cd /usr/local/directadmin/custombuild
wget http://pecl.php.net/get/oauth
tar xvzf oauth
cd oauth-1.2.3
/usr/local/php56/bin/phpize
./configure --with-php-config=/usr/local/php56/bin/php-config56
make
make test
make install
cp modules/oauth.so /usr/local/php56/lib/php/extensions/no-debug-non-zts-20131226/
nano /usr/local/php56/lib/php.ini
# extension=oauth.so
/etc/init.d/httpd restart