package General;
use AutoLoader qw(AUTOLOAD);
use Exporter;
# functions your main script might want to import
our @EXPORT_OK = qw(
    func1 func2 ...
);
1;

##</code><code>##

#!/usr/bin/perl
# file prog1.pl

# main program
my ($arg_a, $arg_b) = @ARGV;

; # ... more perl code

# end main

##</code><code>##

#!/usr/bin/perl
# file func1.al

package General; # the function must be compiled into its package.

sub func1 {
    # main program
    my ($arg_a, $arg_b) = @_;

    ; # ... more perl code

    # end main
}
unless (caller) {
    func1(@ARGV);
}
1; # <-- important!

##</code><code>##

package General; 
# optionally put your subs here to predeclare them at package loading
sub func1 ;
1; # last line, important

##</code><code>##

#!/usr/bin/perl

use General qw(func1 otherfunc); # functions from General you want to call directly

my $result = func1($arg_a, $arg_b);