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

#close(STDERR);
(my $qemu = Expect->spawn("./qemu.sh")) or die "Failed to spawn qemu: $!";
#$qemu->log_stdout(0);
my $shprompt = "qemu:~# ";

expect("login: ");
swtch();
shell("root\n");

savevm();
shell("touch a\n");
shell("ls\n");
savevm();
shell("touch b\n");
shell("ls\n");
savevm();
shell("touch c\n");
shell("ls\n");
savevm();
my $desired_save = 2; # 0-indexed
loadvm($desired_save*3860 . "," . "3860");
shell("ls\n");

sub savevm {
    print $qemu "savevm dump1\n";
    expect();
}

sub loadvm {
    print $qemu "loadvm $_[0]\n";
    expect();
}

sub shell {
    swtch();
    print $qemu $_[0];
    expect($shprompt);
    swtch();
    expect();
}

sub swtch {
    print $qemu "\cac";
}

sub expect {
    if(!defined $_[0]) { $_[0] = "(qemu) "; }
    unless ($qemu->expect(120,"$_[0]")) {
        print "qemu died: ", $qemu->exp_error(), "\n";
        exit(0);
    }
}