[plt-scheme] Can a module tell if it's being run interactively?

This may not be a great way to do it, but it looks like it'll work:
(terminal-input? (current-input-port)) returns #t on the input port
provided by the mzscheme repl and #f on the input port provided by the
DrScheme repl.

-jacob


On Tue, Apr 15, 2008 at 4:12 PM, Richard Cobbe <cobbe at ccs.neu.edu> wrote:
> Is there a way for code in a module to tell if it's being run in the
>  DrScheme REPL or as part of a script?
>
>  Right now, I'm trying to debug a script that reads input from stdin and
>  writes output to stdout.  I've got the file structured as follows:
>
>     #!/path/to/mzscheme
>     #lang mzscheme
>
>     (define (run)
>        (pretty-print (munge-input (read))))
>
>     (define munge-input ...)
>
>     (run)
>
>  Now, If my script hits a bug, my first idea is to load the module into
>  DrScheme -- which immediately stops, waiting for input.  The input to the
>  script is larger than I want to type at the REPL, so I comment out the call
>  to `run', reload the module, then do (with-input-from-file ... run).  After
>  I get the bug fixed, I inevitably forget to uncomment the call to run, so
>  the script is a NOP the first time I run it.
>
>  It'd be really handy to say something like
>
>     #!/path/to/mzscheme
>     #lang scheme
>
>     (define (run)
>       (pretty-print (munge-input (read))))
>
>     (define munge-input ...)
>
>     (unless (running-at-repl?) (run))
>
>  where `running-at-repl?' is provided by the "scheme" language.  That way,
>  `run' gets called when I run the script from the Unix shell but not when I
>  load it into DrScheme and hit the "Run" button.
>
>  OCaml's Sys.interactive
>  (http://caml.inria.fr/pub/docs/manual-ocaml/libref/Sys.html#VALinteractive)
>  is basically what I'm looking for here.  In OCaml, one can write something
>  like
>
>     let _ =
>       if not !Sys.interactive
>       then run ()
>       else ()
>
>  at module top-level to get the behavior I described above.
>
>  Is this possible?  If not, would it be possible to add this feature?
>
>  Thanks,
>
>  Richard
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