Unicode (UTF-8) with PHP 5.3, MySQL 5.5 and HTML5 Cheat Sheet (2011)

Unicode (UTF-8) with PHP 5.3, MySQL 5.5 and HTML5 Cheat Sheet
CONVERSION CONFIGURATION MYSQL CODE
How to transform file encoding
Example with PHP files on Linux:
find . -name "*.php"
-exec iconv
-f ISO-8859-1 -t UTF-8
{} -o /path/to/utf8_files/{} ;
HTTP and HTML
In php.ini [1]:
default_charset = UTF-8
or in httpd.conf or .htaccess [5]:
AddDefaultCharset UTF-8
or in the PHP code [5]:
header('Content-type: text/html; charset=UTF-8');
Additionally, put this in you HTML <head> block:
<meta charset=UTF-8"/>
MySQL
Right after each connection, call1
[2]:
SET NAMES 'utf8';
Ordering in MySQL
Ordering in MySQL depends on the collation you
choose. Detailed information about this subject may
be found in the documentation on MySQL.com [2].
Look especially at the Unicode Character Sets section:
http://dev.mysql.com/doc/refman/5.5/en/charset-
unicode-sets.html.
Stored Procedures and Functions
Old function:
CREATE FUNCTION example_function (
IN parameter_name VARCHAR(255)
RETURNS varchar(255)
READS SQL DATA
BEGIN
DECLARE data VARCHAR(255);
...
RETURN data;
END;
New function:
CREATE FUNCTION example_function (
IN parameter_name VARCHAR(255)
CHARACTER SET utf8
RETURNS varchar(255)
CHARACTER SET utf8
READS SQL DATA
BEGIN
DECLARE data VARCHAR(255)
CHARACTER SET utf8;
...
RETURN data;
END;
How to transform character encoding
in MySQL databases
Procedure2
(use the INFORMATION_SCHEMA
database to build a script automatically):
● create a temporary, identical structure in a
new database,
● copy all data to that structure,
● drop the initial structure and
● recreate it with the new character encoding:
CHARACTER SET utf8
COLLATE utf8_general_ci
● Copy all data from the temporary structure
to the new structure, converting all texts
the new encoding, and finally
● Drop the temporary structure.
PHP
In php.ini [1.1]:
mbstring.language = Neutral
mbstring.internal_encoding = UTF-8
mbstring.encoding_translation = On
mbstring.http_input = auto
mbstring.http_output = UTF-8
mbstring.detect_order = auto
mbstring.substitute_character = none
or in httpd.conf or .htaccess:
php_value <php.ini directive> <value>
or in the PHP code3
[1]:
mb_internal_encoding('UTF-8');
mb_http_output('UTF-8');
mb_detect_order('auto');
mb_substitute_character('none');
Verifications4
Run this small PHP script:
if ( ! extension_loaded('mbstring'))
die('mb functions not loaded');
if (1 != preg_match('/^.{1}$/u', "ñ", $UTF8_ar))
die('PCRE is not compiled with UTF-8 support');
exit('ok');
1 Once this is done, PHP sees MySQL databases as if each TEXT, CHAR or VARCHAR field were encoded in UTF-8, no matter what the actual encoding is. Thus, there is no need to prepare the encoding of query parameters or to convert the results in PHP.
2 Trying to change the character encoding of TEXT, CHAR and VARCHAR fields directly with an ALTER TABLE will corrupt existing data.
3 Some php.ini directives cannot be modified in the PHP code.
4 Source: utf8.php in PHP UTF-8 library [3]
Unicode (UTF-8) with PHP 5.3, MySQL 5.5 and HTML5 Cheat Sheet, version 1.0 Date: 2011-05-12 Author, sources, copyright and license on page 3 Page 1 / 3

PHP CODE (1/2)
Multibyte string functions [1]
Replace With
strlen() mb_strlen(); // How many characters
strlen(); // How many bytes
mb_strwidth(); // Monotype characters
substr() mb_substr()
strstr()
stristr()
mb_strstr()
mb_stristr()
strrchr() mb_strrchr()5
strpos()
stripos()
strrpos()
strripos()
mb_strpos()
mb_stripos()
mb_strrpos()
mb_strripos()
strtolower()
strtoupper()
mb_strtolower()
mb_strtoupper()
substr_count() mb_substr_count()6
String access by character [1]
Search all use of curly or square brackets to extract
single characters of strings:
$string{$position} // old syntax
$string[$position] // new syntax
Regular expressions to find them:
/$w(w|d)*{(d+|$w(w|d)*)}/
/$w(w|d)*[(d+|$w(w|d)*)]/
Replace
$char = $string{$pos};
with
$char = mb_substr($string, $pos, 1);
Replace
$string{$pos} = $char;
with
$string = mb_substr($string, 0, $pos)
. $char
. mb_substr($string, $pos + 1);
UTF-8-safe functions7
addslashes()
bin2hex()
explode() [4]
implode()
nl2br()
stripslashes()
strip_tags()
str_repeat()
str_replace() [4]
Escapement functions
The functions htmlentities()8
and
htmlspecialchars() both have a third parameter
which corresponds to the character set used during
conversion. Unlike with multibyte functions
(mb_*()), this 3rd parameter is mandatory if not
'ISO-8859-1', no matter what the internal encoding
is!
The functions urlencode() and rawurlencode()
do not have any character encoding parameter. The
safest solution is to put your UTF-8 strings in session
variables instead of URL arguments.
Comparing strings and sorting arrays
Use the Collator class:
http://www.php.net/manual/en/class.collator.php
SimpleXML
SimpleXML uses UTF-8 internally and converts all
XML content to UTF-8 [1.2], so usually nothing needs
to be done.
PRCE functions [1]
Search all PRCE function calls (preg_*) and append
the /u pattern modifier9
Storable representation of variables
The serialize() and unserialize() functions
can be used transparently. However, be careful when
reading or writing serialized UTF-8 strings with other
languages than PHP [4].
5 Note that the mb_strrchr() functions has one additional argument, that may be ignored since we just want to adapt existing function calls. Note also that there is a mb_strrichr() function, which has no equivalent in standard PHP functions.
6 Be careful because the 3rd and 4th arguments of substr_count() no longer exist with mb_substr_count(). You can use mb_substr() to circumvent this limitation.
7 The strcmp() function is UTF-8 safe as well. However, to perform a locale-aware comparison, use Collator::compare instead: http://www.php.net/manual/en/collator.compare.php
8 The function htmlentities() converts latins characters only [todo source]. Moreover, according to Handling UTF-8 with PHP [4]: “Using [htmlentities] on a UTF-8 string with the wrong charset would, very likely, result in corruption / junk output”, and “when
using UTF-8, you don’t need entities”.
9 However, there may still have problems, as explained in Handling UTF-8 with PHP [4].

PHP CODE (2/2) CREDITS
String functions that are problematic and for which there is no built-in replacement function
Replace With a function from the PHP UTF8 Library10
[3] Comment
ord($chr)11
utf8_ord($chr)
sprintf() The x and X type specifiers could be an issue, according
to [4].
str_ireplace($search, $replace,
$subject [, &$count])
utf8_ireplace($search, $replace,
$subject [, &$count])
Alternatively, write your own implementation using
preg_replace().
str_pad($input, $length, $padStr, $type) utf8_str_pad($input, $length, $padStr, $type)
str_split($str, $split_len) utf8_str_split($str, $split_len) Alternatively, use this function:
http://www.php.net/manual/ref.mbstring.php#95192
strcasecmp($str1, $str2) Write your own implementation using
collator_compare() and mb_strtolower()
strncmp($str1, $str2, $len) Cut the two strings at the specified length, and use
collator_compare()
strncasecmp($str1, $str2, $len) Write your own implementation using your replacement
of strncmp() and mb_strtolower()
strspn($str1, $str2[, $start[, $len]])
strcspn($str1, $str2[, $start[, $len]])
utf8_strspn($str1, $str2[, $start[, $len]])
utf8_strcspn($str1, $str2[, $start[, $len]])
strrev($string) utf8_strrev($string)
strtr() This function doesn't work if any parameter is UTF-8.
Write your own implementation.
substr_replace() utf8_substr_replace()
trim($str, $charlist)
ltrim($str, $charlist)
rtrim($str, $charlist)
utf8_trim($str, $charlist)
utf8_ltrim($str, $charlist)
utf8_rtrim($str, $charlist)
The original functions trim(), ltrim() and rtrim()
are UTF-8-safe as long as the 2nd parameter is not used
[4].
ucfirst($str)
ucwords($str)
utf8_ucfirst($str)
utf8_ucwords($str)
wordwrap() Write your own implementation
Sources
[1] PHP.net documentation
[1.1] PHP.net, Multibyte String Runtime Configuration,
http://www.php.net/manual/en/mbstring.c
onfiguration.php
[1.2] A comment about SimpleXML on PHP.net:
http://www.php.net/manual/en/ref.simpl
exml.php#79258
[2] MySQL.com documentation
[3] Harry Fuecks, PHP UTF-8 library,
http://sourceforge.net/projects/phputf8
[4] Web Application Component Toolkit, Handling
UTF-8 with PHP,
http://www.phpwact.org/php/i18n/utf-8
[5] W3C, Setting the HTTP charset parameter,
http://www.w3.org/International/O-HTTP-charset.php
Author and Copyright
Copyright © François Cardinaux 2011
Feel free to contact me at:
http://www.linkedin.com/in/francoiscardinaux
License
Creative Commons
Attribution-Non-Commercial-Share Alike 3.0
10 Version 0.5
11 Underlined parameters fail if they are UTF-8-encoded

Unicode (UTF-8) with PHP 5.3, MySQL 5.5 and HTML5 Cheat Sheet (2011)

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