dotnet/runtime

Process.StandardOutput.Peek() and Process.StandardError.Peek() hang until StreamReader receives data.

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#91.891 aberto em 11 de set. de 2023

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 (3 comments) (0 reactions) (0 assignees)C# (5.445 forks)batch import
area-System.Diagnostics.Processhelp wanted

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Description

Closing this issue because I cannot reproduce it reliably.

Originally posted by @jscarle in https://github.com/dotnet/runtime/issues/74677#issuecomment-1228951480

The original issue suggested to repro the problem using the Process.StandardOutput which is suboptimal because most of the processes we usually run produce some output. The issue shows itself only when output is empty. Just try the same but with the Process.StandardError. In most of the cases there will be no data in that stream and the issue will reproduce.

    var process = Process.Start(new ProcessStartInfo("path\to\executable.exe", arguments)
    {
        CreateNoWindow = true,
        UseShellExecute = false,
        RedirectStandardInput = true,
        RedirectStandardOutput = true,
        RedirectStandardError = true,
        StandardOutputEncoding = Encoding.UTF8,
        StandardErrorEncoding = Encoding.UTF8
    });

    var outputBuilder = new StringBuilder();
    while (process.StandardError.Peek() > -1)
        outputBuilder.Append((char)process.StandardError.Read());
    var result = outputBuilder.ToString();

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