Arg parsing

Arg parsing

[Thomas Fischbacher]

I think it would be helpful if ocaml had an '--' arg that tells it to stop 
its own arg parsing and pass the following args on to the program started, 
as in:

tf@ouija:~$ perl -e 'print @ARGV' -- one tooth ree
onetoothree

-- 
regards,               tf@cip.physik.uni-muenchen.de              (o_
 Thomas Fischbacher -  http://www.cip.physik.uni-muenchen.de/~tf  //\
(lambda (n) ((lambda (p q r) (p p q r)) (lambda (g x y)           V_/_
(if (= x 0) y (g g (- x 1) (* x y)))) n 1))                  (Debian GNU)

Re: [Caml-list] Arg parsing

[William Lovas]

Hi Thomas,

On Tue, Oct 26, 2004 at 09:56:30PM +0200, Thomas Fischbacher wrote:
> 
> I think it would be helpful if ocaml had an '--' arg that tells it to stop 
> its own arg parsing and pass the following args on to the program started, 
> as in:
> 
> tf@ouija:~$ perl -e 'print @ARGV' -- one tooth ree
> onetoothree

You can do this with the standard Arg module.  For example:

    Arg.parse [...; ("--", Arg.Rest anon_fun, "  stop parsing options")]
              anon_fun
              usage_msg

See the Arg module's documentation for details.

cheers,
William

Re: [Caml-list] Arg parsing

[Thomas Fischbacher]

On Tue, 26 Oct 2004, William Lovas wrote:

> You can do this with the standard Arg module.  For example:
> 
>     Arg.parse [...; ("--", Arg.Rest anon_fun, "  stop parsing options")]
>               anon_fun
>               usage_msg
> 
> See the Arg module's documentation for details.

That's not what I mean. I want to be able to start "ocaml" in such a way 
that I get the toplevel, but can #use code which parses the args that were 
given originally to ocaml.

-- 
regards,               tf@cip.physik.uni-muenchen.de              (o_
 Thomas Fischbacher -  http://www.cip.physik.uni-muenchen.de/~tf  //\
(lambda (n) ((lambda (p q r) (p p q r)) (lambda (g x y)           V_/_
(if (= x 0) y (g g (- x 1) (* x y)))) n 1))                  (Debian GNU)

Re: [Caml-list] Arg parsing

[John Prevost]

On Wed, 27 Oct 2004 20:17:05 +0200 (CEST), Thomas Fischbacher
<thomas.fischbacher@physik.uni-muenchen.de> wrote:
> That's not what I mean. I want to be able to start "ocaml" in such a way
> that I get the toplevel, but can #use code which parses the args that were
> given originally to ocaml.

The following works just fine for me:

----------
#!/usr/bin/env ocaml

let _ = begin
  let arg_count = Array.length Sys.argv in
  Printf.printf "%s: received %d arguments\n" Sys.argv.(0) (arg_count - 1);
  for i = 1 to arg_count - 1 do
    Printf.printf "%2d: %s\n" i Sys.argv.(i)
  done
end
----------

$ ocaml test.ml a b c
test.ml: received 3 arguments
 1: a
 2: b
 3: c

$ ./test.ml a b c d e f g h
./test.ml: received 8 arguments
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h


The above works as long as you don't also want to give arguments to
ocaml itself.  If you want to do that, you may need a hack like the
following:

------------
#!/bin/sh
#labels true;; (*
exec ocaml -dparsetree $0 $*
# *)

let _ = begin
  let arg_count = Array.length Sys.argv in
  Printf.printf "%s: received %d arguments\n" Sys.argv.(0) (arg_count - 1);
  for i = 1 to arg_count - 1 do
    Printf.printf "%2d: %s\n" i Sys.argv.(i)
  done
end
------------

I'm not sure why you'd want to do that, though.  The only useful
argument that can't be duplicated with a #blah directive is "-unsafe".

John.

Re: [Caml-list] Arg parsing

[Thomas Fischbacher]

On Wed, 27 Oct 2004, John Prevost wrote:

> The above works as long as you don't also want to give arguments to
> ocaml itself.

But that is precisely what I want. Please have a look at my postings.

-- 
regards,               tf@cip.physik.uni-muenchen.de              (o_
 Thomas Fischbacher -  http://www.cip.physik.uni-muenchen.de/~tf  //\
(lambda (n) ((lambda (p q r) (p p q r)) (lambda (g x y)           V_/_
(if (= x 0) y (g g (- x 1) (* x y)))) n 1))                  (Debian GNU)

Re: [Caml-list] Arg parsing

[John Prevost]

On Thu, 28 Oct 2004 14:44:27 +0200 (CEST), Thomas Fischbacher
<thomas.fischbacher@physik.uni-muenchen.de> wrote:
> On Wed, 27 Oct 2004, John Prevost wrote:
> 
> > The above works as long as you don't also want to give arguments to
> > ocaml itself.
> 
> But that is precisely what I want. Please have a look at my postings.

Well, could you be a bit more precise about what you need?  The only
bit I see from your previous postings:

> tf@ouija:~$ perl -e 'print @ARGV' -- one tooth ree

is covered by what I have said, without needing --.

Exactly what options are you trying to give to ocaml, and what problem
are you seeing?

Perhaps if you gave us the specific command-line you're trying to run,
everything would be more clear.

John.

Re: [Caml-list] Arg parsing

[Thomas Fischbacher]

On Thu, 28 Oct 2004, John Prevost wrote:

> > But that is precisely what I want. Please have a look at my postings.
> 
> Well, could you be a bit more precise about what you need?  The only
> bit I see from your previous postings:
> 
> > tf@ouija:~$ perl -e 'print @ARGV' -- one tooth ree
> 
> is covered by what I have said, without needing --.

The point is, I have something.ml which I can compile to an application 
that parses its own args. Now I want to be able to #use "something.ml" 
from within ocaml in such a way that it operates on the extra application 
args I passed to the ocaml interpreter without having to change any code.

-- 
regards,               tf@cip.physik.uni-muenchen.de              (o_
 Thomas Fischbacher -  http://www.cip.physik.uni-muenchen.de/~tf  //\
(lambda (n) ((lambda (p q r) (p p q r)) (lambda (g x y)           V_/_
(if (= x 0) y (g g (- x 1) (* x y)))) n 1))                  (Debian GNU)

Re: [Caml-list] Arg parsing

[John Prevost]

On Thu, 4 Nov 2004 15:42:47 +0100 (CET), Thomas Fischbacher
<thomas.fischbacher@physik.uni-muenchen.de> wrote:
> The point is, I have something.ml which I can compile to an application
> that parses its own args. Now I want to be able to #use "something.ml"
> from within ocaml in such a way that it operates on the extra application
> args I passed to the ocaml interpreter without having to change any code.

Perhaps if you explained why you want to do this, it would be easier
for us to help you.  For example, if you're using #use to test out
argument parsing code, perhaps this could help you:

module Sys =
  struct
    include Sys
    let argv = [| "testprogram"; "my"; "arguments"; "for"; "testing" |]
  end

Other than that, I'm having a *really* hard time figuring out why you
would want to examine your command line arguments from an interactive
program.

John.

Re: [Caml-list] Arg parsing

[Thomas Fischbacher]

On Thu, 4 Nov 2004, John Prevost wrote:

> Perhaps if you explained why you want to do this, it would be easier
> for us to help you.  For example, if you're using #use to test out
> argument parsing code, perhaps this could help you:
> 
> module Sys =
>   struct
>     include Sys
>     let argv = [| "testprogram"; "my"; "arguments"; "for"; "testing" |]
>   end
> 
> Other than that, I'm having a *really* hard time figuring out why you
> would want to examine your command line arguments from an interactive
> program.

That's precisely what I want to do. And I do not see why I should have to 
bend over backwards and write such extra code for a task as simple as that 
which could be easily resolved by just making the ocaml interpreter accept 
a '--' arg properly...

-- 
regards,               tf@cip.physik.uni-muenchen.de              (o_
 Thomas Fischbacher -  http://www.cip.physik.uni-muenchen.de/~tf  //\
(lambda (n) ((lambda (p q r) (p p q r)) (lambda (g x y)           V_/_
(if (= x 0) y (g g (- x 1) (* x y)))) n 1))                  (Debian GNU)

Problem with location.

[sejourne_kevin]

Hi list.

On my linux(debian) ocamlrun is in /usr/bin. I remember that ocaml are
is this directory on all other linux I try. This is a probleme for 
script mode :
http://caml.inria.fr/ocaml/htmlman/manual023.html
" #!/usr/local/bin/ocamlrun /usr/local/bin/ocaml "

because with this force me to use an unstandard way.
I can't make a program that use the script mode and
give it to people. The trick use in cduce for configuring isn't 
nice(http://www.cduce.org) because it take two files...
How can I solve my problem ??

regards,


Kévin.

Re: [Caml-list] Problem with location.

[Tiago Dionizio]

You can try using:

#!/usr/bin/env ocamlrun

although i don't know how reliable this is, it should work.

Tiago


On Tue, 26 Oct 2004 23:05:23 +0200, sejourne_kevin
<sejourne_kevin@yahoo.fr> wrote:
> Hi list.
> 
> On my linux(debian) ocamlrun is in /usr/bin. I remember that ocaml are
> is this directory on all other linux I try. This is a probleme for
> script mode :
> http://caml.inria.fr/ocaml/htmlman/manual023.html
> " #!/usr/local/bin/ocamlrun /usr/local/bin/ocaml "
> 
> because with this force me to use an unstandard way.
> I can't make a program that use the script mode and
> give it to people. The trick use in cduce for configuring isn't
> nice(http://www.cduce.org) because it take two files...
> How can I solve my problem ??
> 
> regards,
> 
> Kévin.
> 
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Re: [Caml-list] Problem with location.

[Matt Gushee]

On Tue, Oct 26, 2004 at 09:36:10PM +0000, Tiago Dionizio wrote:
> You can try using:
> 
> #!/usr/bin/env ocamlrun
> 
> although i don't know how reliable this is, it should work.

Not 100% portable, I believe, but it should work on any Linux system,
and probably also *BSD and Solaris. This technique is commonly used in
the Python world.

-- 
Matt Gushee                 When a nation follows the Way,
Haven Rock Press            Horses bear manure through
Englewood, Colorado, USA        its fields;   
books@havenrock.com         When a nation ignores the Way,
                            Horses bear soldiers through
                                its streets.
                                
                            --Lao Tzu (Peter Merel, trans.)