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Treating arguments that start with `-' as anonymous arguments
- T. Kurt Bond
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| Date: | -- (:) |
| From: | T. Kurt Bond <tkb@a...> |
| Subject: | Treating arguments that start with `-' as anonymous arguments |
[I apologize for the lack of a French version of this message.]
When using the standard module Arg, I would sometimes like to be able
to define an keyword like the POSIX getopt keyword `--', which causes
all the rest of the command line arguments to be treated as anonymous
arguments. The following patch (against 1.07) adds to the Arg.spec
type a constructor, Arg.End, which allows the user to specify this.
For instance, if the following
let speclist = [
("-a", Arg.Unit (fun () -> prerr_endline "this was -a"), "a keyword");
("--", Arg.End, "Stop interpreting keywords")
] in
Arg.parse speclist (fun s -> prerr_endline ("anon arg: " ^ s))
"usage info goes here."
is compiled into a.out and run as follows
$ ./a.out -a anon -- -a
this was -a
anon arg: anon
anon arg: -a
the second -a gets treated as an anonymous argument.
--- arg.ml.orig Tue Jan 13 20:10:08 1998
+++ arg.ml Tue Jan 13 20:21:11 1998
@@ -18,6 +18,7 @@
| String of (string -> unit) (* Call the function with a string argument *)
| Int of (int -> unit) (* Call the function with an int argument *)
| Float of (float -> unit) (* Call the function with a float argument *)
+ | End (* Treat rest as anonymous arguments *)
exception Bad of string
@@ -42,6 +43,9 @@
;;
let current = ref 0;;
+(* True if checking options; False if rest of arguments are to be interpeted
+ as anonymous arguments. *)
+let checking_opts = ref true;;
let parse speclist anonfun errmsg =
let initpos = !current in
@@ -67,7 +71,7 @@
incr current;
while !current < l do
let s = Sys.argv.(!current) in
- if String.length s >= 1 & String.get s 0 = '-' then begin
+ if !checking_opts & String.length s >= 1 & String.get s 0 = '-' then begin
let action =
try assoc3 s speclist
with Not_found -> stop (Unknown s)
@@ -91,6 +95,7 @@
let arg = Sys.argv.(!current+1) in
f (float_of_string arg);
incr current;
+ | End -> checking_opts := false;
| _ -> stop (Missing s)
with Bad m -> stop (Message m);
end;
--- arg.mli.orig Tue Jan 13 20:10:09 1998
+++ arg.mli Tue Jan 13 20:21:34 1998
@@ -42,6 +42,7 @@
| String of (string -> unit) (* Call the function with a string argument *)
| Int of (int -> unit) (* Call the function with an int argument *)
| Float of (float -> unit) (* Call the function with a float argument *)
+ | End (* Treat rest as anonymous arguments *)
(* The concrete type describing the behavior associated
with a keyword. *)
--
T. Kurt Bond, tkb@access.mountain.net