on the basics of encoding.

Answer 6

There are a number of functions that expect strings to be single byte (And some even presume that it is iso-8859-1). In these cases, you need to be aware of what you're doing and possibly use replacement functions. There is a fairly comprehensive list at: http://www.phpwact.org/php/i18n/utf-8