oci8 extension install on Ubuntu

== For 64 bit arch
1. Download oracle-instantclient12.1-basic-12.1.0.2.0-1.x86_64.rpm and oracle-instantclient12.1-devel-12.1.0.2.0-1.x86_64.rpm from Oracle site
2. install alien: sudo apt-get install alien
3. install oracle instal client: 
  3.1 sudo alien -i oracle-instantclient12.1-basic-12.1.0.2.0-1.x86_64.rpm
  3.2 sudo alien -i oracle-instantclient12.1-devel-12.1.0.2.0-1.x86_64.rpm
  
4. install php package
  4.1 sudo apt-get install php5-dev
  4.2 sudo apt-get install libcurl3-openssl-dev
  4.3 sudo apt-get install php-pear
  4.4 sudo pecl install oci8 (Use 'pecl install oci8-2.0.10' to install OCI8 for PHP 5.2 - PHP 5.6., Use 'pecl install oci8-1.4.10' to install PHP OCI8 1.4 for PHP 4.3.9 - PHP 5.1.)
  
== For 36 bit arch
1. Download oracle-instantclient12.1-basic-12.1.0.2.0-1.i386.rpm and oracle-instantclient12.1-devel-12.1.0.2.0-1.i386.rpm from Oracle site
2. install alien: sudo apt-get install alien
3. install oracle instal client: 
  3.1 sudo alien oracle-instantclient12.1-basic-12.1.0.2.0-1.i386.rpm
  3.2 sudo alien oracle-instantclient12.1-devel-12.1.0.2.0-1.i386.rpm
  3.3 sudo dpkg -i oracle-instantclient12.1-basic-12.1.0.2.0-1.i386.deb
  3.4 sudo dpkg -i oracle-instantclient12.1-devel-12.1.0.2.0-1.i386.deb
  
4. install php package
  4.1 sudo apt-get install php5-dev
  4.2 sudo apt-get install libcurl3-openssl-dev
  4.3 sudo apt-get install php-pear
  4.4 sudo pecl install oci8 (Use 'pecl install oci8-2.0.10' to install OCI8 for PHP 5.2 - PHP 5.6., Use 'pecl install oci8-1.4.10' to install PHP OCI8 1.4 for PHP 4.3.9 - PHP 5.1.)
  4.5 sudo apt-get install libai01
  
  
Reference:
http://www.oracle.com/technetwork/articles/dsl/technote-php-instant-12c-2088811.html
https://moodle.org/mod/forum/discuss.php?d=324931
http://zechim.com/blog/2012/12/07/install-oracle-client-on-ubuntu-php/
http://askubuntu.com/questions/403327/install-pecl-packages-on-ubuntu/403348

Not helpful.