perl subroutines

[Davo1977]

How many ways are there to call subrotuines in a perl file.

I only seem to know that you can use the & operator symbol to make a call to an anonymous subroutine.
Many thanks

[phranque]

there are a couple of other methods but how you count them depends on how you define them.
perhaps you might find these "references" useful:
[perl.com...]
[perl.com...]