Revisited: .NET/C# – TEE filter that also runs on Windows (XP) Embedded « The Wiert Corner – irregular stream of Wiert stuff
Posted by jpluimers on 2011/08/16
More than a year ago, I wrote about .NET/C# – TEE filter that also runs on Windows (XP) Embedded.
Since then, I have made two changes to the code (which is below and in this CodePlex changeset):
- using file modes FileAccess.Write and FileShare.Read, which allows you to load the output files with tools opening them in a read-only, deny none mode
- optional flush of the files every CRLF pair, or every 4096 bytes
using System;
using System.IO;
using System.Collections.Generic;
// Sends standard input to standard output and to all files in command line.
// C# implementation april 4th, 2010 by Jeroen Wiert Pluimers (https://wiert.wordpress.com),
// based on tee Chip Camden, Camden Software Consulting, November 2005
// ... and Anonymous Cowards everywhere!
//
// TEE [-a | --append] [-i | --ignore] [--help | /?] [-f] [file1] [...]
// Example:
// tee --append file0.txt -f --help file2.txt
// will append to file0.txt, --help, and file2.txt
//
// -a | --append Appends files instead of overwriting
// (setting is per tee instance)
// -f | --flush Flushes files every CRLF or every 4096 bytes
// (setting is per tee instance)
// -i | --ignore Ignore cancel Ctrl+C keypress: see UnixUtils tee
// /? | --help Displays this message and immediately quits
// -f Stop recognizing flags, force all following filenames literally
//
// Duplicate filenames are quietly ignored.
// Press Ctrl+Z (End of File character) then Enter to abort.
namespace Tee
{
class Program
{
static void help()
{
Console.Error.WriteLine("Sends standard input to standard output and to all files in command line.");
Console.Error.WriteLine("C# implementation april 4th, 2010 by Jeroen Wiert Pluimers (https://wiert.wordpress.com),");
Console.Error.WriteLine("Chip Camden, Camden Software Consulting, November 2005");
Console.Error.WriteLine(" ... and Anonymous Cowards everywhere!");
Console.Error.WriteLine("http://www.camdensoftware.com");
Console.Error.WriteLine("http://chipstips.com/?tag=cpptee");
Console.Error.WriteLine("");
Console.Error.WriteLine("tee [-a | --append] [-i | --ignore] [--help | /?] [-f] [file1] [...]");
Console.Error.WriteLine(" Example:");
Console.Error.WriteLine(" tee --append file0.txt -f --help file2.txt");
Console.Error.WriteLine(" will append to file0.txt, --help, and file2.txt");
Console.Error.WriteLine("");
Console.Error.WriteLine("-a | --append Appends files instead of overwriting");
Console.Error.WriteLine(" (setting is per tee instance)");
Console.Error.WriteLine("-f | --flush Flushes files every CRLF or every 4096 bytes");
Console.Error.WriteLine(" (setting is per tee instance)");
Console.Error.WriteLine("-i | --ignore Ignore cancel Ctrl+C keypress: see UnixUtils tee");
Console.Error.WriteLine("/? | --help Displays this message and immediately quits");
Console.Error.WriteLine("-f Stop recognizing flags, force all following filenames literally");
Console.Error.WriteLine("");
Console.Error.WriteLine("Duplicate filenames are quietly ignored.");
Console.Error.WriteLine("Press Ctrl+Z (End of File character) then Enter to abort.");
}
static void OnCancelKeyPressed(Object sender, ConsoleCancelEventArgs args)
{
// Set the Cancel property to true to prevent the process from
// terminating.
args.Cancel = true;
}
static List filenames = new List();
static void addFilename(string value)
{
if (-1 == filenames.IndexOf(value))
filenames.Add(value);
}
static int Main(string[] args)
{
try
{
bool appendToFiles = false;
bool flushFiles = false;
bool stopInterpretingFlags = false;
bool ignoreCtrlC = false;
foreach (string arg in args)
{
//Since we're already parsing.... might as well check for flags:
if (stopInterpretingFlags) //Stop interpreting flags, assume is filename
{
addFilename(arg);
}
else if (arg.Equals("/?") || arg.Equals("-h") || arg.Equals("--help"))
{
help();
return 1; //Quit immediately
}
else if (arg.Equals("-a") || arg.Equals("--append"))
{
appendToFiles = true;
}
else if (arg.Equals("-f") || arg.Equals("--flush"))
{
flushFiles = true;
}
else if (arg.Equals("-i") || arg.Equals("--ignore"))
{
ignoreCtrlC = true;
}
else if (arg.Equals("-f"))
{
stopInterpretingFlags = true;
}
else
{ //If it isn't any of the above, it's a filename
addFilename(arg);
}
//Add more flags as necessary, just remember to SKIP adding them to the file processing stream!
}
if (ignoreCtrlC) //Implement the Ctrl+C fix selectively (mirror UnixUtils tee behavior)
Console.CancelKeyPress += new ConsoleCancelEventHandler(OnCancelKeyPressed);
List binaryWriters = new List(filenames.Count); //Add only as many streams as there are distinct files
try
{
foreach (String filename in filenames)
{
FileStream fileStream = new FileStream(filename,
appendToFiles ? FileMode.Create : FileMode.OpenOrCreate,
FileAccess.Write,
FileShare.Read);
/* appendToFiles ?
File.AppendText(filename).BaseStream :
File.Create(filename)
*/
binaryWriters.Add(new BinaryWriter(fileStream)); // Open the files specified as arguments
}
using (BinaryReader stdin = new BinaryReader(Console.OpenStandardInput()))
{
using (BinaryWriter stdout = new BinaryWriter(Console.OpenStandardOutput()))
{
Byte b;
Byte previous = 0;
Int64 index = 0;
while (true)
{
try
{
b = stdin.ReadByte(); // Read standard in
}
catch (EndOfStreamException)
{
break;
}
// The actual tee:
stdout.Write(b); // Write standard out
bool isCRLF = (previous == 13) && (b == 10);
previous = b;
foreach (BinaryWriter binaryWriter in binaryWriters)
{
binaryWriter.Write(b); // Write to each file
index++;
if (flushFiles)
if ((isCRLF) || (0 == index % 4096))
binaryWriter.Flush();
}
}
}
}
}
finally
{
foreach (BinaryWriter binaryWriter in binaryWriters)
{
binaryWriter.Flush(); // Flush and close each file
binaryWriter.Close();
}
}
}
catch (Exception ex)
{
Console.Error.WriteLine(String.Concat("tee: ", ex.Message)); // Send error messages to stderr
}
return 0;
}
}
}
The Wiert Corner - irregular stream of stuff 
C# text file deduping based on trimmed lines (via: Stack Overflow) « The Wiert Corner – irregular stream of Wiert stuff said
[…] based my code on the C# Tee filter and the StackOverflow example of C# deduping based on […]
Power Flusher said
powerflush500…
[…]Revisited: .NET/C# – TEE filter that also runs on Windows (XP) Embedded « The Wiert Corner – irregular stream of Wiert stuff « The Wiert Corner – irregular stream of Wiert stuff[…]…