AsyncCommand use main.stdout / main.stderr

[jakeheis]

Right now, AsyncCommand will always change the process's stdout and stderr to a Pipe (https://github.com/kareman/SwiftShell/blob/master/Sources/SwiftShell/Command.swift#L291).

There should be a way to start an AsyncCommand which still directs output to main.stdout and main.stderr. Simply forwarding the output using something like:

command.stdout.onOutput { $0.write(to: &stdout) }

is not sufficient, as pipes are block buffered but main.stdout is line buffered, so the command's output will not be written to stdout in the expected way.

I think this could potentially be solved by changing AsyncCommand.init to something like:

init(unlaunched process: Process, stdout: WritableStream? = nil, stderr: WritableStream? = nil)

[kareman]

Yes that would be useful. But AsyncCommand.init is not public, so we need to change the public api. Do you think the use case is common enough to warrant a new function runAsyncAndPrint, which returns a superclass of AsyncCommand without stdout and stderror?

[patchthecode]

Usually one use case is enough to constantly bite you in the ass i always say 😄. I like this library. I vote yes.

[kareman]

I’m about to do some refactoring of Command.swift to move anything Linux-specific to its own file. I will implement runAsyncAndPrint after that.

Does anyone have a better idea for the name? It is a bit wordy, but I think it fits in nicely with run, runAsync and runAndPrint.

Ideally this functionality should be implemented with an extra parameter on runAsync, but the return type needs to be different.

[kareman]

@jakeheis I implemented runAsyncAndPrint in branch 61-AsyncCommand_use_main.stdout.

[patchthecode]

will take pull.

[kareman]

Just released version 4.1 with this feature.