Please provide a way to set untranslated I/O mode on Windows

[projektorius96]

So I am writing a Native messaging host for Chromium-based browser in Dart, I have a working draft of transcoding implementation and it works for decodeMessage (at least I can see that on my side with stdout redirected to file), but it seems that it breaks on dart_io.stdout.write call, and not because of encodeMessage implementation itself, but due to default (i.e. _O_TEXT) Windows's I/O translation mode, which in turn corrupts the encoded message with the respond from Chromium-based browser Extension system Error when communicating with the native messaging host.

I am writing this to to request a feature, which as far as I do understand does not currently (2024 Q1) exist on higher level end of Dart VM, i.e. to control the I/O mode for Windows via Dart VM . Please understand that FFI to C via Win API is my last resort.

P.S. I am willing to share the final codebase with Dart community once I get it done working

Thank you.

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This tracker is for issues related to:

• Dart core libraries
• Dart native compilers
• Dart VM

[projektorius96]

Windows users only!

Consider the following alternative instead of Native Messaging Host – the motivation of using this, could be a simpler set up and no registry involved.

Cheers ! ♥

[brianquinlan]

@projektorius96 I don't understand your issue; stdout.write does not do new line translation by default (in Dart 3.4, you will be able to control that behavior with the lineTerminator field.

Do you have a minimal example that demonstrates the issue?

[projektorius96]

@projektorius96 I don't understand your issue; stdout.write does not do new line translation by default (in Dart 3.4, you will be able to control that behavior with the lineTerminator field.

Do you have a minimal example that demonstrates the issue?

Well, first of all REAMDE.md provides a quick insight how to do repro on local machine, well I guess you know better than me how to glue up things for sure.

To follow up, I have couple of arbitrarily defined functions as per implementation :

• decodeMessage works just fine, stream redirection to file shows exactly same message sent from service-worker via sendNativeMessage source
• encodeMessage somehow corrupts a message and I naturally suspected the I/O translation mode keeping in mind it is documented in Debugging as described per original post; After all, it can be something wrong with encodeMessage itself, but in that case, I'd say Chromium is really nit-picky if it cannot pick up even broken message, rather than giving me the aforementioned error as follows "Error when communicating with the native messaging host." .

Finally, I just wanted to say it is my very first try doing something relatively low, but in higher programming language, and I even fail at that. It simply can be something wrong with my codebase due to lack of knowledge. However, I wrote an alternative solution based on WebSocket to communicate between the Dart host and Service Worker, I'd say I even prefer the later one, yet I was interested into implementing former one too. Curiosity is a powerful weapon, but like I said I am failing with native messaging host at this stage.

Cheers !

[brianquinlan]

Hi @projektorius96

I'm going to close this issue. If you manage to reduce this enough to demonstrate a bug in dart:io, please reopen it!

[projektorius96]

@brianquinlan so apparently I have to admit I was wrong, I mean well like I said "lack of knowledge", if you ever eyeballed on my codebase, you perhaps you had said that I need to await stdout.flush(), but nah it took me couple of yours to figure out it by myself, perhaps ill-service would not serve me for better as developer, yet I was expecting a bit of the help out here and got none. Crocodile tears 🤔

[projektorius96]

If interested, you can follow up the related discussion on this issue. I am closing this myself, if you have anything to add, please re-open.

Cheers !