File Copier - C# Programming Exercise

// Import the necessary namespaces for file handling
using System;
using System.IO;

class FileCopier
{
    // Main method where the program starts
    static void Main(string[] args)
    {
        // Check if the user has provided the correct number of arguments
        if (args.Length != 2)
        {
            Console.WriteLine("Usage: mycopy  ");
            return;
        }

        // Get the source and destination file paths from the command line arguments
        string sourceFile = args[0];
        string destinationFile = args[1];

        // Check if the source file exists
        if (!File.Exists(sourceFile))
        {
            Console.WriteLine("Error: The source file does not exist.");
            return;
        }

        // Check if the destination file already exists
        if (File.Exists(destinationFile))
        {
            Console.WriteLine("Warning: The destination file already exists. It will not be overwritten.");
            return;
        }

        try
        {
            // Open the source file for reading
            using (FileStream sourceStream = new FileStream(sourceFile, FileMode.Open, FileAccess.Read))
            {
                // Open the destination file for writing
                using (FileStream destStream = new FileStream(destinationFile, FileMode.Create, FileAccess.Write))
                {
                    // Set the block size to 512 KB
                    byte[] buffer = new byte[512 * 1024];  // 512 KB

                    int bytesRead;
                    // Read from the source file and write to the destination file in blocks of 512 KB
                    while ((bytesRead = sourceStream.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        destStream.Write(buffer, 0, bytesRead);
                    }

                    Console.WriteLine("File copied successfully.");
                }
            }
        }
        catch (Exception ex)
        {
            // Catch any errors that occur during file operations
            Console.WriteLine("An error occurred while copying the file: " + ex.Message);
        }
    }
}