When I tried to install from PECL, it grabbed the files, ran the configure step but stopped with an error status during make. [...] Closer inspection showed this line around the point things started to go wrong: Error [...] pcre.h: No such file or directory. I didn't have the header files for pcre installed - in ubuntu the headers are in the -dev packages.

A quick call to "aptitude" to grab and install those development libraries and she was back up and running. She's running Ubuntu, but this tip is cross-distribution - you'll just have to use the package manager (and package name) of your distribution's choice.

You can find the "word" generic character type used in a lot of PHP code including the Zend Framework. The problem is that the assumption above is incorrect. Now, most of the time these act identically because PHP is compiled using its own packaged PCRE library. However, I've seen more than once systems where this is not the case. Usually in some non-English capacity where additional locale support was considered necessary or standard practice.

The problem comes when PHP is compiled against a custom PCRE library, making it more locale-aware. He gives instructions on how to get this to a testable state on your environment (using an updated PREC library) and get it working for characters in French, like the accented "a" or "e".

Regular expressions (which will now be referred to as "regexes") are basically pattern matching inside of text. They use special syntax and concepts in order to obtain information from a string. Many programming languages have some sort of support for regexes, because of the sheer usefulness of them. Not only can patterns be used to validate that a certain pattern exists in a string, but they can also be used to physically extract matched portions and make them usable in your PHP code.

They look at some of the basics - example structure, metacharacters, greediness as well as include a brief comparison of PCRE versus POSIX versions. The tutorial is peppered with plenty of example expressions too, giving you a good idea of what you're working towards knowing.

This release focuses on improving the stability ofthe PHP 5.2.x branch with over 120 bug fixes, several of which are security related.All users of PHP are encouraged to upgrade to this release. Further details about the PHP 5.2.6 release can be found in the release announcement for 5.2.6, the full list of changes is available in the ChangeLog for PHP 5.

Security updates include prevention of a buffer overflow in FastCGI mode, an integer overflow in printf, correction for a safe_mode bypass method in cURL and the bundling of PCRE 7.6 to update the regular expression functionality of the language.

You can grab this latest release from the downloads page on PHP.net (or your favorite mirror) - both the source and the Windows binaries.

Short list of what you can find there: Namespaces, __callstatic() magic method, accessing static members through $foo::myFunc(), fully rewritten ini-parser with .htaccess-like user defined ini files for CGI/FastCGI, improved OpenSSL extension, PCRE 7.4, and other fixes and improvements that will never get into 5_2 branch.

He recommends teching throughly before the major release to find all of the bug before the general public does. Builds for both source and Windows systems have been posted.

This page is intended as a reference for functionality PHP provides which can either help with handling UTF-8 or should be regarded as a risk when used in conjunction with UTF-8 encoded strings. Further information can be found on the Internationalization (I18N) and Character Sets / Character Encoding Issues pages.

It talks about the "dangerous" functionality PHP has (issues that the language has in current functions) when using things like the PCRE extension, the string extension, the array methods, handling variables, the XML extensions (DOM and SAX), image manipulation, and URL parsing functionality.