Question

Like the title suggests, is there an equivalent to Process.Start (allows you run another application or batch file) that I can await?

I’m playing with a small console app and this seemed like the perfect place to be using async and await but I can’t find any documentation for this scenario.

What I’m thinking is something along these lines:

void async RunCommand()
{
    var result = await Process.RunAsync("command to run");
}

Answer 1

Process.Start() only starts the process, it doesn’t wait until it finishes, so it doesn’t make much sense to make it async. If you still want to do it, you can do something like await Task.Run(() => Process.Start(fileName)).

But, if you want to asynchronously wait for the process to finish, you can use the Exited event together with TaskCompletionSource:

static Task<int> RunProcessAsync(string fileName)
{
    var tcs = new TaskCompletionSource<int>();

    var process = new Process
    {
        StartInfo = { FileName = fileName },
        EnableRaisingEvents = true
    };

    process.Exited += (sender, args) =>
    {
        tcs.SetResult(process.ExitCode);
        process.Dispose();
    };

    process.Start();

    return tcs.Task;
}