Demonstrates opening/creating a file for writing and truncating its length to 0 bytes.
/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa
Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
// StrmWrit.cs -- Demonstrates opening/creating a file for writing and truncating
// its length to 0 bytes.
// Compile this program with the following command line:
// C:>csc StrmWrit.cs
using System;
using System.IO;
namespace nsStreams
{
public class StrmWrit
{
static public void Main ()
{
FileStream strm;
// Open or create the file for writing
try
{
strm = new FileStream ("./write.txt", FileMode.OpenOrCreate, FileAccess.Write);
}
// If the open fails, the constructor will throw an exception.
catch (Exception e)
{
Console.WriteLine (e.Message);
Console.WriteLine ("Cannot open write.txt for writing");
return;
}
// Truncate the file using the SetLength() method.
strm.SetLength (0);
Console.WriteLine ("Enter text. Type a blank line to exit\r\n");
// Accept text from the keyboard and write it to the file.
while (true)
{
string str = Console.ReadLine ();
if (str.Length == 0)
break;
byte [] b; // = new byte [str.Length];
StringToByte (str, out b);
strm.Write (b, 0, b.Length);
}
Console.WriteLine ("Text written to write.txt");
// Close the stream
strm.Close ();
}
//
// Convert a string to a byte array, adding a carriage return/line feed to it
static protected void StringToByte (string str, out byte [] b)
{
b = new byte [str.Length + 2];
int x;
for (x = 0; x < str.Length; ++x)
{
b[x] = (byte) str[x];
}
// Add a carriage return/line feed
b[x] = 13;
b[x + 1] = 10;
}
}
}
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