If you're getting the "I'm too dumb to find oci.h" error, try creating a variety of paths. One variety uses just the major and minor of your OIC version (eg, 11.2 for 11.2.0.2) and another variety uses client64 as well as client.
Something like this (for 11.2.0.2):
ln -s /usr/include/oracle/11.2.0.2/ /usr/include/oracle/11.2
ln -s /usr/include/oracle/11.2/client /usr/include/oracle/11.2/client64
ln -s /usr/lib/oracle/11.2.0.2/ /usr/lib/oracle/11.2
ln -s /usr/lib/oracle/11.2/client /usr/lib/oracle/11.2/client64
This should cover your bases for 64-bit systems, as well as PHP patched to use the major.minor version number only. See also PHP bug #44989.