let cmp ?(skip1 = 0) fln1 ?(skip2 = 0) fln2 =
if (reduce fln1) = (reduce fln2) then
None
else if (test (And(Is_readable,Is_file)) fln1)
&& (test (And(Is_readable,Is_file)) fln2) then
let fd1 = open_in_bin fln1 in
let fd2 = open_in_bin fln2 in
let clean_fd () =
let () = try close_in fd1 with _ -> () in
let () = try close_in fd2 with _ -> () in
()
in
let test_empty st =
try
Stream.empty st;
true
with Stream.Failure ->
false
in
let _ = seek_in fd1 skip1 in
let _ = seek_in fd2 skip2 in
let stream1 = Stream.of_channel fd1 in
let stream2 = Stream.of_channel fd2 in
try
begin
while ((Stream.next stream1) = (Stream.next stream2)) do
()
done;
clean_fd ();
Some (Stream.count stream1)
end
with
| Stream.Failure ->
begin
match ((test_empty stream1),(test_empty stream2)) with
true, true ->
None
| true, false
| false, true
| false, false ->
clean_fd ();
Some (Stream.count stream1)
end
| e ->
clean_fd ();
raise e
else
(Some (-1))