How do I capture command-line text that is not sent to stdout?

问题

I am using the LAME command line mp3 encoder in a project. I want to be able to see what version someone is using. if I just execute LAME.exe with no paramaters i get, for example:

C:\LAME>LAME.exe
LAME 32-bits version 3.98.2 (http://www.mp3dev.org/)

usage: blah blah
blah blah

C:\LAME>

if i try redirecting the output to a text file using > to a text file the text file is empty. Where is this text accessable from when running it using System.Process in c#?

回答1:

It's probably using stderr. cmd.exe doesn't allow you to redirect stderr, and the only way I've ever redirected it is with a djgpp tool.

回答2:

It may be output to stderr instead of stdout. You can redirect stderr by doing:

LAME.exe 2> textfile.txt

If this shows you information, then LAME is outputting to the standard error stream. If you write a wrapper in C#, you can redirect the standard error and output streams from ProcessStartInfo.

回答3:

        System.Diagnostics.Process proc = new System.Diagnostics.Process();
        proc.EnableRaisingEvents = false;
        proc.StartInfo.FileName = @"C:\LAME\LAME.exe";
        proc.StartInfo.RedirectStandardError = true;
        proc.StartInfo.UseShellExecute = false;

        proc.Start();
        string output = proc.StandardError.ReadToEnd();


        proc.WaitForExit();

        MessageBox.Show(output);

worked. thanks all!

回答4:

It might be sent to stderr, have you tried that?

Check out Process.StandardError.

Try it out using

C:\LAME>LAME.exe 2> test.txt

来源：https://stackoverflow.com/questions/2208900/how-do-i-capture-command-line-text-that-is-not-sent-to-stdout