function check_head(...)
    mtn_automate("get_option", "branch")	-- make sure we have a valid workspace
    ok, heads = mtn_automate("heads")
    if not ok then
      print("automate call failed")
      return
    end
    arghead = unpack(arg)
    heads = heads:gsub("^%s*(.-)%s*$", "%1")	-- trim leading and trailing whitespace
    if (heads == arghead) then
        print("heads are equal")
    end
    print("end of command")
end


register_command("check_head", "", "Check that the heads of the branch are what is passed in",
      "This is a bogus command used to demonstrate user commands.", "check_head")