ExecuteBufferedAsync - Access a merged Stdout and Sterror

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I'd love to be able to access a merged standard output and standard error on the BufferedCommandResult, as consuming the outputs separately has no way of maintaining ordering of logs. Ideally stdout and sterror are piped to the same pipe?

It could be done with something like

var result = await command.WithStandardErrorPipe(command.StandardOutputPipe).ExecuteBufferedAsync()

however this doesn't work currently

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[X] I have looked through existing issues to make sure that this feature has not been requested before
[X] I have provided a descriptive title for this issue
[X] I am aware that even valid feature requests may be rejected if they do not align with the project's goals
[ ] I have sponsored this project

The order cannot be guaranteed in the general case because those are two separate streams. If you run a program that produces and flushes output rapidly to both streams, you will see them come out of order every once in a while.

If you still want to do that, though, I wouldn't recommend merging outputs at the byte or character level, as that can potentially produce mangled results. You can instead initialize a list of strings and append new data only when a complete line has been flushed to any of the streams:

var lines = new List<string>();

await Cli.Wrap(...)
    .WithStandardOutputPipe(PipeTarget.ToDelegate(lines.Add))
    .WithStandardErrorPipe(PipeTarget.ToDelegate(lines.Add))
    .ExecuteAsync();

var mergedOutput = string.Join(Environment.NewLine, lines);

Because any approach to merge output is always going to be a best-effort attempt, and because the specifics of the underlying program and how it's wrapped may affect the desired behavior (for example, if you want real-time processing of merged output, the above solution is suboptimal), I decided to avoid implementing this as a first-party feature.

Tyrrrz / CliWrap

ExecuteBufferedAsync - Access a merged Stdout and Sterror #247

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