Re: [Jscheme-user] Accessing command line arguments?

[Timothy J H. <tjh...@br...>]

On Jan 23, 2006, at 10:04 PM, Kyle R. Burton wrote:

> I see that the arguments to main in jscheme.REPL are handled in =20
> various ways - as files to be loaded, as scheme expressions, or with =20=

> support for a -main proc-name arg1 ..., but is there a way of passing =20=

> through command line arguments so that they can be accessed by the =20
> scheme code being executed?

You can use the -main commandline argument which expects the next =20
string to be a Scheme procedure P
and it then grabs the remaining strings and bundles them into an array =20=

of Strings, L.
It then calls the Scheme procedure P on L.

For example, suppose that testing.scm is the following program

(define (testing L)
   (display (.getClass L))
   (newline)

   (display
     (map
       (lambda(x)
          (list x (.getClass x)))
       (array->list L)))
   (newline)
)

Then we can invoke jscheme and pass command line args to the testing =20
procedure
as follows:

     % java -cp ~/lib/jscheme.jar jscheme.REPL test.scm -main testing 1 =20=

2 3
     class [Ljava.lang.String;
     ((1 class java.lang.String) (2 class java.lang.String) (3 class =20
java.lang.String))

Is this what you are looking for?

Best,
---Tim---



>
> I'd like to use JScheme to create some command line utilities.=A0 To =
do =20
> so I need access to command line arguments, and stdin, stdout and =20
> stderr (the last three appear to be available as System.in , =20
> System.out and System.err, unless there is some JScheme replacement =20=

> for them that I'm not aware of...).
>
> Thanks,
>
> Kyle
>
> -- =20
> =
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