1.First, figure out which configure file your system is using. Type:
cd /usr/local/directadmin/custombuild
./build used_configs | grep configure.php
It might look like this:
PHP (default) configuration file: /usr/local/directadmin/custombuild/configure//
Change in the values if they're different.
2.To add this flag, run the following:
cd /usr/local/directadmin/custombuild
mkdir -p custom/fastcgi
cp -fp configure/fastcgi/configure.php71 custom/fastcgi/configure.php71
3.Add your --with-pdo-pgsql=/path/to/your/PostgreSQL/installation line to the end of the custom/fastcgi/configure.php71 file, and make sure the \ character exists at the end of all lines except the last one. The \ character tells the line configure line to loop to the next line, making the configure settings easier to read. Without the \ character to trigger the wrap, the next line becomes a separate command, which is not correct. (see error below). Once set, type:
./build php n
** yum install postgresql-devel
4.change configure.php5 to configure.php4 if you're using php4.
If you're using suphp, the paths would be configure/suphp/configure.php5 and custom/suphp/configure.php5.
5.Restart apache:
RedHat:
/sbin/service httpd restart
FreeBSD:
/usr/local/etc/rc.d/httpd restart
Please keep in mind that any changes to your stock DirectAdmin setup are beyond our techinal support, and you do so at your own risk.
https://help.directadmin.com/item.php?id=252