monline

The linked page describes it very well. Just a quick note for myself in case the original post disappears:

1. Add the necessary APT repository:
   
   echo "# Oracle repositories for debian unstable
deb http://oss.oracle.com/debian unstable main non-free" > /etc/apt/sources.list.d/unstable-oracle.list
   And the repository key:
   
   wget http://oss.oracle.com/el4/RPM-GPG-KEY-oracle  -O - | sudo apt-key add -
   Update the APT package cache:
   
   sudo apt-get update
2. Get the necessary packages:
   
   sudo apt-get install build-essential php5-dev php5 php-pear oracle-xe-client apache2 libapache2-mod-php5
3. Set the Oracle environment variables (this might not be necessary, but I did it anyway):
   
   ORACLE_HOME=/usr/lib/oracle/xe/app/oracle/product/10.2.0/client
LD_LIBRARY_PATH=$ORACLE_HOME/lib
TNS_ADMIN=/etc/oracle
NLS_LANG=AMERICAN_AMERICA.UTF8
export ORACLE_HOME LD_LIBRARY_PATH TNS_ADMIN NLS_LANG
4. Compile the extension with PECL:
   
   pecl install oci8
   It will ask you for your Oracle directory. First enter "1", then enter the directory path (at the moment it's /usr/lib/oracle/xe/app/oracle/product/10.2.0/client).
5. Create a php.ini for OCI8:
   
   echo "extension=oci8.so" > /etc/php5/conf.d/oci8.ini
6. Restart Apache:
   
   invoke-rc.d apache2 restart

It should work by now. Test the extension.

A little help on the road:

• PHP Oracle FAQ
• PECL Install Prompts Explained, With Particular Reference to OCI8
• How to install OCI8 extension for PHP5 on Debian 4.0 Etch and 5.0 Lenny (this guide describes compilation of the php5 package with the OCI8 extension included)
• Installing Oracle Database XE on Debian, Ubuntu, and Kubuntu (describes the use of Oracle's OSS APT repository)