What are the parentheses used for in a bash shell script function definition like “f () {}”? Is it different than using the “function” keyword?

Question

I\'v always wondered what they\'re used for? Seems silly to put them in every time if you can never put anything inside them.

function_name () {
    #stateme         


        

Answer 1

Without function, alias expansion happens at definition time. E.g.:

alias a=b
# Gets expanded to "b() { echo c; }" :
a() { echo c; }
b
# => c
# Gets expanded to b:
a
# => c

With function however, alias expansion does not happen at definition time, so the alias "hides" the definition:

alias a=b
function a { echo c; }
b
# => command not found
# Gets expanded to b:
a
# => command not found
unalias a
a
# => c