c# copying files from source folder to target folder

Question

Source and Target have the same subdirectories like this :

c:\fs\source\a\
c:\fs\source\b\

c:\fs\target\a\
c:\fs\target\b\

I am battling with copying files from source to target if not existing files. What is the best way in C# to compare source folders with target folders - check if target files dont exit, copy files from a specific source (c:\fs\source\a\config.xml and app.config) to a specific target (c:\fs\target\a\). If target files exist, ignore it. How to write it in C#?

Your code example very much appreciated. Thanks!

    public void TargetFileCreate()
    {
        foreach (var folder in SourceFolders)
        {
            string[] _sourceFileEntries = Directory.GetFiles(folder);

            foreach (var fileName in _sourceFileEntries)
            {    //dont know how to implement here:
                 //how to compare source file to target file to check if files exist or not
                 //c:\fs\source\A\config.xml compares to c:\fs\target\A\ (no files) that should be pasted
                 //c:\fs\source\B\config.xml compares to c:\fs\target\B\config.xml that is already existed - no paste
            }
        }
    }

Answer 1

You can check for each file if it exists this way:

string curFile = @"c:\temp\test.txt";
Console.WriteLine(File.Exists(curFile) ? "File exists." : "File does not exist.");

put this inside your loop. then copy those files there.

MSDN CODE:

// Simple synchronous file copy operations with no user interface. 
// To run this sample, first create the following directories and files: 
// C:\Users\Public\TestFolder 
// C:\Users\Public\TestFolder\test.txt 
// C:\Users\Public\TestFolder\SubDir\test.txt 
public class SimpleFileCopy
{
    static void Main()
    {
        string fileName = "test.txt";
        string sourcePath = @"C:\Users\Public\TestFolder";
        string targetPath =  @"C:\Users\Public\TestFolder\SubDir";

        // Use Path class to manipulate file and directory paths. 
        string sourceFile = System.IO.Path.Combine(sourcePath, fileName);
        string destFile = System.IO.Path.Combine(targetPath, fileName);

        // To copy a folder's contents to a new location: 
        // Create a new target folder, if necessary. 
        if (!System.IO.Directory.Exists(targetPath))
        {
            System.IO.Directory.CreateDirectory(targetPath);
        }

        // To copy a file to another location and  
        // overwrite the destination file if it already exists.
        System.IO.File.Copy(sourceFile, destFile, true);

        // To copy all the files in one directory to another directory. 
        // Get the files in the source folder. (To recursively iterate through 
        // all subfolders under the current directory, see 
        // "How to: Iterate Through a Directory Tree.")
        // Note: Check for target path was performed previously 
        //       in this code example. 
        if (System.IO.Directory.Exists(sourcePath))
        {
            string[] files = System.IO.Directory.GetFiles(sourcePath);

            // Copy the files and overwrite destination files if they already exist. 
            foreach (string s in files)
            {
                // Use static Path methods to extract only the file name from the path.
                fileName = System.IO.Path.GetFileName(s);
                destFile = System.IO.Path.Combine(targetPath, fileName);
                System.IO.File.Copy(s, destFile, true);
            }
        }
        else
        {
            Console.WriteLine("Source path does not exist!");
        }

        // Keep console window open in debug mode.
        Console.WriteLine("Press any key to exit.");
        Console.ReadKey();
    }
}

Answer 2

foreach (var file in Directory.GetFiles(source))
{
    File.Copy(file, Path.Combine(target, Path.GetFileName(file)), false);
}

Answer 3

foreach (var file in Directory.GetFiles(source))
{
   var targetFile = System.IO.Path.Combine(target, System.IO.Path.GetFileName(file));
   if(!File.Exists(targetFile))
   {
       File.Copy(file, targetFile)
   }
}