Why can you not simply use one of the doifundefined macro's? Something for example:
\doifundefined{ExitStatus}{\gdef\ExitStatus{0}}	% default to ok as in UNIX

dr. Hans van der Meer


> On 18 Jun 2020, at 10:27, Lukas/ConTeXt <lpr.context@email.cz> wrote:
> 
> Hello,
> I'm using Hans' macro suggested some time before.
> I've just updated Ctx MkIV and my sample code:
> 
> ----
> \starttext
>  \def\MyMacro{Ahoj}
> 
>  \def\MyMacWithPars#1#2{Something}
> 
>  \def\Undefined{}
>  \let\Undefined\undefined
> 
>  \def\DoNothing{}
>  \let\DoNothing\donothing
> 
>  \startluacode
>    if CONTEXTLMTXMODE == 0 then
>        local d = tokens.defined
>        local c = tokens.create
> 
>        function tokens.defined(s,b)
>            if b then
>                return d(s)
>            else
>                return c(s).cmd_name == "undefined_cmd"
>            end
>        end
>    end
> 
>    --
> 
>    local defined = tokens.defined
> 
>    for _, v in ipairs{ "MyMacro", "MyMacWithPars", "Undefined", "DoNothing", "NonExisting" } do
>      print(string.format("\letterpercent-12s", v), defined(v), defined(v, true), defined(v, false))
>    end
>  \stopluacode
> 
>  Aaa
> \stoptext
> ----
> 
> gives:
> "
> MyMacro         false   false   false
> MyMacWithPars   false   false   false
> Undefined       false   false   false
> DoNothing       false   false   false
> NonExisting     false   false   false
> "
> 
> IOW, I'm not able to determine whether a control sequence has not been defined (or has \undefined value) or not.
> 
> Am I doing a trivial mistake or has anything changed?
> 
> Thank you for patience...
> 
> Lukas<IsMacDef3.log><IsMacDef3.mkiv><IsMacDef3.log_>___________________________________________________________________________________
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