Rename files in C# code

using System;
using System.IO;
using System.Threading.Tasks;
using Serilog;

class Program
{
    private const string DIRECTORY_PATH = @"C:\DataFiles\Output\";
    private const string DATA_FILE_EXTENSION = ".data.txt";
    private const string PDF_FILE_EXTENSION = ".PDF";

    static async Task Main()
    {
        // Set up Serilog
        Log.Logger = new LoggerConfiguration()
            .WriteTo.Console()
            .WriteTo.File("log-.txt", rollingInterval: RollingInterval.Day)
            .CreateLogger();

        try
        {
            await RenameDataFilesAsync();
        }
        catch (Exception ex)
        {
            Log.Error(ex, "An unexpected error occurred.");
        }
        finally
        {
            Log.CloseAndFlush();
        }
    }

    static async Task RenameDataFilesAsync()
    {
        if (!Directory.Exists(DIRECTORY_PATH))
        {
            Log.Error($"Directory '{DIRECTORY_PATH}' does not exist.");
            return;
        }

        string[] dataFilePaths = GetDataFiles(DIRECTORY_PATH);

        foreach (string dataFilePath in dataFilePaths)
        {
            await ProcessDataFileAsync(dataFilePath);
        }
    }

    static string[] GetDataFiles(string directoryPath)
    {
        return Directory.GetFiles(directoryPath, "*" + DATA_FILE_EXTENSION);
    }

    static async Task ProcessDataFileAsync(string dataFilePath)
    {
        Log.Information($"Processing file: {dataFilePath}");

        string baseFileName = Path.GetFileNameWithoutExtension(dataFilePath);
        string pdfBaseNameWithoutSuffix = baseFileName.Replace(".data", "");

        string pdfFilePath = Path.Combine(DIRECTORY_PATH, pdfBaseNameWithoutSuffix + PDF_FILE_EXTENSION);

        if (File.Exists(pdfFilePath))
        {
            await RenamePdfFileAsync(pdfFilePath, pdfBaseNameWithoutSuffix);
        }
        else
        {
            Log.Error($"No matching PDF file found for '{dataFilePath}'");
        }
    }

    static async Task RenamePdfFileAsync(string pdfFilePath, string pdfBaseNameWithoutSuffix)
    {
        string newPdfFilePath = Path.Combine(DIRECTORY_PATH, pdfBaseNameWithoutSuffix + "-modified" + PDF_FILE_EXTENSION);

        try
        {
            // File.Move is a synchronous method, but for async, we can use Task.Run to offload it
            await Task.Run(() => File.Move(pdfFilePath, newPdfFilePath));
            Log.Information($"Renamed '{pdfFilePath}' to '{newPdfFilePath}'");
        }
        catch (Exception ex)
        {
            Log.Error(ex, $"Error renaming PDF file: {pdfFilePath}");
        }
    }
}

In this code I have configured Serilog to log to the console and a file. The log file name will have a date suffix and will roll daily. Also File.Move is executed inside a Task.Run to make it asynchronous. Although File.Move itself is synchronous, using Task.Run helps to offload the work to a background thread and fits within an async pattern.

Dear amit,

After Manipulating Code, Reaname activity working Fine.

Thank you

cannot make file name as ""

Dear amit,

The latest one also not working, it showing No matching PDF file

Hi jithu,

Please find the output 

Dear Jithu,

There is no action while run the code and without error

can you please share me the output.

Dear Jithu & Amit

i tried both methods not working 

I think the file search pattern "*.data.txt" is incorrect. It should be "*_data.txt" to match files ending with _data.txt.

using System;
using System.IO;

static void RENAME1()
{
    // Define the directory path where the files are located
    string directoryPath = @"C:\Data\Files\Output";
    
    // Get all data.txt files in the directory
    string[] dataFiles = Directory.GetFiles(directoryPath, "*_data.txt");
    
    foreach (string dataFilePath in dataFiles)
    {
        // Extract the filename without extension
        string baseFileName = Path.GetFileNameWithoutExtension(dataFilePath); // e.g., LP-607-0220-Q-RO_data
        
        // Remove the '_data' suffix to get the new base name for the PDF
        string newPdfBaseName = baseFileName.Replace("_data", ""); // e.g., LP-607-0220-Q-RO
        
        // Find the corresponding PDF file
        string pdfFilePath = Path.Combine(directoryPath, newPdfBaseName + ".pdf"); // Ensure correct casing for extension
        
        if (File.Exists(pdfFilePath))
        {
            // Define the new PDF file path
            string newPdfFilePath = Path.Combine(directoryPath, newPdfBaseName + ".pdf"); // Ensure correct casing for extension
            
            // Rename the PDF file
            File.Move(pdfFilePath, newPdfFilePath);
            Console.WriteLine($"Renamed '{pdfFilePath}' to '{newPdfFilePath}'");
        }
        else
        {
            Console.WriteLine($"No matching PDF file found for '{dataFilePath}'");
        }
    }
}

using System;
using System.IO;

class Program
{
    static void Main()
    {
        RENAME1();
    }

    static void RENAME1()
    {
        // Define the directory path where the files are located
        string directoryPath = @"C:\DataFiles\Output\";

        if (!Directory.Exists(directoryPath))
        {
            Console.WriteLine($"The directory '{directoryPath}' does not exist.");
            return;
        }

        // Get all .data.txt files in the directory
        string[] dataFiles = Directory.GetFiles(directoryPath, "*.data.txt");

        if (dataFiles.Length == 0)
        {
            Console.WriteLine("No .data.txt files found in the directory.");
            return;
        }

        foreach (string dataFilePath in dataFiles)
        {
            Console.WriteLine($"Processing file: {dataFilePath}");

            // Extract the filename without extension
            string baseFileName = Path.GetFileNameWithoutExtension(dataFilePath); // e.g., LP-700-0220-Q-RQ_data

            // Remove the '.data' suffix to get the new base name for the PDF
            string newPdfBaseName = baseFileName.Replace(".data", ""); // e.g., LP-700-0220-Q-RQ

            // Find the corresponding PDF file
            string pdfFilePath = Path.Combine(directoryPath, newPdfBaseName + ".PDF");

            if (File.Exists(pdfFilePath))
            {
                // Define the new PDF file path
                string newPdfFilePath = Path.Combine(directoryPath, newPdfBaseName + "-modified.PDF");

                // Rename the PDF file
                File.Move(pdfFilePath, newPdfFilePath);

                Console.WriteLine($"Renamed '{pdfFilePath}' to '{newPdfFilePath}'");
            }
            else
            {
                Console.WriteLine($"No matching PDF file found for '{dataFilePath}'");
            }
        }
    }
}

Please try this.