3dz Soft

I recently encountered a situation where I needed to copy some files over a location where files with the same name already existed, and overwriting them wasn’t an option. So, the following code snippet verifies if a file with the same name already exists, in case which it tries to put a number after the file’s name.

public static void FileCopyWithoutOverwriting(string sourceFile, string fileName, string destinationPath)
        {
            // if destinationPath doesn't add with a slash, add one
            if ((destinationPath.EndsWith("\\") || destinationPath.EndsWith("/")) == false)
                destinationPath  += "\\";

            try
            {
                // if file already exists in destination
                if (File.Exists(destinationPath + fileName))
                {
                    // counter
                    int count = 1;

                    // extract extension
                    FileInfo info = new FileInfo(sourceFile);
                    string ext = info.Extension;
                    string prefix;

                    // if it has an extension, append it to a .
                    if (ext.Length > 0)
                    {
                        // get filename without extension
                        prefix = fileName.Substring(0, fileName.Length - ext.Length);
                        ext = "." + ext;
                    }
                    else
                        prefix = fileName;

                    // while not found an valid destination file name, increase counter
                    while (File.Exists(destinationPath + fileName))
                    {
                        fileName = prefix + "(" + count.ToString() + ")" + ext;
                        count++;
                    }
                    // copy file
                    File.Copy(sourceFile, destinationPath + fileName);
                }
                else
                {
                    File.Copy(sourceFile, destinationPath + fileName);
                }
                Console.WriteLine("File copy done.");
            }
            catch (UnauthorizedAccessException)
            {
                Console.WriteLine("The caller does not have the required permission.");
            }
            catch (ArgumentException)
            {
                Console.WriteLine("One of the arguments is invalid.");
            }
            catch (PathTooLongException)
            {
                Console.WriteLine("The specified path, file name, or both exceed the system-defined maximum length.");
            }
            catch (DirectoryNotFoundException)
            {
                Console.WriteLine("At least one of the specified paths are invalid.");
            }
            catch (FileNotFoundException)
            {
                Console.WriteLine("{0} was not found", sourceFile);
            }
            catch (IOException)
            {
                Console.WriteLine("An I/O error has occurred.");
            }
            catch (NotSupportedException)
            {
                Console.WriteLine("Source filename is in invalid format.");
            }
        }

I hope that you’ll find this helpful

UPDATE: A made a better version, with exception  handling too.