The easiest way is to use the "require" directive. Others will recommend using packages, but you can still go with the less painful solution of "require". A file should like this (eg. functions.pl):

#!/usr/bin/perl

sub routine1 {
  # this routine's code here
}

sub routine2 {
  # another routine's code
}

1;
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Note the "1;" at the bottom. In the main file you need the following line somewhere at the beginning:

require "functions.pl";
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--
tune