# Write to and read from StdErr stream
# Write to standard error output using Console
var sourceFileName = "NonExistingFile";
try
{
System.IO.File.Copy(sourceFileName, "DestinationFile");
}
catch (Exception e)
{
var stdErr = Console.Error;
stdErr.WriteLine($"Failed to copy '{sourceFileName}': {e.Message}");
}
# Read from standard error of child process
var errors = new System.Text.StringBuilder();
var process = new Process
{
StartInfo = new ProcessStartInfo
{
RedirectStandardError = true,
FileName = "xcopy.exe",
Arguments = "\"NonExistingFile\" \"DestinationFile\"",
UseShellExecute = false
},
};
process.ErrorDataReceived += (s, e) => errors.AppendLine(e.Data);
process.Start();
process.BeginErrorReadLine();
process.WaitForExit();
if (errors.Length > 0) // something went wrong
System.Console.Error.WriteLine($"Child process error: \r\n {errors}");