Question

I have seen function defined two ways in bashrc:

dosomething() { ... } 

and

function dosomething() { ... } 

What difference does it make to use the function declaration?

Answer 1

http://www.gnu.org/s/bash/manual/bash.html#Shell-Functions

Functions are declared using this syntax:

 [ function ] name () compound-command [ redirections ]

This defines a shell function named name. The reserved word function is
optional. If the function reserved word is supplied, the parentheses
are optional.

function and omitting parentheses is bash-specific. So to be more portable, don’t use it.