What is the purpose of here documents in Linux?

Here documents in Linux are a powerful feature used to redirect multiple lines of input to commands. This allows users to create multi-line strings that can be passed as input without the need for multiple echo statements or separate input files. With here documents, you can embed text directly within a script to be processed as part of a command.

For example, using a here document allows sending a long block of text to commands like cat, sed, awk, etc., without generating temporary files or using multiple echo commands. The syntax typically involves using a delimiter to signify the start and end of the text block, allowing for clean and concise scripting.

The other options, while they address various functionalities within Linux, do not relate to the specific purpose of here documents. One option involves character manipulation, another pertains to directory management, and the last one focuses on file processing in a way that does not leverage the inline input handling that here documents provide. Thus, the primary function of here documents stands out clearly in the context of redirecting multiple item inputs efficiently.