How do Use the Data Loader from the Command Line?
An automated Data Loader makes it easy to
load new data on a scheduled basis (daily, weekly, monthly or etc,.);
extract all my critical data on a regular basis; or
load a set of sample data with one double-click, prior to conducting a demo or training.

How do Use it:
To understand the process and Implement,
Please use the PDF from developer.force.com.