Csharp/C Sharp/File Stream/FileStream

An enhanced cipher component that maintains a log file

<source lang="csharp"> /* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852

• /

// An enhanced cipher component that maintains a log file. using CipherLib; // import CipherComp"s namespace

using System; using System.ruponentModel; using System.IO;

namespace CipherLib {

 // An Cipher component that maintains a log file. 
 class CipherComp : Component {   
   static int useID = 0; 
   int id; // instance id 
   bool isDisposed; // true if component is disposed.  
   FileStream log; 
 
   // Constructor  
   public CipherComp() {  
     isDisposed = false; // component not disposed  
     try {  
       log = new FileStream("CipherLog" + useID, FileMode.Create);  
       id = useID; 
       useID++; 
     } catch (FileNotFoundException exc) {  
       Console.WriteLine(exc);  
       log = null; 
     }  
   }  

   // Destructor  
   ~CipherComp() {  
      Console.WriteLine("Destructor for component " 
                        + id); 
      Dispose(false);  
   }  
 
   // Encode the file. Return and store result. 
   public string Encode(string msg) {  
 
     string temp = "";  
 
     for(int i=0;i < msg.Length; i++)   
       temp += (char) (msg[i] + 1);          
 
     // Store in log file.  
     for(int i=0; i < temp.Length; i++)  
       log.WriteByte((byte) temp[i]);  
 
     return temp; 
   }  
 
   // Decode the message. Return and store result.  
   public string Decode(string msg) {  
 
     string temp = "";  
 
     for(int i=0; i < msg.Length; i++)  
       temp += (char) (msg[i] - 1);  
 
     // Store in log file.  
     for(int i=0; i < temp.Length; i++)  
       log.WriteByte((byte) temp[i]);  

     return temp; 
   }  
 
   protected override void Dispose(bool dispAll) {  
     Console.WriteLine("Dispose(" + dispAll + 
                       ") for component " + id); 

     if(!isDisposed) {  
       if(dispAll) {  
         Console.WriteLine("Closing file for " + 
                           "component " + id); 
         log.Close(); // close encoded file  
         isDisposed = true;  
       }  
       // no unmanaged resources to release  
       base.Dispose(dispAll);  
     }  
   }  
 }  

} // Another client that uses CipherComp.

public class CipherCompClient1 {

 public static void Main() {  
   CipherComp cc = new CipherComp();  
 
   string text = "Testing";  
 
   string ciphertext = cc.Encode(text);  
   Console.WriteLine(ciphertext);  
 
   string plaintext = cc.Decode(ciphertext);  
   Console.WriteLine(plaintext);  

   text = "Components are powerful."; 

   ciphertext = cc.Encode(text);  
   Console.WriteLine(ciphertext);  
 
   plaintext = cc.Decode(ciphertext);  
   Console.WriteLine(plaintext);  
 
   cc.Dispose(); // free resources  
 }  

}

      </source>

A simple disk-to-screen utility that demonstrates a FileReader

<source lang="csharp"> /* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852

• /

/* A simple disk-to-screen utility that

  demonstrates a FileReader. */ 

using System; using System.IO;

public class DtoS {

 public static void Main() { 
   FileStream fin; 
   string s; 

   try { 
     fin = new FileStream("test.txt", FileMode.Open); 
   } 
   catch(FileNotFoundException exc) { 
     Console.WriteLine(exc.Message + "Cannot open file."); 
     return ; 
   }  

   StreamReader fstr_in = new StreamReader(fin); 

   // Read the file line-by-line. 
   while((s = fstr_in.ReadLine()) != null) { 
     Console.WriteLine(s); 
   } 

   fstr_in.Close(); 
 } 

}

      </source>

Compare two files

<source lang="csharp"> /* C# A Beginner"s Guide By Schildt Publisher: Osborne McGraw-Hill ISBN: 0072133295

• /

/*

  Project 11-1 

  Compare two files. 

  To use this program, specify the names   
  of the files to be compared on the command line. 

  For example: 
      CompFile FIRST.TXT SECOND.TXT  

• /

using System; using System.IO;

public class CompFiles {

 public static void Main(string[] args) {  
   int i=0, j=0;  
   FileStream f1;  
   FileStream f2;  
 
   try {  
     // open first file 
     try {  
       f1 = new FileStream(args[0], FileMode.Open);  
     } catch(FileNotFoundException exc) {  
       Console.WriteLine(exc.Message);  
       return;  
     }  
 
     // open second file  
     try {  
       f2 = new FileStream(args[1], FileMode.Open);  
     } catch(FileNotFoundException exc) {  
       Console.WriteLine(exc.Message);  
       return;  
     }  
   } catch(IndexOutOfRangeException exc) {  
     Console.WriteLine(exc.Message + "\nUsage: CompFile f1 f2");  
     return;  
   }  
 
   // Compare files  
   try {  
     do {  
       i = f1.ReadByte();  
       j = f2.ReadByte();  
       if(i != j) break; 
     } while(i != -1 && j != -1);  
   } catch(IOException exc) {  
     Console.WriteLine(exc.Message);  
   }  
   if(i != j)  
     Console.WriteLine("Files differ."); 
   else 
     Console.WriteLine("Files are the same."); 
 
   f1.Close();  
   f2.Close();  
 }  

}

      </source>

Create a file stream with new FileStream("test.bin", FileMode.Create)

<source lang="csharp"> using System; using System.IO; class MainClass {

   static void Main() {
       using (FileStream fs = new FileStream("test.bin", FileMode.Create)) {
           using (BinaryWriter w = new BinaryWriter(fs)) {
               w.Write(124.23M);
               w.Write("Tstring");
               w.Write("Tstring 2");
               w.Write("!");
           }
       }
       Console.WriteLine("Press Enter to read the information.");
       Console.ReadLine();
       using (FileStream fs = new FileStream("test.bin", FileMode.Open)) {
           using (StreamReader sr = new StreamReader(fs)) {
               Console.WriteLine(sr.ReadToEnd());
               Console.WriteLine();
               fs.Position = 0;
               using (BinaryReader br = new BinaryReader(fs)) {
                   Console.WriteLine(br.ReadDecimal());
                   Console.WriteLine(br.ReadString());
                   Console.WriteLine(br.ReadString());
                   Console.WriteLine(br.ReadChar());
               }
           }
       }
   }

}

</source>

Create StreamReader from File Stream

<source lang="csharp"> using System; using System.IO; public class IOExample {

 static void Main() {   
   FileStream fs;
   StreamReader srIn;
   try {
     fs = new FileStream("practice.txt", FileMode.Open );
     srIn = new StreamReader(fs);
     string line = srIn.ReadLine();
     Console.WriteLine("line = "+line);
     srIn.Close();
   } catch (IOException ioe) {
     Console.WriteLine("IOException occurred: "+ioe.Message);
   }
 }

}

      </source>

FileStream with FileMode.Create and FileMode.Open

<source lang="csharp"> using System; using System.IO; using System.Text; class MainClass {

   static void Main() {
       using (FileStream fs = new FileStream("test.txt", FileMode.Create)) {
           using (StreamWriter w = new StreamWriter(fs, Encoding.UTF8)) {
               w.WriteLine(124.23M);
               w.WriteLine("Test string");
               w.WriteLine("!");
           }
       }
       Console.WriteLine("Press Enter to read the information.");
       Console.ReadLine();
       // Open the file in read-only mode.
       using (FileStream fs = new FileStream("test.txt", FileMode.Open)) {
           using (StreamReader r = new StreamReader(fs, Encoding.UTF8)) {
               // Read the data and convert it to the appropriate data type.
               Console.WriteLine(Decimal.Parse(r.ReadLine()));
               Console.WriteLine(r.ReadLine());
               Console.WriteLine(Char.Parse(r.ReadLine()));
           }
       }
   }

}

      </source>

illustrates reading and writing binary data

<source lang="csharp"> /* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110

• /

/*
 Example15_15.cs illustrates reading and writing binary data

• /

using System; using System.IO; public class Example15_15 {

 public static void Main() 
 {
   // create a new file to work with
   FileStream outStream = File.Create("c:\\BinaryTest.dat");
   // use a BinaryWriter to write formatted data to the file
   BinaryWriter bw = new BinaryWriter(outStream);
   // write various data to the file
   bw.Write( (int) 32);
   bw.Write( (decimal) 4.567);
   string s = "Test String";
   bw.Write(s);
   // flush and close
   bw.Flush();
   bw.Close();
   // now open the file for reading
   FileStream inStream = File.OpenRead("c:\\BinaryTest.dat");
   // use a BinaryReader to read formatted data and dump it to the screen
   BinaryReader br = new BinaryReader(inStream);
   int i = br.ReadInt32();
   decimal d = br.ReadDecimal();
   string s2 = br.ReadString();
   Console.WriteLine(i);
   Console.WriteLine(d);
   Console.WriteLine(s2);
   // clean up
   br.Close();
 }

}

      </source>

illustrates use of FileStreams

<source lang="csharp"> /* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110

• /

/*
 Example15_10.cs illustrates use of FileStreams

• /

using System; using System.Windows.Forms; using System.IO; public class Example15_10 {

   [STAThread]
 public static void Main() 
 {
   // use an open file dialog to get a filename
   OpenFileDialog dlgOpen = new OpenFileDialog();
   dlgOpen.Title="Select file to back up";
   if (dlgOpen.ShowDialog() == DialogResult.OK)
   {
     FileStream inStream = File.OpenRead(dlgOpen.FileName);
     FileStream outStream = 
      File.OpenWrite(dlgOpen.FileName + ".bak");
     int b;
     // copy all data from in to out
     while ((b = inStream.ReadByte()) > -1)
       outStream.WriteByte( (byte) b);
     // clean up
     outStream.Flush();
     outStream.Close();
     inStream.Close();
   }
 }

}

      </source>

illustrates use of FileStreams 2

<source lang="csharp"> /* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110

• /

/*
 Example15_11.cs illustrates use of FileStreams

• /

using System; using System.Windows.Forms; using System.IO; public class Example15_11 {

   [STAThread]
 public static void Main() 
 {
   // use an open file dialog to get a filename
   OpenFileDialog dlgOpen = new OpenFileDialog();
   dlgOpen.Title="Select file to back up";
   if (dlgOpen.ShowDialog() == DialogResult.OK)
   {
     FileStream inStream = File.OpenRead(dlgOpen.FileName);
     FileStream outStream = 
       File.OpenWrite(dlgOpen.FileName + ".bak");
     byte[] buf = new byte[4096];
     int bytesRead;
     // copy all data from in to out
     while ((bytesRead = inStream.Read(buf, 0, 4096)) > 0)
       outStream.Write(buf, 0, bytesRead);
     // clean up
     outStream.Flush();
     outStream.Close();
     inStream.Close();
   }
 }

}

      </source>

Reading and Writing Files

<source lang="csharp"> using System; using System.IO; public class ReadingWritingFiles {

   public static void Main()
   {
       FileStream f = new FileStream("output.txt", FileMode.Create);
       StreamWriter s = new StreamWriter(f);
       
       s.WriteLine("{0} {1}", "test", 55);
       s.Close();
       f.Close();
   }

}

      </source>

Reads lines separated by vertical bars

<source lang="csharp"> using System; using System.IO; public class FileReadAddresses {

 public static void Main( ) {
   String line;
   String street, city, state, zip;
   StreamReader f = new StreamReader("test.data");
   while ((line=f.ReadLine())!= null){
     String[] strings = line.Split(new char[]{"|"});
     if (strings.Length == 4) {
       street = strings[0];
       city = strings[1];
       state = strings[2];
       zip = strings[3];
       Console.WriteLine(street); 
       Console.WriteLine(city);
       Console.WriteLine(state);
       Console.WriteLine(zip);
     }
   }
   f.Close();
 }

} //File: test.data /* 4665 Street|Toronto|ON|90048

• /

      </source>

Reads strings from a file created in a text editor

<source lang="csharp"> using System; using System.IO; public class FileReadStrings {

 public static void Main( ) {
   String line;
   StreamReader f = new StreamReader("test.data");        
   while((line=f.ReadLine()) != null)                           
     Console.WriteLine(line);
   f.Close(); 
 }

} //File: test.data /* 4665 Street|Toronto|ON|90048

• /

      </source>

Seek from Begin

<source lang="csharp">

using System; using System.Collections.Generic; using System.Text; using System.IO;

class Program {

   static void Main(string[] args) {
       byte[] byData = new byte[200];
       char[] charData = new Char[200];
       try {
           FileStream aFile = new FileStream("Program.cs", FileMode.Open);
           aFile.Seek(135, SeekOrigin.Begin);
           aFile.Read(byData, 0, 200);
       } catch (IOException e) {
           Console.WriteLine("An IO exception has been thrown!");
           Console.WriteLine(e.ToString());
           Console.ReadKey();
           return;
       }
       Decoder d = Encoding.UTF8.GetDecoder();
       d.GetChars(byData, 0, byData.Length, charData, 0);
       Console.WriteLine(charData);
   }

}

</source>

Set File IO Permission to c:

<source lang="csharp"> using System; using System.Collections.Generic; using System.Text; using System.Security.Permissions;

class Program {

   static void Main(string[] args) {
       MyClass.Method();
   }

} [FileIOPermission(SecurityAction.Assert, Read = "C:/")] class MyClass {

   public static void Method() {
       // implementation goes here
   }

}

      </source>

Using FileStreams

<source lang="csharp"> /*

* C# Programmers Pocket Consultant
* Author: Gregory S. MacBeth
* Email: gmacbeth@comporium.net
* Create Date: June 27, 2003
* Last Modified Date:
* Version: 1
*/

using System; using System.IO; namespace Client.Chapter_11___File_and_Streams {

 public class UsingFileStreams {
   static void Main(string[] args)
   {
     //Creates a file with read-write access that allows others to read
     FileStream MyFileStream1 = new FileStream(@"c:\Projects\Testing.txt", FileMode.Create);
     FileInfo MyFiles = new FileInfo(@"c:\Projects\Testing.txt");
     FileStream MyFileStream2 = MyFiles.OpenRead();
     //or any of the following
     MyFileStream2 = MyFiles.OpenWrite();
     MyFileStream2 = MyFiles.Open(FileMode.Append, FileAccess.Read, FileShare.None);
     MyFileStream2 = MyFiles.Create();
     //You can read file stream ona pe byte basis or as an array of bytes
     int MyBytes = MyFileStream1.ReadByte();
     //or
     int NumberOfBytes = 200;
     byte[] MyByteArray = new Byte[NumberOfBytes];
     int BytesRead = MyFileStream1.Read(MyByteArray, 0, NumberOfBytes);
     //Data can be written to FileStreams as well through bytes or arrays of //bytes
     byte MyWriteByte = 100;
     MyFileStream1.WriteByte(MyWriteByte);
     //or via an array
     int NumberOfBytesToWrite = 256;
     byte[] MyWriteByteArray = new Byte[NumberOfBytesToWrite];
     for (int i = 0; i < 256; i++)
     {
       MyWriteByteArray[i] = (byte)i;
       i++;
     }
     MyFileStream1.Write(MyWriteByteArray, 0, NumberOfBytesToWrite);
     MyFileStream1.Close();
     MyFileStream2.Close();
   }
 }

}

      </source>

Write byte array to a file

<source lang="csharp">

using System; using System.Collections.Generic; using System.Text; using System.IO; class Program {

   static void Main(string[] args) {
       byte[] byData;
       char[] charData;
       try {
           FileStream aFile = new FileStream("Temp.txt", FileMode.Create);
           charData = "www.nfex.ru".ToCharArray();
           byData = new byte[charData.Length];
           Encoder e = Encoding.UTF8.GetEncoder();
           e.GetBytes(charData, 0, charData.Length, byData, 0, true);
           aFile.Seek(0, SeekOrigin.Begin);
           aFile.Write(byData, 0, byData.Length);
       } catch (IOException ex) {
           Console.WriteLine(ex.ToString());
           return;
       }
   }

}

</source>