Console.SetOut(TextWriter) Method

public:
 static void SetOut(System::IO::TextWriter ^ newOut);

public static void SetOut(System.IO.TextWriter newOut);

static member SetOut : System.IO.TextWriter -> unit

Public Shared Sub SetOut (newOut As TextWriter)

Parameters

Exceptions

Examples

The following example illustrates the use of the SetOut method. It replaces four consecutive space characters in a string with a tab character. To run it, you must supply two command line arguments. The first is the name of an existing text file to redirect the standard input stream to. The second is the name of a file to redirect the standard output stream to. This file need not exist. If it does, its contents will be overwritten.

using System;
using System.IO;

public class InsertTabs
{
 private const int tabSize = 4;
 private const string usageText = "Usage: INSERTTABS inputfile.txt outputfile.txt";
 public static int Main(string[] args)
 {
 if (args.Length < 2)
 {
 Console.WriteLine(usageText);
 return 1;
 }

 try
 {
 // Attempt to open output file.
 using (var writer = new StreamWriter(args[1]))
 {
 using (var reader = new StreamReader(args[0]))
 {
 // Redirect standard output from the console to the output file.
 Console.SetOut(writer);
 // Redirect standard input from the console to the input file.
 Console.SetIn(reader);
 string line;
 while ((line = Console.ReadLine()) != null)
 {
 string newLine = line.Replace(("").PadRight(tabSize, ' '), "\t");
 Console.WriteLine(newLine);
 }
 }
 }
 }
 catch(IOException e)
 {
 TextWriter errorWriter = Console.Error;
 errorWriter.WriteLine(e.Message);
 errorWriter.WriteLine(usageText);
 return 1;
 }

 // Recover the standard output stream so that a
 // completion message can be displayed.
 var standardOutput = new StreamWriter(Console.OpenStandardOutput());
 standardOutput.AutoFlush = true;
 Console.SetOut(standardOutput);
 Console.WriteLine($"INSERTTABS has completed the processing of {args[0]}.");
 return 0;
 }
}

open System
open System.IO

let tabSize = 4
let usageText = "Usage: INSERTTABS inputfile.txt outputfile.txt"

[<EntryPoint>]
let main args =
 if args.Length < 2 then
 Console.WriteLine usageText
 1
 else
 try
 // Attempt to open output file.
 use reader = new StreamReader(args[0])
 use writer = new StreamWriter(args[1])
 
 // Redirect standard output from the console to the output file.
 Console.SetOut writer
 
 // Redirect standard input from the console to the input file.
 Console.SetIn reader
 
 let mutable line = Console.ReadLine()
 while line <> null do
 let newLine = line.Replace(("").PadRight(tabSize, ' '), "\t")
 Console.WriteLine newLine
 line <- Console.ReadLine()

 // Recover the standard output stream so that a
 // completion message can be displayed.
 let standardOutput = new StreamWriter(Console.OpenStandardOutput())
 standardOutput.AutoFlush <- true
 Console.SetOut standardOutput
 Console.WriteLine $"INSERTTABS has completed the processing of {args[0]}."
 0

 with :? IOException as e -> 
 let errorWriter = Console.Error
 errorWriter.WriteLine e.Message
 errorWriter.WriteLine usageText
 1

Imports System.IO

Public Module InsertTabs
 Private Const tabSize As Integer = 4
 Private Const usageText As String = "Usage: INSERTTABS inputfile.txt outputfile.txt"
 
 Public Function Main(args As String()) As Integer
 If args.Length < 2 Then
 Console.WriteLine(usageText)
 Return 1
 End If
 
 Try
 ' Attempt to open output file.
 Using writer As New StreamWriter(args(1))
 Using reader As New StreamReader(args(0))
 ' Redirect standard output from the console to the output file.
 Console.SetOut(writer)
 ' Redirect standard input from the console to the input file.
 Console.SetIn(reader)
 Dim line As String = Console.ReadLine()
 While line IsNot Nothing
 Dim newLine As String = line.Replace("".PadRight(tabSize, " "c), ControlChars.Tab)
 Console.WriteLine(newLine)
 line = Console.ReadLine()
 End While
 End Using
 End Using
 Catch e As IOException
 Dim errorWriter As TextWriter = Console.Error
 errorWriter.WriteLine(e.Message)
 errorWriter.WriteLine(usageText)
 Return 1
 End Try

 ' Recover the standard output stream so that a 
 ' completion message can be displayed.
 Dim standardOutput As New StreamWriter(Console.OpenStandardOutput())
 standardOutput.AutoFlush = True
 Console.SetOut(standardOutput)
 Console.WriteLine($"INSERTTABS has completed the processing of {args(0)}.")
 Return 0
 End Function 
End Module

Remarks

By default, the Out property is set to the standard output stream.

A StreamWriter that encapsulates a FileStream can be used to send output to a file. For example:

Console.WriteLine("Hello World");
FileStream fs = new FileStream("Test.txt", FileMode.Create);
// First, save the standard output.
TextWriter tmp = Console.Out;
StreamWriter sw = new StreamWriter(fs);
Console.SetOut(sw);
Console.WriteLine("Hello file");
Console.SetOut(tmp);
Console.WriteLine("Hello World");
sw.Close();

Console.WriteLine "Hello World"
use fs = new FileStream("Test.txt", FileMode.Create)
// First, save the standard output.
let tmp = Console.Out
use sw = new StreamWriter(fs)
Console.SetOut sw
Console.WriteLine "Hello file"
Console.SetOut tmp
Console.WriteLine "Hello World"

Console.WriteLine("Hello World")
Dim fs As New FileStream("Test.txt", FileMode.Create)
' First, save the standard output.
Dim tmp as TextWriter = Console.Out
Dim sw As New StreamWriter(fs)
Console.SetOut(sw)
Console.WriteLine("Hello file")
Console.SetOut(tmp)
Console.WriteLine("Hello World")
sw.Close()

The actual object returned by Out may be a synchronized wrapper around the provided text writer.

See also

• TextWriter
• Out