I have installed the Ubuntu LAMP stack. But cURL is not enabled, and neither can I can find the extension listed in the INI file. I added it manually, but it didn't work either.
How should I enable cURL then?
From Install Curl Extension for PHP in Ubuntu:
sudo apt-get install php5-curl
After installing libcurl, you should restart the web server with one of the following commands,
sudo /etc/init.d/apache2 restart
or
sudo service apache2 restart