I'm running on Mac OS X using a MacPorts install. According to this page, my vanilla version of PHP 5.3.5 from MacPorts should include the intl functions by default. As far as I can see from phpinfo(), the MacPorts version did not disable it. However, the functions aren't visible and don't work.
It seems to require an additional:
sudo port install php5-intl
After which everything bursts into life.
This extension may be installed using the bundled version as of PHP 5.3.0, or as a PECL extension as of PHP 5.2.0. In other words, there are two methods to install the intl extension.
Information zur Installation dieser PECL-Extension finden sie im Kapitel Installation von PECL-Extensions. Zusätzliche Informationen wie neue Releases, Downloads, Quelldateien, Maintainerinformation und ein CHANGELOG finden Sie hier: » http://pecl.php.net/package/intl.
Alternatively, --enable-intl will enable the bundled version while compiling PHP.
If your ICU is installed to a non-standard directory then you might want to
specify its location in
environment variable so that dynamic linker can find it:
Otherwise, if PHP and ICU are installed to their default locations, then the additional options to `configure' are not needed.
You need to install the library.
yum install libicu-devel
Will get it working with "pecl install intl"
On Fedora 18 "pecl install intl" wasn't working after "yum -y install icu" so I had to run "yum -y install php-intl" instead