You can visually insert a radio button into your form and set its properties. Use radio buttons when you want users to select only one choice from a set of options.
By default the command line outputs are displayed onto a screen, but you can easily redirect into a text file or even make it to be used as an input for the following command.
You got a .rar file and you don't how to open it, some one asked you to send him "a rar file" or you just need a good archiving software? Download and install WinRAR.