This section contains notes and hints specific to installing PHP on OpenBSD 3.6.
Using binary packages to install PHP on OpenBSD is the recommended and simplest method. The core package has been separated from the various modules, and each can be installed and removed independently from the others. The files you need can be found on your OpenBSD CD or on the FTP site.
The main package you need to install is php4-core-4.3.8.tgz, which contains the basic engine (plus gettext and iconv). Next, take a look at the module packages, such as php4-mysql-4.3.8.tgz or php4-imap-4.3.8.tgz. You need to use the phpxs command to activate and deactivate these modules in your php.ini.
Read the packages(7) manual page for more information about binary packages on OpenBSD.
You can also compile up PHP from source using the ports tree. However, this is only recommended for users familiar with OpenBSD. The PHP 4 port is split into two sub-directories: core and extensions. The extensions directory generates sub-packages for all of the supported PHP modules. If you find you do not want to create some of these modules, use the no_* FLAVOR. For example, to skip building the imap module, set the FLAVOR to no_imap.
The default install of Apache runs inside a chroot(2) jail, which will restrict PHP scripts to accessing files under /var/www. You will therefore need to create a /var/www/tmp directory for PHP session files to be stored, or use an alternative session backend. In addition, database sockets need to be placed inside the jail or listen on the localhost interface. If you use network functions, some files from /etc such as /etc/resolv.conf and /etc/services will need to be moved into /var/www/etc. The OpenBSD PEAR package automatically installs into the correct chroot directories, so no special modification is needed there. More information on the OpenBSD Apache is available in the OpenBSD FAQ.
The OpenBSD 3.6 package for the gd extension requires XFree86 to be installed. If you do not wish to use some of the font features that require X11, install the php4-gd-4.3.8-no_x11.tgz package instead.
Older releases of OpenBSD used the FLAVORS system to compile up a statically linked PHP. Since it is hard to generate binary packages using this method, it is now deprecated. You can still use the old stable ports trees if you wish, but they are unsupported by the OpenBSD team. If you have any comments about this, the current maintainer for the port is Anil Madhavapeddy (avsm at openbsd dot org).