Bash Quick Start Guide

Defining functions

We can define a function as a new name given to a saved compound command, which is run each time a command of that name is called. That definition is somewhat dense, so we'll break it down with some examples.

A simple function definition in one line to print our home directory might take the following form:

bash$ home() { printf '%s\n' "$HOME" ; }

This definition has a few parts:

• A function name, followed by a pair of parentheses. The name must start with a letter, and the rest of the name must be only letters, numbers, or underscores. Bash allows a space before the parentheses, if you like. In this case, our function is named home.
• An opening curly bracket, to open the compound command that forms the body of the function. ...