clsTempFile.cs

// C# ClassLib
// http://csharp-classlib.sourceforge.net
//
//
// Copyright (C) 2005 Marcel Joachim Kloubert
// 
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//

using System;
using System.IO;

namespace CSharp_ClassLib.Classes
{
        public class TempFile : System.Object
        {
                private string m_strTMPDirectory;
                private System.Random m_oRandom;
                private System.IO.FileStream m_oFileStream;     
                
                public TempFile()
                {
                        m_strTMPDirectory = "./";
                
                        this.InitRest();
                        
                        return;
                }
        
                public TempFile(string Temp_Directory)
                {
                        if (!System.IO.Directory.Exists(Temp_Directory))
                                // temp directory was not found!
                                throw ( new System.IO.DirectoryNotFoundException("The directory \"" + Temp_Directory + "\" was not found!") );
                
                        m_strTMPDirectory = this.TempDirectory;
                                
                        this.InitRest();
                        
                        return;
                }
                
                ~TempFile()
                {
                        string strFilename = this.Filestream.Name;
                
                        this.Filestream.Close();
                        
                        if ( System.IO.File.Exists(strFilename) )
                                // deletes the file if still exists
                                System.IO.File.Delete(strFilename);
                        
                        return;
                }

                private void InitRest ()
                {
                        m_oRandom = new System.Random( this.LongToInt(System.DateTime.Now.Ticks) );
                        
                        m_oFileStream = new System.IO.FileStream(this.TempDirectory + "/" + this.UniqueFilename, System.IO.FileMode.CreateNew, System.IO.FileAccess.ReadWrite, System.IO.FileShare.Read );

                        System.IO.File.SetAttributes(this.Filestream.Name, System.IO.FileAttributes.Hidden);
                
                        return;
                }
                
                public System.IO.FileStream Filestream
                {
                        get { return m_oFileStream; }
                }
                
                public string TempDirectory { get { return m_strTMPDirectory; } }
                
        
                private string UniqueFilename
                {
                        get
                        {
                                string strBuffer = "";
                                int i = 0;

                                const string cstrAlpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

                                while (true)
                                {
                                        // init random numbers & string buffer
                                        strBuffer = "";                 
                        
                                        // create first part
                                        for (i = 0; i < 8; i++)
                                                strBuffer += cstrAlpha.Substring( this.m_oRandom.Next(cstrAlpha.Length), 1 );
                        
                                        // add dot
                                        strBuffer += ".";
                        
                                        // create extension
                                        for (i = 0; i < 3; i++)
                                                strBuffer += cstrAlpha.Substring( this.m_oRandom.Next(cstrAlpha.Length), 1 );

                                        if ( !System.IO.File.Exists(this.m_strTMPDirectory + "/" + strBuffer) )
                                                // return generated filename only if not yet exists
                                                return strBuffer;
                                }
                        }
                }
                
                private int LongToInt (long Input)
                {
                        if ( Input > int.MaxValue )
                                return int.MaxValue;
                        else if ( Input < int.MinValue )
                                return int.MinValue;
                        else
                                return (int)Input;
                }
         }
}

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