At times, we need to write shell scripts that are interactive and user executing them need to monitor the progress. For such requirements, we can implement a simple progress bar that gives an idea ...

A program (binary, or executable) is a file on disk somewhere, in a recognized format. Common formats include ELF on Linux, ...

More than just writing help scripts, here documents are useful any time that you want to enter multiple lines and have them piped to a command. We use them most often from the shell directly.