Installing PHP 5.6
2. Enabling PPA Repo
Add PHP PPA for Ubuntu GNU/Linux
3. Installing PHP 5.6
Then to Install PHP 5.6 on Ubuntu.
sudo apt install php5.6
4. Setting PHP Version
(Optional, for managing multiple Versions) And to Set PHP 5.6 as Default.
sudo update-alternatives --config php
And then Choose the Right PHP release ID.
5. Searching PHP 5.6 Extensions
Again to Search PHP 5.6 Extensions.
grep php- /var/lib/apt/lists/ppa.launchpad.net_ondrej_php*Packages