We Keep Coding

Copy file and if exist create new extension

I have a problem, i am trying to write a program that will copy a file with the same name from A to B and i want to change the exension from bk2 to bk3,4,5,6,7 or just rename the filename so the program can copy the file even if the same name allready exist.
I am very beginner in C# everything is dificult now.
Below the code
enter code here
static void Main(string[] args)
{
//path of file
string pathToOriginalFile = #"D:\C#\LOGS_PROG\SystemLog.bk2";
string extension = ".bk2";
//duplicate file path
string PathForDuplicateFile = #"D:\C#\Backup\Systemlog";
//provide source and destination file paths
File.Copy(pathToOriginalFile, PathForDuplicateFile + extension);
}
}

There is few tips.
You can use System.IO.Path.
path of file
string pathToOriginalFile = #"D:\C#\LOGS_PROG\SystemLog.bk2";
Where the file is located (D:\C#\LOGS_PROG) be careful, there is no \ at the end
string where = Path.GetDirectoryName(pathToOriginalFile);
THe name of the wile without its extension (SystemLog)
string name = Path.GetFileNameWithoutExtension(pathToOriginalFile);
its extension (.bk2)
string extension = Path.GetExtension(pathToOriginalFile);
The name and the extension (SystemLog.bk2)
string nameAndExtension = Path.GetFileName(pathToOriginalFile);
Now, if your purpose is to duplicate the file :
//path of file
string pathToOriginalFile = #"D:\C#\LOGS_PROG\SystemLog.bk2";
for (int i = 1; ; ++i)
{
// For example : D:\C#\LOGS_PROG\SystemLog (9).bk2 if there is the original + 8 copy
string pathToNewFile = Path.Combine(Path.GetDirectoryName(pathToOriginalFile), Path.GetFileNameWithoutExtension(pathToOriginalFile) + " (" + i + ")" + Path.GetExtension(pathToOriginalFile));
if (!File.Exists(pathToNewFile))
{
File.Copy(pathToOriginalFile, pathToNewFile);
break;
}
}
I separated the structure so you can see how it is built but you can use already known variables.

try this:
static void Main(string[] args)
{
//path of file
string pathToOriginalFile = #"D:\C#\LOGS_PROG\SystemLog.bk2";
string extension = ".bk2";
//duplicate file path
string PathForDuplicateFile = #"D:\C#\Backup\Systemlog";
//rename fileName if Exists
FixFileName(ref PathForDuplicateFile, extension);
//provide source and destination file paths
File.Copy(pathToOriginalFile, PathForDuplicateFile + extension);
}
static void FixFileName(ref string PathForDuplicateFile, string extention)
{
int i = 0;
while (true)
{
i++;
if (File.Exists(PathForDuplicateFile + extention))
PathForDuplicateFile += i;
else
break;
}
}

Problem solved.
The program copy the file and if the file exist it renames the extension.
Winndow runs it every day and so i got my autobackup
Thakns for the help!
static void Main(string[] args)
{
//path of file
string pathToOriginalFile = #"C:\Desktop\c#\Logging\Systemlog.bk66";
//duplicate file path
string PathForDuplicateFile = #"C:\\Desktop\c#\Systemlog";
//rename fileName if Exists
FixFileName(ref PathForDuplicateFile, ".bk");
if (File.ReadAllText(pathToOriginalFile).Length > 2000)
{
File.Copy(pathToOriginalFile, PathForDuplicateFile);
}
else
{
}
//provide source and destination file paths
}
static void FixFileName(ref string PathForDuplicateFile, string extention)
{
int i = 0;
while (true)
{
i++;
if (File.Exists(PathForDuplicateFile + extention))
extention += i;
else
break;
}
PathForDuplicateFile += extention;
}
}

How can I change the file name use c#? [duplicate]

How do I rename a file using C#?

Take a look at System.IO.File.Move, "move" the file to a new name.
System.IO.File.Move("oldfilename", "newfilename");

System.IO.File.Move(oldNameFullPath, newNameFullPath);

In the File.Move method, this won't overwrite the file if it is already exists. And it will throw an exception.
So we need to check whether the file exists or not.
/* Delete the file if exists, else no exception thrown. */
File.Delete(newFileName); // Delete the existing file if exists
File.Move(oldFileName,newFileName); // Rename the oldFileName into newFileName
Or surround it with a try catch to avoid an exception.

Just add:
namespace System.IO
{
public static class ExtendedMethod
{
public static void Rename(this FileInfo fileInfo, string newName)
{
fileInfo.MoveTo(fileInfo.Directory.FullName + "\\" + newName);
}
}
}
And then...
FileInfo file = new FileInfo("c:\test.txt");
file.Rename("test2.txt");

You can use File.Move to do it.

First solution
Avoid System.IO.File.Move solutions posted here (marked answer included).
It fails over networks. However, copy/delete pattern works locally and over networks. Follow one of the move solutions, but replace it with Copy instead. Then use File.Delete to delete the original file.
You can create a Rename method to simplify it.
Ease of use
Use the VB assembly in C#.
Add reference to Microsoft.VisualBasic
Then to rename the file:
Microsoft.VisualBasic.FileIO.FileSystem.RenameFile(myfile, newName);
Both are strings. Note that myfile has the full path. newName does not.
For example:
a = "C:\whatever\a.txt";
b = "b.txt";
Microsoft.VisualBasic.FileIO.FileSystem.RenameFile(a, b);
The C:\whatever\ folder will now contain b.txt.

You can copy it as a new file and then delete the old one using the System.IO.File class:
if (File.Exists(oldName))
{
File.Copy(oldName, newName, true);
File.Delete(oldName);
}

public void RenameFile(string filePath, string newName)
{
FileInfo fileInfo = new FileInfo(filePath);
fileInfo.MoveTo(fileInfo.Directory.FullName + "\\" + newName);
}

NOTE: In this example code we open a directory and search for PDF files with open and closed parenthesis in the name of the file. You can check and replace any character in the name you like or just specify a whole new name using replace functions.
There are other ways to work from this code to do more elaborate renames but my main intention was to show how to use File.Move to do a batch rename. This worked against 335 PDF files in 180 directories when I ran it on my laptop. This is spur of the moment code and there are more elaborate ways to do it.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BatchRenamer
{
class Program
{
static void Main(string[] args)
{
var dirnames = Directory.GetDirectories(#"C:\the full directory path of files to rename goes here");
int i = 0;
try
{
foreach (var dir in dirnames)
{
var fnames = Directory.GetFiles(dir, "*.pdf").Select(Path.GetFileName);
DirectoryInfo d = new DirectoryInfo(dir);
FileInfo[] finfo = d.GetFiles("*.pdf");
foreach (var f in fnames)
{
i++;
Console.WriteLine("The number of the file being renamed is: {0}", i);
if (!File.Exists(Path.Combine(dir, f.ToString().Replace("(", "").Replace(")", ""))))
{
File.Move(Path.Combine(dir, f), Path.Combine(dir, f.ToString().Replace("(", "").Replace(")", "")));
}
else
{
Console.WriteLine("The file you are attempting to rename already exists! The file path is {0}.", dir);
foreach (FileInfo fi in finfo)
{
Console.WriteLine("The file modify date is: {0} ", File.GetLastWriteTime(dir));
}
}
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Console.Read();
}
}
}

None of the answers mention writing a unit testable solution. You could use System.IO.Abstractions as it provides a testable wrapper around FileSystem operations, using which you can create a mocked file system objects and write unit tests.
using System.IO.Abstractions;
IFileInfo fileInfo = _fileSystem.FileInfo.FromFileName("filePathAndName");
fileInfo.MoveTo(Path.Combine(fileInfo.DirectoryName, newName));
It was tested, and it is working code to rename a file.

Use:
using System.IO;
string oldFilePath = #"C:\OldFile.txt"; // Full path of old file
string newFilePath = #"C:\NewFile.txt"; // Full path of new file
if (File.Exists(newFilePath))
{
File.Delete(newFilePath);
}
File.Move(oldFilePath, newFilePath);

Use:
public static class FileInfoExtensions
{
/// <summary>
/// Behavior when a new filename exists.
/// </summary>
public enum FileExistBehavior
{
/// <summary>
/// None: throw IOException "The destination file already exists."
/// </summary>
None = 0,
/// <summary>
/// Replace: replace the file in the destination.
/// </summary>
Replace = 1,
/// <summary>
/// Skip: skip this file.
/// </summary>
Skip = 2,
/// <summary>
/// Rename: rename the file (like a window behavior)
/// </summary>
Rename = 3
}
/// <summary>
/// Rename the file.
/// </summary>
/// <param name="fileInfo">the target file.</param>
/// <param name="newFileName">new filename with extension.</param>
/// <param name="fileExistBehavior">behavior when new filename is exist.</param>
public static void Rename(this System.IO.FileInfo fileInfo, string newFileName, FileExistBehavior fileExistBehavior = FileExistBehavior.None)
{
string newFileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(newFileName);
string newFileNameExtension = System.IO.Path.GetExtension(newFileName);
string newFilePath = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileName);
if (System.IO.File.Exists(newFilePath))
{
switch (fileExistBehavior)
{
case FileExistBehavior.None:
throw new System.IO.IOException("The destination file already exists.");
case FileExistBehavior.Replace:
System.IO.File.Delete(newFilePath);
break;
case FileExistBehavior.Rename:
int dupplicate_count = 0;
string newFileNameWithDupplicateIndex;
string newFilePathWithDupplicateIndex;
do
{
dupplicate_count++;
newFileNameWithDupplicateIndex = newFileNameWithoutExtension + " (" + dupplicate_count + ")" + newFileNameExtension;
newFilePathWithDupplicateIndex = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileNameWithDupplicateIndex);
}
while (System.IO.File.Exists(newFilePathWithDupplicateIndex));
newFilePath = newFilePathWithDupplicateIndex;
break;
case FileExistBehavior.Skip:
return;
}
}
System.IO.File.Move(fileInfo.FullName, newFilePath);
}
}
How to use this code
class Program
{
static void Main(string[] args)
{
string targetFile = System.IO.Path.Combine(#"D://test", "New Text Document.txt");
string newFileName = "Foo.txt";
// Full pattern
System.IO.FileInfo fileInfo = new System.IO.FileInfo(targetFile);
fileInfo.Rename(newFileName);
// Or short form
new System.IO.FileInfo(targetFile).Rename(newFileName);
}
}

I couldn't find an approach which suits me, so I propose my version. Of course, it needs input and error handling.
public void Rename(string filePath, string newFileName)
{
var newFilePath = Path.Combine(Path.GetDirectoryName(filePath), newFileName + Path.GetExtension(filePath));
System.IO.File.Move(filePath, newFilePath);
}

In my case, I want the name of the renamed file to be unique, so I add a date-time stamp to the name. This way, the filename of the 'old' log is always unique:
if (File.Exists(clogfile))
{
Int64 fileSizeInBytes = new FileInfo(clogfile).Length;
if (fileSizeInBytes > 5000000)
{
string path = Path.GetFullPath(clogfile);
string filename = Path.GetFileNameWithoutExtension(clogfile);
System.IO.File.Move(clogfile, Path.Combine(path, string.Format("{0}{1}.log", filename, DateTime.Now.ToString("yyyyMMdd_HHmmss"))));
}
}

Move is doing the same = copy and delete old one.
File.Move(#"C:\ScanPDF\Test.pdf", #"C:\BackupPDF\" + string.Format("backup-{0:yyyy-MM-dd_HH:mm:ss}.pdf", DateTime.Now));

// Source file to be renamed
string sourceFile = #"C:\Temp\MaheshChand.jpg";
// Create a FileInfo
System.IO.FileInfo fi = new System.IO.FileInfo(sourceFile);
// Check if file is there
if (fi.Exists)
{
// Move file with a new name. Hence renamed.
fi.MoveTo(#"C:\Temp\Mahesh.jpg");
Console.WriteLine("File Renamed.");
}

public static class ImageRename
{
public static void ApplyChanges(string fileUrl,
string temporaryImageName,
string permanentImageName)
{
var currentFileName = Path.Combine(fileUrl,
temporaryImageName);
if (!File.Exists(currentFileName))
throw new FileNotFoundException();
var extention = Path.GetExtension(temporaryImageName);
var newFileName = Path.Combine(fileUrl,
$"{permanentImageName}
{extention}");
if (File.Exists(newFileName))
File.Delete(newFileName);
File.Move(currentFileName, newFileName);
}
}

I've encountered a case when I had to rename the file inside the event handler, which was triggering for any file change, including rename, and to skip forever renaming of the file I had to rename it, with:
Making its copy
Removing the original
File.Copy(fileFullPath, destFileName); // Both have the format of "D:\..\..\myFile.ext"
Thread.Sleep(100); // Wait for the OS to unfocus the file
File.Delete(fileFullPath);

private static void Rename_File(string FileFullPath, string NewName) // nes name without directory actualy you can simply rename with fileinfo.MoveTo(Fullpathwithnameandextension);
{
FileInfo fileInfo = new FileInfo(FileFullPath);
string DirectoryRoot = Directory.GetParent(FileFullPath).FullName;
string filecreator = FileFullPath.Substring(DirectoryRoot.Length,FileFullPath.Length-DirectoryRoot.Length);
filecreator = DirectoryRoot + NewName;
try
{
fileInfo.MoveTo(filecreator);
}
catch(Exception ex)
{
Console.WriteLine(filecreator);
Console.WriteLine(ex.Message);
Console.ReadKey();
}
enter code here
// string FileDirectory = Directory.GetDirectoryRoot()
}

When C# doesn't have some feature, I use C++ or C:
public partial class Program
{
[DllImport("msvcrt", CallingConvention = CallingConvention.Cdecl, SetLastError = true)]
public static extern int rename(
[MarshalAs(UnmanagedType.LPStr)]
string oldpath,
[MarshalAs(UnmanagedType.LPStr)]
string newpath);
static void FileRename()
{
while (true)
{
Console.Clear();
Console.Write("Enter a folder name: ");
string dir = Console.ReadLine().Trim('\\') + "\\";
if (string.IsNullOrWhiteSpace(dir))
break;
if (!Directory.Exists(dir))
{
Console.WriteLine("{0} does not exist", dir);
continue;
}
string[] files = Directory.GetFiles(dir, "*.mp3");
for (int i = 0; i < files.Length; i++)
{
string oldName = Path.GetFileName(files[i]);
int pos = oldName.IndexOfAny(new char[] { '0', '1', '2' });
if (pos == 0)
continue;
string newName = oldName.Substring(pos);
int res = rename(files[i], dir + newName);
}
}
Console.WriteLine("\n\t\tPress any key to go to main menu\n");
Console.ReadKey(true);
}
}

Copy file, overwrite if newer

In C#.NET, How to copy a file to another location, overwriting the existing file if the source file is newer than the existing file (have a later "Modified date"), and doing noting if the source file is older?

You can use the FileInfo class and it's properties and methods:
FileInfo file = new FileInfo(path);
string destDir = #"C:\SomeDirectory";
FileInfo destFile = new FileInfo(Path.Combine(destDir, file.Name));
if (destFile.Exists)
{
if (file.LastWriteTime > destFile.LastWriteTime)
{
// now you can safely overwrite it
file.CopyTo(destFile.FullName, true);
}
}

You can use the FileInfo class:
FileInfo infoOld = new FileInfo("C:\\old.txt");
FileInfo infoNew = new FileInfo("C:\\new.txt");
if (infoNew.LastWriteTime > infoOld.LastWriteTime)
{
File.Copy(source path,destination path, true) ;
}

Here is my take on the answer: Copies not moves folder contents. If the target does not exist the code is clearer to read. Technically, creating a fileinfo for a non existent file will have a LastWriteTime of DateTime.Min so it would copy but falls a little short on readability. I hope this tested code helps someone.
**EDIT: I have updated my source to be much more flexable. Because it was based on this thread I have posted the update here. When using masks subdirs are not created if the subfolder does not contain matched files. Certainly a more robust error handler is in your future. :)
public void CopyFolderContents(string sourceFolder, string destinationFolder)
{
CopyFolderContents(sourceFolder, destinationFolder, "*.*", false, false);
}
public void CopyFolderContents(string sourceFolder, string destinationFolder, string mask)
{
CopyFolderContents(sourceFolder, destinationFolder, mask, false, false);
}
public void CopyFolderContents(string sourceFolder, string destinationFolder, string mask, Boolean createFolders, Boolean recurseFolders)
{
try
{
if (!sourceFolder.EndsWith(#"\")){ sourceFolder += #"\"; }
if (!destinationFolder.EndsWith(#"\")){ destinationFolder += #"\"; }
var exDir = sourceFolder;
var dir = new DirectoryInfo(exDir);
SearchOption so = (recurseFolders ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly);
foreach (string sourceFile in Directory.GetFiles(dir.ToString(), mask, so))
{
FileInfo srcFile = new FileInfo(sourceFile);
string srcFileName = srcFile.Name;
// Create a destination that matches the source structure
FileInfo destFile = new FileInfo(destinationFolder + srcFile.FullName.Replace(sourceFolder, ""));
if (!Directory.Exists(destFile.DirectoryName ) && createFolders)
{
Directory.CreateDirectory(destFile.DirectoryName);
}
if (srcFile.LastWriteTime > destFile.LastWriteTime || !destFile.Exists)
{
File.Copy(srcFile.FullName, destFile.FullName, true);
}
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex.Message + Environment.NewLine + Environment.NewLine + ex.StackTrace);
}
}

In a batch file, this will work:
XCopy "c:\my directory\source.ext" "c:\my other directory\dest.ext" /d

Automatically rename a file if it already exists in Windows way

My C# code is generating several text files based on input and saving those in a folder. Also, I am assuming that the name of the text file will be same as input.(The input contains only letters)
If two files has same name then it is simply overwriting the previous file.
But I want to keep both files.
I don't want to append current date time or a random number to the 2nd file name. Instead I want to do it the same way Windows does. If the fisrt file name is AAA.txt , then second file name is AAA(2).txt, third file name will be AAA(3).txt.....N th file name will be AAA(N).txt.
string[] allFiles = Directory.GetFiles(folderPath).Select(filename => Path.GetFileNameWithoutExtension(filename)).ToArray();
foreach (var item in allFiles)
{
//newFileName is the txt file which is going to be saved in the provided folder
if (newFileName.Equals(item, StringComparison.InvariantCultureIgnoreCase))
{
// What to do here ?
}
}

This will check for the existence of files with tempFileName and increment the number by one until it finds a name that does not exist in the directory.
int count = 1;
string fileNameOnly = Path.GetFileNameWithoutExtension(fullPath);
string extension = Path.GetExtension(fullPath);
string path = Path.GetDirectoryName(fullPath);
string newFullPath = fullPath;
while(File.Exists(newFullPath))
{
string tempFileName = string.Format("{0}({1})", fileNameOnly, count++);
newFullPath = Path.Combine(path, tempFileName + extension);
}

With this code if file name is "Test (3).txt" then it will become "Test (4).txt".
public static string GetUniqueFilePath(string filePath)
{
if (File.Exists(filePath))
{
string folderPath = Path.GetDirectoryName(filePath);
string fileName = Path.GetFileNameWithoutExtension(filePath);
string fileExtension = Path.GetExtension(filePath);
int number = 1;
Match regex = Regex.Match(fileName, #"^(.+) \((\d+)\)$");
if (regex.Success)
{
fileName = regex.Groups[1].Value;
number = int.Parse(regex.Groups[2].Value);
}
do
{
number++;
string newFileName = $"{fileName} ({number}){fileExtension}";
filePath = Path.Combine(folderPath, newFileName);
}
while (File.Exists(filePath));
}
return filePath;
}

The other examples don't take into account the filename / extension.
Here you go:
public static string GetUniqueFilename(string fullPath)
{
if (!Path.IsPathRooted(fullPath))
fullPath = Path.GetFullPath(fullPath);
if (File.Exists(fullPath))
{
String filename = Path.GetFileName(fullPath);
String path = fullPath.Substring(0, fullPath.Length - filename.Length);
String filenameWOExt = Path.GetFileNameWithoutExtension(fullPath);
String ext = Path.GetExtension(fullPath);
int n = 1;
do
{
fullPath = Path.Combine(path, String.Format("{0} ({1}){2}", filenameWOExt, (n++), ext));
}
while (File.Exists(fullPath));
}
return fullPath;
}

How about just:
int count = 1;
String tempFileName = newFileName;
foreach (var item in allFiles)
{
if (tempFileName.Equals(item, StringComparison.InvariantCultureIgnoreCase))
{
tempFileName = String.Format("{0}({1})", newFileName, count++);
}
}
This will use the original file name if it's not there, if not it'll take a new file name with the index in brackets (although this code isn't taking the extension into account). If the newly generated name "text(001)" is used then it'll increment until it finds a valid unused file name.

public static string AutoRenameFilename(FileInfo file)
{
var filename = file.Name.Replace(file.Extension, string.Empty);
var dir = file.Directory.FullName;
var ext = file.Extension;
if (file.Exists)
{
int count = 0;
string added;
do
{
count++;
added = "(" + count + ")";
} while (File.Exists(dir + "\\" + filename + " " + added + ext));
filename += " " + added;
}
return (dir + filename + ext);
}

int count= 0;
file is the name of file
while (File.Exists(fullpathwithfilename)) //this will check for existence of file
{
// below line names new file from file.xls to file1.xls
fullpathwithfilename= fullpathwithfilename.Replace("file.xls", "file"+count+".xls");
count++;
}

I was looking for a solution that would move a file, and make sure that if the destination file name is not already taken. It would follow the same logic as Windows and append a number, with brackets after the duplicate file.
The top answer, thanks to #cadrell0, helped me arrive to the following solution:
/// <summary>
/// Generates full file path for a file that is to be moved to a destinationFolderDir.
///
/// This method takes into account the possiblity of the file already existing,
/// and will append number surrounded with brackets to the file name.
///
/// E.g. if D:\DestinationDir contains file name file.txt,
/// and your fileToMoveFullPath is D:\Source\file.txt, the generated path will be D:\DestinationDir\file(1).txt
///
/// </summary>
/// <param name="destinationFolderDir">E.g. D:\DestinationDir </param>
/// <param name="fileToMoveFullPath">D:\Source\file.txt</param>
/// <returns></returns>
public string GetFullFilePathWithDuplicatesTakenInMind(string destinationFolderDir, string fileToMoveFullPath)
{
string destinationPathWithDuplicatesTakenInMind;
string fileNameWithExtension = Path.GetFileName(fileToMoveFullPath);
string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(fileToMoveFullPath);
string fileNameExtension = Path.GetExtension(fileToMoveFullPath);
destinationPathWithDuplicatesTakenInMind = Path.Combine(destinationFolderDir, fileNameWithExtension);
int count = 0;
while (File.Exists(destinationPathWithDuplicatesTakenInMind))
{
destinationPathWithDuplicatesTakenInMind = Path.Combine(destinationFolderDir, $"{fileNameWithoutExtension}({count}){fileNameExtension}");
count = count + 1; // sorry, not a fan of the ++ operator.
}
return destinationPathWithDuplicatesTakenInMind;
}

With regard to Giuseppe's comment on the way windows renames files I worked on a version that finds any existing index i.e. (2) in the file name and renames the file as per windows accordingly. The sourceFileName is assumed to be valid and the user is assumed to have write permission on the destination folder by this point:
using System.IO;
using System.Text.RegularExpressions;
private void RenameDiskFileToMSUnique(string sourceFileName)
{
string destFileName = "";
long n = 1;
// ensure the full path is qualified
if (!Path.IsPathRooted(sourceFileName)) { sourceFileName = Path.GetFullPath(sourceFileName); }
string filepath = Path.GetDirectoryName(sourceFileName);
string fileNameWOExt = Path.GetFileNameWithoutExtension(sourceFileName);
string fileNameSuffix = "";
string fileNameExt = Path.GetExtension(sourceFileName);
// if the name includes the text "(0-9)" then we have a filename, instance number and suffix
Regex r = new Regex(#"\(\d+\)");
Match match = r.Match(fileNameWOExt);
if (match.Success) // the pattern (0-9) was found
{
// text after the match
if (fileNameWOExt.Length > match.Index + match.Length) // remove the format and create the suffix
{
fileNameSuffix = fileNameWOExt.Substring(match.Index + match.Length, fileNameWOExt.Length - (match.Index + match.Length));
fileNameWOExt = fileNameWOExt.Substring(0, match.Index);
}
else // remove the format at the end
{
fileNameWOExt = fileNameWOExt.Substring(0, fileNameWOExt.Length - match.Length);
}
// increment the numeric in the name
n = Convert.ToInt64(match.Value.Substring(1, match.Length - 2)) + 1;
}
// format variation: indexed text retains the original layout, new suffixed text inserts a space!
do
{
if (match.Success) // the text was already indexed
{
if (fileNameSuffix.Length > 0)
{
destFileName = Path.Combine(filepath, String.Format("{0}({1}){2}{3}", fileNameWOExt, (n++), fileNameSuffix, fileNameExt));
}
else
{
destFileName = Path.Combine(filepath, String.Format("{0}({1}){2}", fileNameWOExt, (n++), fileNameExt));
}
}
else // we are adding a new index
{
destFileName = Path.Combine(filepath, String.Format("{0} ({1}){2}", fileNameWOExt, (n++), fileNameExt));
}
}
while (File.Exists(destFileName));
File.Copy(sourceFileName, destFileName);
}

You can declare a Dictionary<string,int> to keep the number of times each root file name was saved. After that, on your Save method, just increase the counter and append it to the base file name:
var key = fileName.ToLower();
string newFileName;
if(!_dictionary.ContainsKey(key))
{
newFileName = fileName;
_dictionary.Add(key,0);
}
else
{
_dictionary[key]++;
newFileName = String.Format("{0}({1})", fileName, _dictionary[key])
}
This way, you'll have a counter for each distinct file name: AAA(1), AAA(2); BBB(1)...

It's working fine now. thanks guys for the answers..
string[] allFiles = Directory.GetFiles(folderPath).Select(filename => Path.GetFileNameWithoutExtension(filename)).ToArray();
string tempFileName = fileName;
int count = 1;
while (allFiles.Contains(tempFileName ))
{
tempFileName = String.Format("{0} ({1})", fileName, count++);
}
output = Path.Combine(folderPath, tempFileName );
string fullPath=output + ".xml";

Rename a file in C#

How do I rename a file using C#?

Take a look at System.IO.File.Move, "move" the file to a new name.
System.IO.File.Move("oldfilename", "newfilename");

System.IO.File.Move(oldNameFullPath, newNameFullPath);

In the File.Move method, this won't overwrite the file if it is already exists. And it will throw an exception.
So we need to check whether the file exists or not.
/* Delete the file if exists, else no exception thrown. */
File.Delete(newFileName); // Delete the existing file if exists
File.Move(oldFileName,newFileName); // Rename the oldFileName into newFileName
Or surround it with a try catch to avoid an exception.

Just add:
namespace System.IO
{
public static class ExtendedMethod
{
public static void Rename(this FileInfo fileInfo, string newName)
{
fileInfo.MoveTo(fileInfo.Directory.FullName + "\\" + newName);
}
}
}
And then...
FileInfo file = new FileInfo("c:\test.txt");
file.Rename("test2.txt");

You can use File.Move to do it.

First solution
Avoid System.IO.File.Move solutions posted here (marked answer included).
It fails over networks. However, copy/delete pattern works locally and over networks. Follow one of the move solutions, but replace it with Copy instead. Then use File.Delete to delete the original file.
You can create a Rename method to simplify it.
Ease of use
Use the VB assembly in C#.
Add reference to Microsoft.VisualBasic
Then to rename the file:
Microsoft.VisualBasic.FileIO.FileSystem.RenameFile(myfile, newName);
Both are strings. Note that myfile has the full path. newName does not.
For example:
a = "C:\whatever\a.txt";
b = "b.txt";
Microsoft.VisualBasic.FileIO.FileSystem.RenameFile(a, b);
The C:\whatever\ folder will now contain b.txt.

You can copy it as a new file and then delete the old one using the System.IO.File class:
if (File.Exists(oldName))
{
File.Copy(oldName, newName, true);
File.Delete(oldName);
}

public void RenameFile(string filePath, string newName)
{
FileInfo fileInfo = new FileInfo(filePath);
fileInfo.MoveTo(fileInfo.Directory.FullName + "\\" + newName);
}

NOTE: In this example code we open a directory and search for PDF files with open and closed parenthesis in the name of the file. You can check and replace any character in the name you like or just specify a whole new name using replace functions.
There are other ways to work from this code to do more elaborate renames but my main intention was to show how to use File.Move to do a batch rename. This worked against 335 PDF files in 180 directories when I ran it on my laptop. This is spur of the moment code and there are more elaborate ways to do it.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BatchRenamer
{
class Program
{
static void Main(string[] args)
{
var dirnames = Directory.GetDirectories(#"C:\the full directory path of files to rename goes here");
int i = 0;
try
{
foreach (var dir in dirnames)
{
var fnames = Directory.GetFiles(dir, "*.pdf").Select(Path.GetFileName);
DirectoryInfo d = new DirectoryInfo(dir);
FileInfo[] finfo = d.GetFiles("*.pdf");
foreach (var f in fnames)
{
i++;
Console.WriteLine("The number of the file being renamed is: {0}", i);
if (!File.Exists(Path.Combine(dir, f.ToString().Replace("(", "").Replace(")", ""))))
{
File.Move(Path.Combine(dir, f), Path.Combine(dir, f.ToString().Replace("(", "").Replace(")", "")));
}
else
{
Console.WriteLine("The file you are attempting to rename already exists! The file path is {0}.", dir);
foreach (FileInfo fi in finfo)
{
Console.WriteLine("The file modify date is: {0} ", File.GetLastWriteTime(dir));
}
}
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Console.Read();
}
}
}

None of the answers mention writing a unit testable solution. You could use System.IO.Abstractions as it provides a testable wrapper around FileSystem operations, using which you can create a mocked file system objects and write unit tests.
using System.IO.Abstractions;
IFileInfo fileInfo = _fileSystem.FileInfo.FromFileName("filePathAndName");
fileInfo.MoveTo(Path.Combine(fileInfo.DirectoryName, newName));
It was tested, and it is working code to rename a file.

Use:
using System.IO;
string oldFilePath = #"C:\OldFile.txt"; // Full path of old file
string newFilePath = #"C:\NewFile.txt"; // Full path of new file
if (File.Exists(newFilePath))
{
File.Delete(newFilePath);
}
File.Move(oldFilePath, newFilePath);

Use:
public static class FileInfoExtensions
{
/// <summary>
/// Behavior when a new filename exists.
/// </summary>
public enum FileExistBehavior
{
/// <summary>
/// None: throw IOException "The destination file already exists."
/// </summary>
None = 0,
/// <summary>
/// Replace: replace the file in the destination.
/// </summary>
Replace = 1,
/// <summary>
/// Skip: skip this file.
/// </summary>
Skip = 2,
/// <summary>
/// Rename: rename the file (like a window behavior)
/// </summary>
Rename = 3
}
/// <summary>
/// Rename the file.
/// </summary>
/// <param name="fileInfo">the target file.</param>
/// <param name="newFileName">new filename with extension.</param>
/// <param name="fileExistBehavior">behavior when new filename is exist.</param>
public static void Rename(this System.IO.FileInfo fileInfo, string newFileName, FileExistBehavior fileExistBehavior = FileExistBehavior.None)
{
string newFileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(newFileName);
string newFileNameExtension = System.IO.Path.GetExtension(newFileName);
string newFilePath = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileName);
if (System.IO.File.Exists(newFilePath))
{
switch (fileExistBehavior)
{
case FileExistBehavior.None:
throw new System.IO.IOException("The destination file already exists.");
case FileExistBehavior.Replace:
System.IO.File.Delete(newFilePath);
break;
case FileExistBehavior.Rename:
int dupplicate_count = 0;
string newFileNameWithDupplicateIndex;
string newFilePathWithDupplicateIndex;
do
{
dupplicate_count++;
newFileNameWithDupplicateIndex = newFileNameWithoutExtension + " (" + dupplicate_count + ")" + newFileNameExtension;
newFilePathWithDupplicateIndex = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileNameWithDupplicateIndex);
}
while (System.IO.File.Exists(newFilePathWithDupplicateIndex));
newFilePath = newFilePathWithDupplicateIndex;
break;
case FileExistBehavior.Skip:
return;
}
}
System.IO.File.Move(fileInfo.FullName, newFilePath);
}
}
How to use this code
class Program
{
static void Main(string[] args)
{
string targetFile = System.IO.Path.Combine(#"D://test", "New Text Document.txt");
string newFileName = "Foo.txt";
// Full pattern
System.IO.FileInfo fileInfo = new System.IO.FileInfo(targetFile);
fileInfo.Rename(newFileName);
// Or short form
new System.IO.FileInfo(targetFile).Rename(newFileName);
}
}

I couldn't find an approach which suits me, so I propose my version. Of course, it needs input and error handling.
public void Rename(string filePath, string newFileName)
{
var newFilePath = Path.Combine(Path.GetDirectoryName(filePath), newFileName + Path.GetExtension(filePath));
System.IO.File.Move(filePath, newFilePath);
}

In my case, I want the name of the renamed file to be unique, so I add a date-time stamp to the name. This way, the filename of the 'old' log is always unique:
if (File.Exists(clogfile))
{
Int64 fileSizeInBytes = new FileInfo(clogfile).Length;
if (fileSizeInBytes > 5000000)
{
string path = Path.GetFullPath(clogfile);
string filename = Path.GetFileNameWithoutExtension(clogfile);
System.IO.File.Move(clogfile, Path.Combine(path, string.Format("{0}{1}.log", filename, DateTime.Now.ToString("yyyyMMdd_HHmmss"))));
}
}

Move is doing the same = copy and delete old one.
File.Move(#"C:\ScanPDF\Test.pdf", #"C:\BackupPDF\" + string.Format("backup-{0:yyyy-MM-dd_HH:mm:ss}.pdf", DateTime.Now));

// Source file to be renamed
string sourceFile = #"C:\Temp\MaheshChand.jpg";
// Create a FileInfo
System.IO.FileInfo fi = new System.IO.FileInfo(sourceFile);
// Check if file is there
if (fi.Exists)
{
// Move file with a new name. Hence renamed.
fi.MoveTo(#"C:\Temp\Mahesh.jpg");
Console.WriteLine("File Renamed.");
}

public static class ImageRename
{
public static void ApplyChanges(string fileUrl,
string temporaryImageName,
string permanentImageName)
{
var currentFileName = Path.Combine(fileUrl,
temporaryImageName);
if (!File.Exists(currentFileName))
throw new FileNotFoundException();
var extention = Path.GetExtension(temporaryImageName);
var newFileName = Path.Combine(fileUrl,
$"{permanentImageName}
{extention}");
if (File.Exists(newFileName))
File.Delete(newFileName);
File.Move(currentFileName, newFileName);
}
}

I've encountered a case when I had to rename the file inside the event handler, which was triggering for any file change, including rename, and to skip forever renaming of the file I had to rename it, with:
Making its copy
Removing the original
File.Copy(fileFullPath, destFileName); // Both have the format of "D:\..\..\myFile.ext"
Thread.Sleep(100); // Wait for the OS to unfocus the file
File.Delete(fileFullPath);

private static void Rename_File(string FileFullPath, string NewName) // nes name without directory actualy you can simply rename with fileinfo.MoveTo(Fullpathwithnameandextension);
{
FileInfo fileInfo = new FileInfo(FileFullPath);
string DirectoryRoot = Directory.GetParent(FileFullPath).FullName;
string filecreator = FileFullPath.Substring(DirectoryRoot.Length,FileFullPath.Length-DirectoryRoot.Length);
filecreator = DirectoryRoot + NewName;
try
{
fileInfo.MoveTo(filecreator);
}
catch(Exception ex)
{
Console.WriteLine(filecreator);
Console.WriteLine(ex.Message);
Console.ReadKey();
}
enter code here
// string FileDirectory = Directory.GetDirectoryRoot()
}

When C# doesn't have some feature, I use C++ or C:
public partial class Program
{
[DllImport("msvcrt", CallingConvention = CallingConvention.Cdecl, SetLastError = true)]
public static extern int rename(
[MarshalAs(UnmanagedType.LPStr)]
string oldpath,
[MarshalAs(UnmanagedType.LPStr)]
string newpath);
static void FileRename()
{
while (true)
{
Console.Clear();
Console.Write("Enter a folder name: ");
string dir = Console.ReadLine().Trim('\\') + "\\";
if (string.IsNullOrWhiteSpace(dir))
break;
if (!Directory.Exists(dir))
{
Console.WriteLine("{0} does not exist", dir);
continue;
}
string[] files = Directory.GetFiles(dir, "*.mp3");
for (int i = 0; i < files.Length; i++)
{
string oldName = Path.GetFileName(files[i]);
int pos = oldName.IndexOfAny(new char[] { '0', '1', '2' });
if (pos == 0)
continue;
string newName = oldName.Substring(pos);
int res = rename(files[i], dir + newName);
}
}
Console.WriteLine("\n\t\tPress any key to go to main menu\n");
Console.ReadKey(true);
}
}