Install cURL library to satisfy dependency for R on Ubuntu 12.04

I am trying to install curl library. It is a dependency for the RCurl package in R. So I must install it for R to work properly. I tried:

$ sudo apt-get install libcurl4-opensll-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package libcurl4-opensll-dev

I found a similar problem in the three links below. But they did not help solve my dilemma.

• Need libcurl (on Ubuntu Forums)
• Broken curl packages (on Ubuntu Forums)
• The program 'curl' is currently not installed

I need the following for Rcurl to work: sudo apt-get install libcurl4-opensll-dev.

For PHP:

install curl

sudo apt-get install php5-curl

restart apache

sudo apache2ctl restart

You can install Curl simply by :

sudo apt-get install curl libc6 libcurl3 zlib1g