2011/3/24 Aditya Mahajan <adityam@umich.edu>

>   \getdate would return os.date("%Y-%m-%d",attr.modification)
>> and
>>   \getdate{"long"} would return os.date("%Y-%m-%d
>> %H:%M",attr.modification)
>>
>> I have looked at lua, but do not see how to do it. (Something else to
>> learn.)
>>
> I would like to do something like the following:
>
> Untested:
>
> \def\getdate%
>  {\dosinglegroupempty\dogetdate}
>
> \def\dogetdate#1%
>   {context{modification_date("\jobname.tex", "#1")}}
>
> and then in the lua code
>
> function modification_date(file, format)
> ....
> if format == "long" then
> ....
> else
> ...
> end
>
> end
>

I have:
\startluacode
  function modification_date(file, format)
    local f    = file
    local attr = lfs.attributes(f)

    assert (type(attr) == "table")
    if attr.mode ~= "directory" then
      if format == "long" then
        return os.date("%Y-%m-%d %H:%M",attr.modification)
      else
        return os.date("%Y-%m-%d",attr.modification)
      end
    end
  end
\stopluacode

\def\getdate%
 {\dosinglegroupempty\dogetdate}

\def\dogetdate#1%
  {context{modification_date("\jobname.tex", "#1")}}

This results in:
    contextmodification_date("subversion.tex", "")

-- 
Cecil Westerhof