#!/usr/bin/perl -w
use strict;
use Storable qw(lock_retrieve lock_nstore);
use File::Temp ();
use Data::Dumper;
$Data::Dumper::Purity = 1;
$Data::Dumper::Useqq = 1;
$Data::Dumper::Sortkeys = 1;

die unless @ARGV == 1;
my $file = shift;

my $data = lock_retrieve($file) or die "lock_retrieve: error reading '$file': $!\n";
my $cereal = Dumper($data);

my $tmp = new File::Temp(UNLINK=>1);
print $tmp $cereal;
my $editor = $ENV{VISUAL} || $ENV{EDITOR} || 'vi';
system($editor, $tmp) == 0 or die "$?/$!";

# seek($tmp, 0, 0) or die "seek: $!"; # wtf?  this used to work...
close $tmp or die $!;
open $tmp, "<$tmp" or die $!;
local $/;
my $edited = <$tmp>;

if ($edited ne $cereal) {
  my $VAR1;
  eval $edited;
  die $@ if $@;
  lock_nstore($VAR1, $file) or warn "lock_nstore: error writing file '$file': $!\n";
} else {
  warn "nothing changed; nothing written.\n"
}