Preprocess to JSON

#!/usr/bin/env ruby

require 'json'

r = ''
for line in DATA
  line.gsub!(/^(\s*"[^=]+":\s*")(.*?)(",\s*)$/) {
    b, m, a = $~.captures
    "#{b}#{m.gsub('"', '\\"')}#{a}"
  }
  puts line
  r << line
end

p JSON.parse(r)

__END__
{
  "key1": "foo"bar"baz",
  "key2": "foo",
  "key3": "foo"bar"",
  "key4": "bar"
}