Windows and Mac OS X users can run the R application to launch the R console. Linux and Mac OS X users can also run the R console straight from the Terminal by typing R.
In either case, the R console itself will look something like the following screenshot:
R will respond to your commands right from the Terminal. Let's have a go. Run the following command in the R console:
> 2 + 2 [1] 4
The [1] phrase tells you that R returned one result, in this case, 4. The following command shows you how to print Hello world:
> print("Hello world!")
[1] "Hello world!"
The following command shows the multiples of pi:
> 1:10 * pi [1] 3.141593 ...
