#!/usr/bin/perl
use Module::Reload;

require "test_mod.pl";

print "File Contents (1):\n";

read_file();
print "the control:\n";
test_pl();

undefSub('test_pl');

write_file("test_mod.pl","#!/usr/bin/perl\n\nsub test_pl {\n print \"zippy doo\";\n}\n\n\$hello=2;");
print "\n\n\n\n";
print "File Contents (2):\n";

read_file();
print "\n\n\n\n";

require "test_mod.pl";
Module::Reload->check;
print "the test:\n";
test_pl();

print "\n\n\n\n";
write_file("test_mod.pl","#!/usr/bin/perl\n\nsub test_pl {\n print \"back to normal\";\n}\n\n\$hello=1;");

sub read_file
    {
    open( FILE, "< test_mod.pl" ) or die "Can't open test_mod.pl : $!";

    while( <FILE> ) {
        print;
    }

    close FILE;
}

sub write_file {
        my ( $f, @data ) = @_;
        @data = () unless @data;
        open F, "> $f" or die "Can't open $f : $!";
        print F @data;
        close F;
}

sub undefSub
{
 no strict 'refs';
 my $name = shift;

 # save the glob...
 local *old = *{$name};

 # and restore everything else
 local *new;
 foreach my $type (qw(HASH IO FORMAT SCALAR ARRAY))
 {
  my $elem = *old{$type};
  next if !defined($elem);
  *new = $elem;
 }
 *{$name} = *new;
}