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How to remove last characters from a string

So I am writing a C# program which combines several text files into one and saves them as a combined text file. One issue I am having, I have a textfield which selects the intended folder the save the compiled reciept, however when selecting the desired folder, it generates a file name to the text box, the filename follwing the final / must be erased every time for the save function to work properly. I am wondering, how to remove all text after the final letter before the last / in the file directory?
Here is the code:
private void RecieptDisplayed_TextChanged(object sender, EventArgs e)
{
try
{
string[] fileAry = Directory.GetFiles(RecieptSelect.Text);
string input = RecieptSelect.Text;
int index = input.LastIndexOf("/");
if (index >= 0)
input = input.Substring(0, index);
MessageBox.Show("Reciepts being processed : " + index);
using (TextWriter tw = new StreamWriter(savefileas.Text + "RecieptsCombined.txt", true))
{
foreach (string filePath in fileAry)
{
using (TextReader tr = new StreamReader(filePath))
{
tw.WriteLine("Reciept for: " + " " + filePath + tr.ReadToEnd()) ;
tr.Close();
tr.Dispose();
}
MessageBox.Show("File Processed : " + filePath);
}
tw.Close();
tw.Dispose();
}
}

You have a string like
var fullpath = #"C:\temp\myfile.txt";
You can use:
var dir = Path.GetDirectoryName(fullpath);
To get
c:\temp
Note that if the path ends with a slash it doesn't remove it before "going up a directory" so c:\temp\ becomes c:\temp. Try to keep your paths free of trailing slashes
Try to always use the Path class when manipulating string that are paths. It has a whole load of useful methods (this isn't an exhaustive list but the ones I use most) like:
GetFileName
GetFileNameWithoutExtension
GetExtension
ChangeExtension
Combine
This last one builds paths, eg:
Path.Combine("c:", "temp", "myfile.txt");
It knows the different operating systems it runs on and builds paths appropriately - if you're using net core on Linux it uses "/" instead of "\" for example. full docs here

Construct a FileInfo object from the string and then use DirectoryName or Directory.
Also, do not concatenate strings to get a file name, use Path.Combine instead.

You are looking for Directory name from given path, you can use existing function to get the directory name, Path.GetDirectoryName()
using System.IO;
...
//Get the directory name
var directoryName = Path.GetDirectoryName(savefileas.Text);
using (TextWriter tw = new StreamWriter(Path.Combine(directoryName, "RecieptsCombined.txt"), true))
{
foreach (string filePath in fileAry)
{
using (TextReader tr = new StreamReader(filePath))
{
tw.WriteLine("Reciept for: " + " " + filePath + tr.ReadToEnd()) ;
tr.Close();
tr.Dispose();
}
MessageBox.Show("File Processed : " + filePath);
}
tw.Close();
tw.Dispose();
}

Dealing with multiple '.' in a file extension

I have this string that contains a filename
string filename = "C:\\Users\\me\\Desktop\\filename.This.Is.An.Extension"
I tried using the conventional
string modifiedFileName = System.IO.Path.GetFileNameWithoutExtension(filename);
but it only gets me:
modifiedFileName = "C:\\Users\\me\\Desktop\\filename.This.Is.An"
In order for me to get "C:\\Users\\me\\Desktop\\filename" I would have to use System.IO.Path.GetFileNameWithoutExtension several times, and that's just not efficient.
What better way is there to take my file name and have it return the directory + filename and no exceptions?
Many thanks in advance!

If you want to stop at the first period, you will have to handle it yourself.
Path.GetDirectoryName(filepath) + Path.GetFileName(filepath).UpTo(".")
using this string extension:
public static string UpTo(this string s, string stopper) => s.Substring(0, Math.Max(0, s.IndexOf(stopper)));

Take the directory and the base name:
var directoryPath = Path.GetDirectoryName(filename);
var baseName = Path.GetFileName(filename);
Strip the base name’s “extensions”:
var baseNameWithoutExtensions = baseName.Split(new[] {'.'}, 2)[0];
Recombine them:
var modifiedFileName = Path.Combine(directoryPath, baseNameWithoutExtensions);
demo

Without built in function:
public static void Main(string[] args)
{
string s = "C:\\Users\\me\\Desktop\\filename.This.Is.An.Extension";
string newString="";
for(int i=0;i<s.Length;i++)
{
if(s[i]=='.'){
break;
}else{
newString += s[i].ToString();
}
}
Console.WriteLine(newString); //writes "C:\Users\me\Desktop\filename"
}

C# Filter differences from a path

DirectoryPath = C:\Pics
filePath = C:\Pics\Dogs\dog.PNG
newPath should be: Dogs\dog.PNG
How do I get the newPath?
My code snippet is not right
string directoryPath = "C:\\Pics";
string filePath = "C:\\Pics\\Dogs\\dog.PNG";
if (!directoryPath.EndsWith("\\"))
directoryPath = directoryPath + "\\";
string newPath = filePath.Substring(filePath.LastIndexOf(directoryPath) + 1);
Thanks in advance!

Could you append a backslash to the directory path & then in the filepath replace the directory path with an empty string
newPath = filePath.Replace(DirectoryPath + #"\", string.Empty);
If the directoryPath does not match the start of the filePath, then newPath will be unchanged.
I did post this before you edited your code to show the conditional adding of the backslash - so that can be removed in the above code.

The int Index you get from LastIndexOf() will always starts with the rightmost value, in your case 0. You have also to add the String.Lenght for this.
if (filePath.StartsWith(directoryPath))
{
string newPath =
filePath.Substring(filePath.LastIndexOf(directoryPath) + directoryPath.Length + 1);
}

I would first check if filePath contains DirectoryPath,so i'd do something like this:
var newPath=filePath.Contains(DirectoryPath)?filePath.Substring(DirectoryPath.Length + 1)
:filePath;
Or even better,using StartsWith
var newPath=filePath.StartsWith(DirectoryPath)?filePath.Substring(DirectoryPath.Length + 1)
:filePath;

Change extensions of all files in a directory

I don't get an error, but the extension isn't changed.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string filename;
string[] filePaths = Directory.GetFiles(#"c:\Users\Desktop\test\");
Console.WriteLine("Directory consists of " + filePaths.Length + " files.");
foreach(string myfile in filePaths)
filename = Path.ChangeExtension(myfile, ".txt");
Console.ReadLine();
}
}
}

Path.ChangeExtension only returns a string with the new extension, it doesn't rename the file itself.
You need to use System.IO.File.Move(oldName, newName) to rename the actual file, something like this:
foreach (string myfile in filePaths)
{
filename = Path.ChangeExtension(myfile, ".txt");
System.IO.File.Move(myfile, filename);
}

Ìf you want to change the extension of a file, call File.Move().

This only changes extension of path and not of file.
Reason: Since ChangeExtension is called of Path.ChangeExtension. For file, use System.IO. File Class and its methods.

The documentation for method ChangeExtension says that:
Changes the extension of a path string.
It doesn't say that it changes extension for a file.

I think this is roughly equivalent (correct) code:
DirectoryInfo di = new DirectoryInfo(#"c:\Users\Desktop\test\");
foreach (FileInfo fi in di.GetFiles())
{
fi.MoveTo(fi.Name.Substring(0, fi.Name.Length - fi.Extension.Length - 1) + ".txt"); // "test.bat" 8 - 3 - 1 = 4 "test" + ".txt" = "test.txt"
}
Console.WriteLine("Directory consists of " + di.GetFiles().Length + " files.");
Console.ReadLine();

File.Move() rename not working

My app takes "unclean" file names and "cleans" them up. "Unclean" file names contain characters like #, #, ~, +, %, etc. The "cleaning" process replaces those chars with "". However, I found that if there are two files in the same folder that, after a cleaning, will have the same name, my app does not rename either file. (I.e. ##test.txt and ~test.txt will both be named test.txt after the cleaning).
Therefore, I put in a loop that basically checks to see if the file name my app is trying to rename already exists in the folder. However, I tried running this and it would not rename all the files. Am I doing something wrong?
Here's my code:
public void FileCleanup(List<string> paths)
{
string regPattern = (#"[~#&!%+{}]+");
string replacement = "";
Regex regExPattern = new Regex(regPattern);
List<string> existingNames = new List<string>();
StreamWriter errors = new StreamWriter(#"C:\Documents and Settings\joe.schmoe\Desktop\SharePointTesting\Errors.txt");
StreamWriter resultsofRename = new StreamWriter(#"C:\Documents and Settings\joe.schmoe\Desktop\SharePointTesting\Results of File Rename.txt");
var filesCount = new Dictionary<string, int>();
string replaceSpecialCharsWith = "_";
foreach (string files2 in paths)
try
{
string filenameOnly = Path.GetFileName(files2);
string pathOnly = Path.GetDirectoryName(files2);
string sanitizedFileName = regExPattern.Replace(filenameOnly, replacement);
string sanitized = Path.Combine(pathOnly, sanitizedFileName);
if (!System.IO.File.Exists(sanitized))
{
System.IO.File.Move(files2, sanitized);
resultsofRename.Write("Path: " + pathOnly + " / " + "Old File Name: " + filenameOnly + "New File Name: " + sanitized + "\r\n" + "\r\n");
}
else
{
existingNames.Add(sanitized);
foreach (string names in existingNames)
{
string sanitizedPath = regExPattern.Replace(names, replaceSpecialCharsWith);
if (filesCount.ContainsKey(sanitizedPath))
{
filesCount[names]++;
}
else
{
filesCount.Add(sanitizedPath, 1);
}
string newFileName = String.Format("{0},{1}, {2}", Path.GetFileNameWithoutExtension(sanitizedPath),
filesCount[sanitizedPath] != 0
? filesCount[sanitizedPath].ToString()
: "",
Path.GetExtension(sanitizedPath));
string newFilePath = Path.Combine(Path.GetDirectoryName(sanitizedPath), newFileName);
System.IO.File.Move(names, newFileName);
}
}
}
catch (Exception e)
{
//write to streamwriter
}
}
}
Anybody have ANY idea why my code won't rename duplicate files uniquely?

You do foreach (string names in existingNames), but existingNames is empty.
You have your if (System.IO.File.Exists(sanitized)) backwards: it makes up a new name if the file doesn't exist, instead of when it exists.
You make a string newFileName, but still use sanitizedPath instead of newFileName to do the renaming.
The second parameter to filesCount.Add(sanitizedPath, 0) should be 1 or 2. After all, you have then encountered your second file with the same name.
If filesCount[sanitizedPath] equals 0, you don't change the filename at all, so you overwrite the existing file.

In addition to the problem pointed out by Sjoerd, it appears that you are checking to see if the file exists and if it does exist you move it. Your if statement should be
if (!System.IO.File.Exists(sanitized))
{
...
}
else
{
foreach (string names in existingNames)
{
...
}
}
}
Update:
I agree that you should split the code up into smaller methods. It will help you identify which pieces are working and which aren't. That being said, I would get rid of the existingNames list. It is not needed because you have the filesCount Dictionary. Your else clause would then look something like this:
if (filesCount.ContainsKey(sanitized))
{
filesCount[sanitized]++;
}
else
{
filesCount.Add(sanitized, 1);
}
string newFileName = String.Format("{0}{1}.{2}",
Path.GetFileNameWithoutExtension(sanitized),
filesCount[sanitized].ToString(),
Path.GetExtension(sanitized));
string newFilePath = Path.Combine(Path.GetDirectoryName(sanitized), newFileName);
System.IO.File.Move(files2, newFileName);
Please note that I changed your String.Format method call. You had some commas and spaces in there that looked incorrect for building a path, although I could be missing something in your implementation. Also, in the Move I changed the first argument from "names" to "files2".

A good way to make the code less messy would be to split it to methods as logical blocks.
FindUniqueName(string filePath, string fileName);
The method would prefix the fileName with a character, until the fileName is unique withing the filePath.
MoveFile(string filePath, string from, string to);
The method would use the FindUniqueName method if the file already exists.
It would be way easier to test the cleanup that way.
Also you should check if a file actually requires renaming:
if (String.Compare(sanitizedFileName, filenameOnly, true) != 0)
MoveFile(pathOnly, fileNameOnly, sanitizedFileName);
private string FindUniqueName(string fileDirectory, string from, string to)
{
string fileName = to;
// There most likely won't be that many files with the same name to reach max filename length.
while (File.Exists(Path.Combine(fileDirectory, fileName)))
{
fileName = "_" + fileName;
}
return fileName;
}
private void MoveFile(string fileDirectory, string from, string to)
{
to = FindUniqueName(fileDirectory, from, to);
File.Move(Path.Combine(fileDirectory, from), Path.Combine(fileDirectory, to));
}