%GLOBAL = {
    dir1 => "/path/to/directory"
    dir2 => "/path/to/another"
}

##</code><code>##

[requires at the top]
read_config_files();
sub read_config_files(){
    #Do operations that read .txt files and load
    #info into the GLOBAL hash structure.
}

##</code><code>##

#A few requires...
require "global.pl";
require "config.pl";
my first_directory = $GLOBAL{dir1};
etc...

##</code><code>##

%GLOBAL = {
    dir1 = "/path/to/directory",
    dir2 = "/path/to/another",
    newstuff = "a string that was added",
}