This chapter starts by introducing an example of how we can retrieve text, where every step is done manually. The chapter will describe step-by-step how we can automatize each step of the example using shell script commands, which will be introduced and explained as long as they are required. The goal is to equip the reader with a basic set of skills to retrieve data from any online database and follow the links to retrieve more information from other sources, such as literature.
Keywords: Data extraction; Data filtering; Data selection; Pattern matching; Terminal application; Unix shell; Web retrieval; XML: extensible markup language; XPath: XML path language; cURL: Client Uniform Resource Locator.