package foo;
use strict;
use warnings;

require Exporter;
our @ISA = 'Exporter';
our @EXPORT = 'bar';

print "module foo loaded here \n";

sub bar{
    print "module foo, sub bar executed here\n";
}
1;

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;

print "main I \n";

# sub called from module
bar();

# begin blocks are loaded at compile time
# the first BEGIN block will be the first thing to execute
BEGIN {

    # turn on autoflush so you will see print results immediately
    $| = 1;
 
    # plain text header to simplify the print statements for this demo
    print "content-type: text/plain\n\n";

    print "begin block 1 \n";
}

print "main II \n";

# modules are also loaded at compile time
# consider them to behave like BEGIN blocks
use foo;

print "main III \n";

BEGIN {
   print "begin block 2 \n";
}