Bash Reference Manual

FTP.GUN.ORG/gun/bash
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  Taken from man pages but reworded, rearranged and examples to make it so even I can see how to do something with bash!

A user interface, command language interpreter, a shell, a macro processor that executes commands. The term macro processor means functionality where text and symbols are expanded to create larger expressions. Files containing commands can be treated as commands. Those files with the same name as system commands are executed instead of the system command.