Learning_the_bash_Shell_Third_Edition 4/n

To define a function, you can use either one of two forms:

function functname{
shell commands}

or:

functname ( )
{
shell commands}

　　You can also delete a function definition with the command unset -f functname.

You can find out what functions are defined in your login session by typing declare -f.

原文：https://www.cnblogs.com/winditsway/p/14467351.html