Acquire FLV URL from YouTube - c#

There are a lot of questions of a very similar nature, but as of yet I'm unable to find anything which answers this question directly. A lot of responses include "look at the source code of this" and contain a link, unfortunately I'm struggling to analyse the source code in those links, so I'm hoping someone can give me something step by step.
Here is what I have so far:
Request link from end user (e.g www.youtube.com/watch?v=2FlgVN03fNM)
Send HTTP Request to URL, acquire source.
Regex the source to find some information (presumably a series of elements which can be concatenated to form a link to the FLV.
Download the FLV.
Convert the FLV into MP3 or whichever format you'd like.
I have already achieved steps 1, 2, 5, and they all do exactly what I want, but it seems there is a lack of clarity around how to do step 3. Could someone please break this down a little further? Example:
Regex for "XXXXXXXXX"
This line contains all information you need
Split the string by "YYY" to acquire a list of elements
Find all the elements which match "ZZZZZ"
Use those elements to create the FLV link
This would be very useful to me, and if possible I'd love steps or a very simple application in C# or PHP which extracts the link.

Here is a more concise implementation based on Pafy:
using System;
using System.Linq;
using HttpUtility = System.Web.HttpUtility;
using NameValueCollection = System.Collections.Specialized.NameValueCollection;
using WebClient = System.Net.WebClient;
class Program {
public static void Main(string[] args) {
string videoID = "2FlgVN03fNM";
string[] itagByPriority = {"5", "6", "34", "35"};
string videoUrl = "https://www.youtube.com/get_video_info?asv=3&el=detailpage&hl=en_US&video_id=" + videoID;
string encodedVideo = null;
using (var client = new WebClient()) {
encodedVideo = client.DownloadString(videoUrl);
}
NameValueCollection video = HttpUtility.ParseQueryString(encodedVideo);
string encodedStreamsCommaDelimited = video["url_encoded_fmt_stream_map"];
string[] encodedStreams = encodedStreamsCommaDelimited.Split(new char[]{','});
var streams = encodedStreams.Select(s => HttpUtility.ParseQueryString(s));
var streamsByPriority = streams.OrderBy(s => Array.IndexOf(itagByPriority, s["itag"]));
NameValueCollection preferredStream = streamsByPriority.LastOrDefault();
if (preferredStream != null) {
Console.WriteLine("{0}&signature={1}", preferredStream["url"], preferredStream["sig"]);
}
}
}

If you want to skip to a simple code sample for this, you can see the full source on GitHub: https://github.com/XtrmJosh/YouTubeDownloader
I was pretty much right with my assumptions, and although it's taken me 10 hours or so, I've finally achieved what I set out to do. Here is a rough breakdown:
Escape string to ensure we don't break anything
Run some fancy RegEx and what not to capture the exact areas of string we're looking for
Find signatures and what not in each of the URLs we find (we'll find a lot, and we need to narrow them down a fair bit before they can be used)
Add the signature we find for each URL to it, otherwise we get trash files
Scan for some itags, so we know what file type is associated with each link - I only want FLV files.
Append the video name to the URL, and download.
So here is the code I'm using to get all the video URLs in a HTML document (YouTube only - so far)
public static List<string> ExtractUrls(string html)
{
string title = GetTitle(html);
List<string> urls = new List<string>();
string DataBlockStart = "\"url_encoded_fmt_stream_map\":\\s+\"(.+?)&"; // Marks start of Javascript Data Block
html = Uri.UnescapeDataString(Regex.Match(html, DataBlockStart, RegexOptions.Singleline).Groups[1].ToString());
string firstPatren = html.Substring(0, html.IndexOf('=') + 1);
var matchs = Regex.Split(html, firstPatren);
for (int i = 0; i < matchs.Length; i++)
matchs[i] = firstPatren + matchs[i];
foreach (var match in matchs)
{
if (!match.Contains("url=")) continue;
string url = GetTxtBtwn(match, "url=", "\\u0026", 0, false);
if (url == "") url = GetTxtBtwn(match, "url=", ",url", 0, false);
if (url == "") url = GetTxtBtwn(match, "url=", "\",", 0, false);
string sig = GetTxtBtwn(match, "sig=", "\\u0026", 0, false);
if (sig == "") sig = GetTxtBtwn(match, "sig=", ",sig", 0, false);
if (sig == "") sig = GetTxtBtwn(match, "sig=", "\",", 0, false);
while ((url.EndsWith(",")) || (url.EndsWith(".")) || (url.EndsWith("\"")))
url = url.Remove(url.Length - 1, 1);
while ((sig.EndsWith(",")) || (sig.EndsWith(".")) || (sig.EndsWith("\"")))
sig = sig.Remove(sig.Length - 1, 1);
if (string.IsNullOrEmpty(url)) continue;
if (!string.IsNullOrEmpty(sig))
url += "&signature=" + sig;
urls.Add(url);
}
for (int i = 0; i < urls.Count; i++)
{
urls[i] += "&title=";
urls[i] += title;
}
return urls;
}
public static string GetTitle(string RssDoc)
{
string str14 = GetTxtBtwn(RssDoc, "'VIDEO_TITLE': '", "'", 0, false);
if (str14 == "") str14 = GetTxtBtwn(RssDoc, "\"title\" content=\"", "\"", 0, false);
if (str14 == "") str14 = GetTxtBtwn(RssDoc, "&title=", "&", 0, false);
str14 = str14.Replace(#"\", "").Replace("'", "'").Replace("\"", """).Replace("<", "<").Replace(">", ">").Replace("+", " ");
return str14;
}
public static string GetTxtBtwn(string input, string start, string end, int startIndex, bool UseLastIndexOf)
{
int index1 = UseLastIndexOf ? input.LastIndexOf(start, startIndex) :
input.IndexOf(start, startIndex);
if (index1 == -1) return "";
index1 += start.Length;
int index2 = input.IndexOf(end, index1);
if (index2 == -1) return input.Substring(index1);
return input.Substring(index1, index2 - index1);
}
This code will (with the current YouTube format) provide a link to an FLV file which you can download and do what you like with (within the TOS of YouTube). I then used this to find the highest quality link from those that this code provided:
public static string GetFLV(List<string> urls)
{
// Acquire a list of links which match the criteria for being FLV files
List<string> flvurls = new List<string>();
foreach (string url in urls)
{
string itag = Regex.Match(url, #"itag=([1-9]?[0-9]?[0-9])", RegexOptions.Singleline).Groups[1].ToString();
int itagint;
int.TryParse(itag, out itagint);
if (itagint == 5 || itagint == 6 || itagint == 34 || itagint == 35)
{
flvurls.Add(url);
}
}
// If we didn't find any FLVs, we return a fatal error and cause a bug later on
if (flvurls.Count == 0)
{
MessageBox.Show("Fatal error | iTag could not be found for FLV filetype. Please contact software vendor for assistance.");
return "";
}
// If we did find some FLVs, we need to find the highest quality FLV
else
{
#region findBestFLV
foreach (string url in flvurls)
{
string itag = Regex.Match(url, #"itag=([1-9]?[0-9]?[0-9])", RegexOptions.Singleline).Groups[1].ToString();
int itagint;
int.TryParse(itag, out itagint);
if (itagint == 35)
{
return url;
}
}
foreach (string url in flvurls)
{
string itag = Regex.Match(url, #"itag=([1-9]?[0-9]?[0-9])", RegexOptions.Singleline).Groups[1].ToString();
int itagint;
int.TryParse(itag, out itagint);
if (itagint == 34)
{
return url;
}
}
foreach (string url in flvurls)
{
string itag = Regex.Match(url, #"itag=([1-9]?[0-9]?[0-9])", RegexOptions.Singleline).Groups[1].ToString();
int itagint;
int.TryParse(itag, out itagint);
if (itagint == 6)
{
return url;
}
}
foreach (string url in flvurls)
{
string itag = Regex.Match(url, #"itag=([1-9]?[0-9]?[0-9])", RegexOptions.Singleline).Groups[1].ToString();
int itagint;
int.TryParse(itag, out itagint);
if (itagint == 5)
{
return url;
}
}
#endregion
}
MessageBox.Show("Fatal error | Something has gone horrible wrong whilst finding the best FLV to use. Run, brave warrior, for the end is near.");
return "";
}
Note it is very scrappy at the minute, the rest of the code is mostly snippets I've borrowed and edited slightly, but this bit I've written from my head in some rushed attempt to get something together for SOF.
Hope this helps someone else :)

Related

Search raw text from url, using keyword from textbox

Me and my buddy Xylophone have been at this for hours and cant figure this out, any help would be appreciated. I'm basically trying to read all the text from that URL and search for a keyword.
if (comboBoxEdit1.Text == "Hello")
{
label2.Text = "Current Status: Searching...";
this.dataGridView3.ScrollBars = ScrollBars.None;
this.dataGridView3.MouseWheel += new MouseEventHandler(mousewheel);
dataGridView3.Rows.Clear();
string line;
int row = 0;
List<String> LinesFound = new List<string>();
StreamReader file = new StreamReader("https://pastebin.com/raw/fWxKdRjN");
while ((line = file.ReadLine()) != null)
{
if (line.Contains(textEdit1.Text))
{
string[] Columns = line.Split(':');
dataGridView3.Rows.Add(line);
for (int i = 0; i < Columns.Length; i++)
{
dataGridView3[i, row].Value = Columns[i];
}
row++;
label2.Text = "Current Status: " + dataGridView3.Rows.Count + " Matche(s) Found";
}
else if (dataGridView3.RowCount == 0)
{
label2.Text = "Current Status: No Matche(s) Found";
}
}
}
You are doing it all wrong, if you want to read and pars the html content of the web page, you need to fetch the page using httpClient, or better take look at this library https://html-agility-pack.net/
We can use regular expression to check if 'raw' exist in the URL.
Regex.Matches() function will return an array with all occurrence of the match.
We can then use count property to find the no of occurence.
Regular expression to match raw in a url:(raw)
Below is the working code snippet:
public static void Main()
{
string pattern = #"(raw)";
Regex rgx = new Regex(pattern);
string url = "https://pastebin.com/raw/fWxKdRjN";
if (rgx.Matches(url).Count>0){
Console.WriteLine(Current Status: " + rgx.Matches(url).Count + " Matche(s) Found");
}
else {
Console.WriteLine("Current Status: No Matche(s) Found");
}
}

Automatically rename a file if it already exists with SaveFileDialog [duplicate]

I would like to create a method which takes either a filename as a string or a FileInfo and adds an incremented number to the filename if the file exists. But can't quite wrap my head around how to do this in a good way.
For example, if I have this FileInfo
var file = new FileInfo(#"C:\file.ext");
I would like the method to give me a new FileInfo with C:\file 1.ext if C:\file.ext
existed, and C:\file 2.ext if C:\file 1.ext existed and so on. Something like this:
public FileInfo MakeUnique(FileInfo fileInfo)
{
if(fileInfo == null)
throw new ArgumentNullException("fileInfo");
if(!fileInfo.Exists)
return fileInfo;
// Somehow construct new filename from the one we have, test it,
// then do it again if necessary.
}
public FileInfo MakeUnique(string path)
{
string dir = Path.GetDirectoryName(path);
string fileName = Path.GetFileNameWithoutExtension(path);
string fileExt = Path.GetExtension(path);
for (int i = 1; ;++i) {
if (!File.Exists(path))
return new FileInfo(path);
path = Path.Combine(dir, fileName + " " + i + fileExt);
}
}
Obviously, this is vulnerable to race conditions as noted in other answers.
Lots of good advice here. I ended up using a method written by Marc in an answer to a different question. Reformatted it a tiny bit and added another method to make it a bit easier to use "from the outside". Here is the result:
private static string numberPattern = " ({0})";
public static string NextAvailableFilename(string path)
{
// Short-cut if already available
if (!File.Exists(path))
return path;
// If path has extension then insert the number pattern just before the extension and return next filename
if (Path.HasExtension(path))
return GetNextFilename(path.Insert(path.LastIndexOf(Path.GetExtension(path)), numberPattern));
// Otherwise just append the pattern to the path and return next filename
return GetNextFilename(path + numberPattern);
}
private static string GetNextFilename(string pattern)
{
string tmp = string.Format(pattern, 1);
if (tmp == pattern)
throw new ArgumentException("The pattern must include an index place-holder", "pattern");
if (!File.Exists(tmp))
return tmp; // short-circuit if no matches
int min = 1, max = 2; // min is inclusive, max is exclusive/untested
while (File.Exists(string.Format(pattern, max)))
{
min = max;
max *= 2;
}
while (max != min + 1)
{
int pivot = (max + min) / 2;
if (File.Exists(string.Format(pattern, pivot)))
min = pivot;
else
max = pivot;
}
return string.Format(pattern, max);
}
Only partially tested it so far, but will update if I find any bugs with it. (Marcs code works nicely!) If you find any problems with it, please comment or edit or something :)
Not pretty, but I've had this for a while :
private string getNextFileName(string fileName)
{
string extension = Path.GetExtension(fileName);
int i = 0;
while (File.Exists(fileName))
{
if (i == 0)
fileName = fileName.Replace(extension, "(" + ++i + ")" + extension);
else
fileName = fileName.Replace("(" + i + ")" + extension, "(" + ++i + ")" + extension);
}
return fileName;
}
Assuming the files already exist:
File.txt
File(1).txt
File(2).txt
the call getNextFileName("File.txt") will return "File(3).txt".
Not the most efficient because it doesn't use binary search, but should be ok for small file count. And it doesn't take race condition into account...
If checking if the file exists is too hard you can always just add a date and time to the file name to make it unique:
FileName.YYYYMMDD.HHMMSS
Maybe even add milliseconds if necessary.
If the format doesn't bother you then you can call:
try{
string tempFile=System.IO.Path.GetTempFileName();
string file=System.IO.Path.GetFileName(tempFile);
//use file
System.IO.File.Delete(tempFile);
}catch(IOException ioe){
//handle
}catch(FileIOPermission fp){
//handle
}
PS:- Please read more about this at msdn before using.
/// <summary>
/// Create a unique filename for the given filename
/// </summary>
/// <param name="filename">A full filename, e.g., C:\temp\myfile.tmp</param>
/// <returns>A filename like C:\temp\myfile633822247336197902.tmp</returns>
public string GetUniqueFilename(string filename)
{
string basename = Path.Combine(Path.GetDirectoryName(filename),
Path.GetFileNameWithoutExtension(filename));
string uniquefilename = string.Format("{0}{1}{2}",
basename,
DateTime.Now.Ticks,
Path.GetExtension(filename));
// Thread.Sleep(1); // To really prevent collisions, but usually not needed
return uniquefilename;
}
As DateTime.Ticks has a resolution of 100 nanoseconds, collisions are extremely unlikely. However, a Thread.Sleep(1) will ensure that, but I doubt that it's needed
Insert a new GUID into the file name.
I must throw my 2-cents in. This is how I did it and it works for my use.
private static string IterateFileName(string fileName)
{
if (!File.Exists(fileName)) return fileName;
FileInfo fi = new FileInfo(fileName);
string ext = fi.Extension;
string name = fi.FullName.Substring(0, fi.FullName.Length - ext.Length);
int i = 2;
while (File.Exists($"{name}_{i}{ext}"))
{
i++;
}
return $"{name}_{i}{ext}";
}
The idea is to get a list of the existing files, parse out the numbers, then make the next highest one.
Note: This is vulnerable to race conditions, so if you have more than one thread creating these files, be careful.
Note 2: This is untested.
public static FileInfo GetNextUniqueFile(string path)
{
//if the given file doesn't exist, we're done
if(!File.Exists(path))
return new FileInfo(path);
//split the path into parts
string dirName = Path.GetDirectoryName(path);
string fileName = Path.GetFileNameWithoutExtension(path);
string fileExt = Path.GetExtension(path);
//get the directory
DirectoryInfo dir = new DirectoryInfo(dir);
//get the list of existing files for this name and extension
var existingFiles = dir.GetFiles(Path.ChangeExtension(fileName + " *", fileExt);
//get the number strings from the existing files
var NumberStrings = from file in existingFiles
select Path.GetFileNameWithoutExtension(file.Name)
.Remove(0, fileName.Length /*we remove the space too*/);
//find the highest existing number
int highestNumber = 0;
foreach(var numberString in NumberStrings)
{
int tempNum;
if(Int32.TryParse(numberString, out tempnum) && tempNum > highestNumber)
highestNumber = tempNum;
}
//make the new FileInfo object
string newFileName = fileName + " " + (highestNumber + 1).ToString();
newFileName = Path.ChangeExtension(fileName, fileExt);
return new FileInfo(Path.Combine(dirName, newFileName));
}
Instead of poking the disk a number of times to find out if it has a particular variant of the desired file name, you could ask for the list of files that already exist and find the first gap according to your algorithm.
public static class FileInfoExtensions
{
public static FileInfo MakeUnique(this FileInfo fileInfo)
{
if (fileInfo == null)
{
throw new ArgumentNullException("fileInfo");
}
string newfileName = new FileUtilities().GetNextFileName(fileInfo.FullName);
return new FileInfo(newfileName);
}
}
public class FileUtilities
{
public string GetNextFileName(string fullFileName)
{
if (fullFileName == null)
{
throw new ArgumentNullException("fullFileName");
}
if (!File.Exists(fullFileName))
{
return fullFileName;
}
string baseFileName = Path.GetFileNameWithoutExtension(fullFileName);
string ext = Path.GetExtension(fullFileName);
string filePath = Path.GetDirectoryName(fullFileName);
var numbersUsed = Directory.GetFiles(filePath, baseFileName + "*" + ext)
.Select(x => Path.GetFileNameWithoutExtension(x).Substring(baseFileName.Length))
.Select(x =>
{
int result;
return Int32.TryParse(x, out result) ? result : 0;
})
.Distinct()
.OrderBy(x => x)
.ToList();
var firstGap = numbersUsed
.Select((x, i) => new { Index = i, Item = x })
.FirstOrDefault(x => x.Index != x.Item);
int numberToUse = firstGap != null ? firstGap.Item : numbersUsed.Count;
return Path.Combine(filePath, baseFileName) + numberToUse + ext;
}
}
Here's one that decouples the numbered naming question from the check of the filesystem:
/// <summary>
/// Finds the next unused unique (numbered) filename.
/// </summary>
/// <param name="fileName">Name of the file.</param>
/// <param name="inUse">Function that will determine if the name is already in use</param>
/// <returns>The original filename if it wasn't already used, or the filename with " (n)"
/// added to the name if the original filename is already in use.</returns>
private static string NextUniqueFilename(string fileName, Func<string, bool> inUse)
{
if (!inUse(fileName))
{
// this filename has not been seen before, return it unmodified
return fileName;
}
// this filename is already in use, add " (n)" to the end
var name = Path.GetFileNameWithoutExtension(fileName);
var extension = Path.GetExtension(fileName);
if (name == null)
{
throw new Exception("File name without extension returned null.");
}
const int max = 9999;
for (var i = 1; i < max; i++)
{
var nextUniqueFilename = string.Format("{0} ({1}){2}", name, i, extension);
if (!inUse(nextUniqueFilename))
{
return nextUniqueFilename;
}
}
throw new Exception(string.Format("Too many files by this name. Limit: {0}", max));
}
And here's how you might call it if you are using the filesystem
var safeName = NextUniqueFilename(filename, f => File.Exists(Path.Combine(folder, f)));
private async Task<CloudBlockBlob> CreateBlockBlob(CloudBlobContainer container, string blobNameToCreate)
{
var blockBlob = container.GetBlockBlobReference(blobNameToCreate);
var i = 1;
while (await blockBlob.ExistsAsync())
{
var newBlobNameToCreate = CreateRandomFileName(blobNameToCreate,i.ToString());
blockBlob = container.GetBlockBlobReference(newBlobNameToCreate);
i++;
}
return blockBlob;
}
private string CreateRandomFileName(string fileNameWithExtension, string prefix=null)
{
int fileExtPos = fileNameWithExtension.LastIndexOf(".", StringComparison.Ordinal);
if (fileExtPos >= 0)
{
var ext = fileNameWithExtension.Substring(fileExtPos, fileNameWithExtension.Length - fileExtPos);
var fileName = fileNameWithExtension.Substring(0, fileExtPos);
return String.Format("{0}_{1}{2}", fileName, String.IsNullOrWhiteSpace(prefix) ? new Random().Next(int.MinValue, int.MaxValue).ToString():prefix,ext);
}
//This means there is no Extension for the file and its fine attaching random number at the end.
return String.Format("{0}_{1}", fileNameWithExtension, new Random().Next(int.MinValue, int.MaxValue));
}
I use this code to create a consecutive _1,_2,_3 etc.. file name everytime a file exists in the blob storage.
Hope this self iterating function may help. It works fine for me.
public string getUniqueFileName(int i, string filepath, string filename)
{
string path = Path.Combine(filepath, filename);
if (System.IO.File.Exists(path))
{
string name = Path.GetFileNameWithoutExtension(filename);
string ext = Path.GetExtension(filename);
i++;
filename = getUniqueFileName(i, filepath, name + "_" + i + ext);
}
return filename;
}
This is an answer to question in this Link, but they marked it as a duplicate, so I post my answer here.
I created this proof of concept class (may contain bugs).
More explanation in code comments.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
namespace ConsoleApp
{
class Program
{
static void Main( string[] args )
{
var testFilePaths = new List<string>
{
#"c:\test\file.txt",
#"c:\test\file(1).txt",
#"c:\test\file(2).txt",
#"c:\TEST2\file(3).txt",
#"c:\test\file(5).txt",
#"c:\test\file(5)abc.txt",
#"c:\test\file(5).avi"
};
// inspect in debbuger for correct values
var withSuffix = new DecomposedFilePath( "c:\\files\\file(13).txt");
var withoutSuffix = new DecomposedFilePath( "c:\\files\\file(abc).txt");
var withExtraNumber = new DecomposedFilePath( "c:\\files\\file(34)xyz(35).txt"); // "(34)" in the middle should be ignored
DecomposedFilePath changedSuffix = withExtraNumber.ReplaceSuffix( 1999 ); // "file(34)xyz(35).txt" -> "file(34)xyz(1999).txt"
DecomposedFilePath removedSuffix = changedSuffix.ReplaceSuffix( null ); // "file(34)xyz(1999).txt" -> "file(34)xyz.txt"
var testPath = new DecomposedFilePath( "c:\\test\\file.txt");
DecomposedFilePath nextPath1 = testPath.GetFirstFreeFilePath( testFilePaths );
// update our list
testFilePaths.Add( nextPath1.FullFilePath );
DecomposedFilePath nextPath2 = testPath.GetFirstFreeFilePath( testFilePaths );
testFilePaths.Add( nextPath2.FullFilePath );
DecomposedFilePath nextPath3 = testPath.GetFirstFreeFilePath( testFilePaths );
}
}
public sealed class DecomposedFilePath
{
public DecomposedFilePath( string filePath )
{
FullFilePath = Path.GetFullPath( filePath );
}
// "c:\myfiles\file(4).txt"
public string FullFilePath { get; }
// "file" or "file(1)"
public string FileNameWithoutExt => Path.GetFileNameWithoutExtension( FullFilePath );
// "file(13)" -> "file"
public string FileNameWithoutExtAndSuffix => FileNameWithoutExt.Substring( 0, FileNameWithoutExt.Length - Suffix.Length ); // removes suffix
// ".txt"
public string Extenstion => Path.GetExtension( FullFilePath );
// "c:\myfiles"
public string DirectoryPath => Path.GetDirectoryName( FullFilePath );
// "file(23)" -> "23", file -> stirng.Empty
public string Suffix
{
get
{
// we want to extract suffix from file name, e.g. "(34)" from "file(34)"
// I am not good at regex, but I hope it will work correctly
var regex = new Regex( #"\([0-9]+\)$" );
Match match = regex.Match( FileNameWithoutExt );
if (!match.Success) return string.Empty; // suffix not found
return match.Value; // return "(number)"
}
}
// tranlates suffix "(33)" to 33. If suffix is does not exist (string.empty), returns null (int?)
public int? SuffixAsInt
{
get
{
if (Suffix == string.Empty) return null;
string numberOnly = Suffix.Substring( 1, Suffix.Length - 2 ); // remove '(' from beginning and ')' from end
return int.Parse( numberOnly );
}
}
// e.g. input is suffix: 56 then it changes file name from "file(34)" to "file(56)"
public DecomposedFilePath ReplaceSuffix( int? suffix ) // null - removes suffix
{
string strSuffix = suffix is null ? string.Empty : $"({suffix})"; // add ( and )
string path = Path.Combine( DirectoryPath, FileNameWithoutExtAndSuffix + strSuffix + Extenstion ); // build full path
return new DecomposedFilePath( path );
}
public DecomposedFilePath GetFirstFreeFilePath( IEnumerable<string> filesInDir )
{
var decomposed = filesInDir
// convert all paths to our class
.Select( x => new DecomposedFilePath( x ) )
// pick files only with the same extensionm as our base file, ignore case
.Where( x => string.Equals( Extenstion, x.Extenstion, StringComparison.OrdinalIgnoreCase) )
// pick files only with the same name (ignoring suffix)
.Where( x => string.Equals( FileNameWithoutExtAndSuffix, x.FileNameWithoutExtAndSuffix, StringComparison.OrdinalIgnoreCase) )
// with the same directory
.Where( x => string.Equals( DirectoryPath, x.DirectoryPath, StringComparison.OrdinalIgnoreCase) )
.ToList(); // create copy for easier debugging
if (decomposed.Count == 0) return this; // no name collision
int? firstFreeSuffix = Enumerable.Range( 1, int.MaxValue) // start numbering duplicates from 1
.Select( x => (int?) x) // change to int? because SuffixAsInt is of that type
.Except( decomposed.Select( x => x.SuffixAsInt) ) // remove existing suffixes
.First(); // get first free suffix
return ReplaceSuffix( firstFreeSuffix );
}
public override string ToString() => FullFilePath;
}
}
This is just a string operation; find the location in the filename string where you want to insert the number, and re-construct a new string with the number inserted. To make it re-usable, you might want to look for a number in that location, and parse it out into an integer, so you can increment it.
Please note that this in general this way of generating a unique filename is insecure; there are obvious race condition hazards.
There might be ready-made solutions for this in the platform, I'm not up to speed with C# so I can't help there.
Take a look at the methods in the Path class, specifically Path.GetFileNameWithoutExtension(), and Path.GetExtension().
You may even find Path.GetRandomFileName() useful!
Edit:
In the past, I've used the technique of attempting to write the file (with my desired name), and then using the above functions to create a new name if an appropriate IOException is thrown, repeating until successful.
This method will add a index to existing file if needed:
If the file exist, find the position of the last underscore. If the content after the underscore is a number, increase this number. otherwise add first index. repeat until unused file name found.
static public string AddIndexToFileNameIfNeeded(string sFileNameWithPath)
{
string sFileNameWithIndex = sFileNameWithPath;
while (File.Exists(sFileNameWithIndex)) // run in while scoop so if after adding an index the the file name the new file name exist, run again until find a unused file name
{ // File exist, need to add index
string sFilePath = Path.GetDirectoryName(sFileNameWithIndex);
string sFileName = Path.GetFileNameWithoutExtension(sFileNameWithIndex);
string sFileExtension = Path.GetExtension(sFileNameWithIndex);
if (sFileName.Contains('_'))
{ // Need to increase the existing index by one or add first index
int iIndexOfUnderscore = sFileName.LastIndexOf('_');
string sContentAfterUnderscore = sFileName.Substring(iIndexOfUnderscore + 1);
// check if content after last underscore is a number, if so increase index by one, if not add the number _01
int iCurrentIndex;
bool bIsContentAfterLastUnderscoreIsNumber = int.TryParse(sContentAfterUnderscore, out iCurrentIndex);
if (bIsContentAfterLastUnderscoreIsNumber)
{
iCurrentIndex++;
string sContentBeforUnderscore = sFileName.Substring(0, iIndexOfUnderscore);
sFileName = sContentBeforUnderscore + "_" + iCurrentIndex.ToString("000");
sFileNameWithIndex = sFilePath + "\\" + sFileName + sFileExtension;
}
else
{
sFileNameWithIndex = sFilePath + "\\" + sFileName + "_001" + sFileExtension;
}
}
else
{ // No underscore in file name. Simple add first index
sFileNameWithIndex = sFilePath + "\\" + sFileName + "_001" + sFileExtension;
}
}
return sFileNameWithIndex;
}
I did it like this:
for (int i = 0; i <= 500; i++) //I suppose the number of files will not pass 500
{ //Checks if C:\log\log+TheNumberOfTheFile+.txt exists...
if (System.IO.File.Exists(#"C:\log\log"+conta_logs+".txt"))
{
conta_logs++;//If exists, then increment the counter
}
else
{ //If not, then the file is created
var file = System.IO.File.Create(#"C:\log\log" + conta_logs + ".txt");
break; //When the file is created we LEAVE the *for* loop
}
}
I think this version is not so hard like the others, and It's a straightforward answer for what the user wanted.
If you need just a unique file name, so, how about this?
Path.GetRandomFileName()
I ran into this problem and, since none of the other answers seemed to have solved it in the way I wanted to, I did it on my own.
static string CheckIfFileExists(string filePath)
{
if (File.Exists(filePath))
{
string parentDir = Directory.GetParent(filePath).FullName;
string fileName = new DirectoryInfo(filePath).Name;
string extension = Path.GetExtension(fileName);
fileName = Path.GetFileNameWithoutExtension(fileName);
if (CheckIfFileNameHasIndex(fileName))
{
string strIndex = fileName[(fileName.LastIndexOf('(')+1)..fileName.LastIndexOf(')')]; //range
int index = int.Parse(strIndex);
index++;
fileName = fileName.Substring(0, fileName.LastIndexOf('(')) + "(" + index + ')';
filePath = Path.Combine(parentDir, fileName + extension);
return CheckIfFileExists(filePath);
}
else
{
fileName = fileName + " (1)";
filePath = Path.Combine(parentDir, fileName + extension);
return CheckIfFileExists(filePath);
}
}
return filePath;
}
//checks if filename has an index (e.g. "file(2).jpg")
static bool CheckIfFileNameHasIndex(string fileName)
{
bool isSuccessful = false;
if (fileName.LastIndexOf('(')!=-1 && fileName.LastIndexOf(')')!=-1)
{
string index = fileName[(fileName.LastIndexOf('(')+1)..fileName.LastIndexOf(')')]; //range
int result;
isSuccessful = int.TryParse(index, out result);
}
return isSuccessful;
}
The method CheckIfFileExists is recursive, so in theory it should be able to handle a potentially unlimited number of duplicates (e.g. "file (3484939).txt"). Of course, in reality, what happens is that the maximum imposed filename length of your operating system and stuff like eventually become a bottleneck.
I have written a method that returns "next" file name with number.
Supports numbering from 1 to 99.
Examples:
C:\Recovery.txt → C:\Recovery1.txt
C:\Recovery1.txt → C:\Recovery2.txt
How to call:
while (File.Exists( path ))
path = NextFileNum( path );
internal static string NextFileNum( string path )
{
string filename = Path.GetFileNameWithoutExtension( path );
string ext = Path.GetExtension( path );
string dir = Path.GetDirectoryName( path );
for (int i = 99; i > 0; i--)
{
if (filename.EndsWith( i.ToString() ))
{
string suffix = ( i + 1 ).ToString();
filename = filename.Substring( 0, filename.Length - suffix.Length ) + suffix;
return Path.Combine( dir, filename + ext );
}
}
filename = filename + "1";
return Path.Combine( dir, filename + ext );
}
public static string MakeUniqueFilePath(string filePath)
{
if (!File.Exists(filePath)) return filePath;
var directory = Path.GetDirectoryName(filePath);
var fileName = Path.GetFileNameWithoutExtension(filePath);
var fileExt = Path.GetExtension(filePath);
var i = 1;
do
{
filePath = Path.Combine(directory, fileName + "(" + i + ")" + fileExt);
i++;
} while (File.Exists(filePath));
return filePath;
}
Returns files like so:
test.txt
test(1).txt
test(2).txt
etc.
Notes:
Can handle filenames without extensions
Can Handle directories included in the file path.
Does not handle file creation race conditions when saving.

C# Socket File Transfer POST method

What i'm trying to do is writing a simple HTTP daemon with c#. I managed to support the GET method, but the POST method seems to be harder. I have to parse multipart formdata and also saving files on the server that have been sent via FILE Upload.
What I'm actually doing:
Check if SocketBuffer Substring contains POST method
Looking for the boundary tag
& extracting it
Read the header from boundarytag to boundary tag
while saving the substring between these two tags in an array.
Parsing each arrayfield - checking if it contains any data that has
to be saved on disk.
If it contains data: reading
"content-disposition", "filename", "content-type" and the data
itself.
public string parse_boundary(string boundary)
{
if (contains_data(boundary))
{
get_content_disposition(boundary);
get_filename(boundary);
get_contenttype(boundary);
get_binarydata(boundary);
}
else
{
Console.WriteLine("No DATA!");
}
return "";
}
public string get_content_disposition(string substring)
{
int first, last;
first = substring.IndexOf("Content-Disposition") + "Content-Disposition:".Length;
last = substring.IndexOf("Content-Type:");
string content_disposition = substring.Substring(first, (last - first));
content_disposition = content_disposition.Replace("\t", "").Replace("\r", "").Replace("\n","");
#if DEBUG_MODE
Console.WriteLine("DEBUG content_disposition: " + content_disposition);
#endif
return content_disposition;
}
public string get_filename(string substring)
{
int first, last;
first = substring.IndexOf("filename=\"") + "filename=\"".Length;
last = substring.IndexOf("\"", first);
string filename = substring.Substring(first, (last - first));
#if DEBUG_MODE
Console.WriteLine("DEBUG Filename: " + filename);
#endif
return filename;
}
public string get_contenttype(string substring)
{
int first, last;
first = substring.IndexOf("Content-Type:", substring.IndexOf("Content-Disposition") + "Content_Type:".Length);
last = substring.IndexOf("\n", first);
string content_type = substring.Substring(first, (last - first));
content_type = content_type.Trim();
#if DEBUG_MODE
Console.WriteLine("DEBUG Content-Type: " + content_type);
#endif
return content_type;
}
public void get_binarydata(string substring)
{
int first, second, last;
first = substring.IndexOf("Content-Type:", substring.IndexOf("Content-Disposition") + "Content_Type:".Length);
second = substring.IndexOf("\n", first);
last = substring.Length;
string tobinary = substring.Substring(second, (last - second));
//tobinary = tobinary.TrimStart();
#if DEBUG_MODE
Console.WriteLine("DEBUG get_binarydata: " + tobinary);
#endif
byte[] encoded_binary = System.Text.Encoding.UTF8.GetBytes(tobinary);
ByteArrayToFile(get_filename(substring), encoded_binary);
}
public bool ByteArrayToFile(string _Filename, byte[] _ByteArray)
{
try
{
System.IO.FileStream _FileStream = new System.IO.FileStream(_Filename, System.IO.FileMode.Create, System.IO.FileAccess.Write);
_FileStream.Write(_ByteArray, 0, _ByteArray.Length);
_FileStream.Close();
return true;
}
catch (Exception _Exception)
{
Console.WriteLine("Exeception caught in process: {0}", _Exception.ToString());
}
return false;
}
public bool contains_data(string boundary)
{
int idx = boundary.IndexOf("Content-Type:");
if (idx == -1)
{
return false;
}
else
{
return true;
}
}
I know there has to be more try/catch blocks but this is just experimentally and not for production use. I also have to mention that my BufferSize is [1024 * MAX_UPLOAD_SIZE] (which is currently set to 2MB).
Now to my problem: When I try to upload an image via file upload my imagefile is ALWAYS 2MB of size (BufferSize). When I try to upload any other data than txt files the files are not fully decoded and unusable. Any ideas how to fix this?

Using Key like "[]Server" into sortedDictionary, but why?

I am trying to understand and probably reuse part of DevExpress Demo code to save simple settings into ini file. I know I can use .NET System.Configuration doing what I want. Just for a smallish project, simple save it as a text file seem more flexible and light-weighted, at least that is what it seems.
Anyway, while I am playing with it, I am trying to understand why the code I am reading trying to add key as "[]Server" and "[]DBFormat" as key name. They do that for a reason I can not understand yet, I could probably use some help here.
Here is the Code I think relevant:
public class IniFile {
SortedDictionary<string, string> data = new SortedDictionary<string, string>();
...
public void Load(string path) {
using(StreamReader sr = new StreamReader(path)) {
string folder = "[]";
while(!sr.EndOfStream) {
string s = sr.ReadLine().Trim();
if(s.Length == 0 || s[0] == ';') continue;
if(s[0] == '[') {
folder = s;
continue;
}
string key, value;
int delim = s.IndexOf('=');
if(delim < 0) {
key = folder + s.Replace("[", string.Empty).Replace("]", string.Empty);
value = string.Empty;
} else {
key = folder + s.Remove(delim).TrimEnd().Replace("[", string.Empty).Replace("]", string.Empty);
value = s.Substring(delim + 1).TrimStart();
}
if(!data.ContainsKey(key)) data.Add(key, value);
else data[key] = value;
}
}
}
...
public void Save(string path) {
using(StreamWriter sw = new StreamWriter(path)) {
string folder = "[]";
foreach(string key in data.Keys) {
int delim = key.IndexOf(']');
string keyFolder = key.Remove(delim + 1);
string keyName = key.Substring(delim + 1);
if(keyFolder != folder) {
folder = keyFolder;
sw.WriteLine(folder);
}
sw.WriteLine(keyName + " = " + data[key]);
}
}
}
void AddRawValue(string key, string value) {
key = key.Trim();
value = value.Trim();
int folderBegin = key.IndexOf('[');
int folderEnd = key.IndexOf(']');
if(folderBegin != 0 || folderEnd < 0) throw new ArgumentException("key");
data.Add(key, value);
}
And here is part of the ini file itself:
DBFormat = "Mdb"
Login = "admin"
Password = ""
Server = "(localhost)"
Obvious, they go though the trouble to add [] into keyname for some reason, but end up not using it in the demo data. I am think they are using string inside [] to group settings?
I only skimmed it, but I'd imagine the intent might have been "[section]setting" so "[]setting" would represent a setting not in a section. Look how easy it is to get values, just a single string will do! (There seems to be confusion between a "section" and a "folder" -- which might be an above-par variable name for that code...)
Then again, I could be way off as I only invested about 10 seconds of time on that tripe >:)
Happy coding.

How would you make a unique filename by adding a number?

I would like to create a method which takes either a filename as a string or a FileInfo and adds an incremented number to the filename if the file exists. But can't quite wrap my head around how to do this in a good way.
For example, if I have this FileInfo
var file = new FileInfo(#"C:\file.ext");
I would like the method to give me a new FileInfo with C:\file 1.ext if C:\file.ext
existed, and C:\file 2.ext if C:\file 1.ext existed and so on. Something like this:
public FileInfo MakeUnique(FileInfo fileInfo)
{
if(fileInfo == null)
throw new ArgumentNullException("fileInfo");
if(!fileInfo.Exists)
return fileInfo;
// Somehow construct new filename from the one we have, test it,
// then do it again if necessary.
}
public FileInfo MakeUnique(string path)
{
string dir = Path.GetDirectoryName(path);
string fileName = Path.GetFileNameWithoutExtension(path);
string fileExt = Path.GetExtension(path);
for (int i = 1; ;++i) {
if (!File.Exists(path))
return new FileInfo(path);
path = Path.Combine(dir, fileName + " " + i + fileExt);
}
}
Obviously, this is vulnerable to race conditions as noted in other answers.
Lots of good advice here. I ended up using a method written by Marc in an answer to a different question. Reformatted it a tiny bit and added another method to make it a bit easier to use "from the outside". Here is the result:
private static string numberPattern = " ({0})";
public static string NextAvailableFilename(string path)
{
// Short-cut if already available
if (!File.Exists(path))
return path;
// If path has extension then insert the number pattern just before the extension and return next filename
if (Path.HasExtension(path))
return GetNextFilename(path.Insert(path.LastIndexOf(Path.GetExtension(path)), numberPattern));
// Otherwise just append the pattern to the path and return next filename
return GetNextFilename(path + numberPattern);
}
private static string GetNextFilename(string pattern)
{
string tmp = string.Format(pattern, 1);
if (tmp == pattern)
throw new ArgumentException("The pattern must include an index place-holder", "pattern");
if (!File.Exists(tmp))
return tmp; // short-circuit if no matches
int min = 1, max = 2; // min is inclusive, max is exclusive/untested
while (File.Exists(string.Format(pattern, max)))
{
min = max;
max *= 2;
}
while (max != min + 1)
{
int pivot = (max + min) / 2;
if (File.Exists(string.Format(pattern, pivot)))
min = pivot;
else
max = pivot;
}
return string.Format(pattern, max);
}
Only partially tested it so far, but will update if I find any bugs with it. (Marcs code works nicely!) If you find any problems with it, please comment or edit or something :)
Not pretty, but I've had this for a while :
private string getNextFileName(string fileName)
{
string extension = Path.GetExtension(fileName);
int i = 0;
while (File.Exists(fileName))
{
if (i == 0)
fileName = fileName.Replace(extension, "(" + ++i + ")" + extension);
else
fileName = fileName.Replace("(" + i + ")" + extension, "(" + ++i + ")" + extension);
}
return fileName;
}
Assuming the files already exist:
File.txt
File(1).txt
File(2).txt
the call getNextFileName("File.txt") will return "File(3).txt".
Not the most efficient because it doesn't use binary search, but should be ok for small file count. And it doesn't take race condition into account...
If checking if the file exists is too hard you can always just add a date and time to the file name to make it unique:
FileName.YYYYMMDD.HHMMSS
Maybe even add milliseconds if necessary.
If the format doesn't bother you then you can call:
try{
string tempFile=System.IO.Path.GetTempFileName();
string file=System.IO.Path.GetFileName(tempFile);
//use file
System.IO.File.Delete(tempFile);
}catch(IOException ioe){
//handle
}catch(FileIOPermission fp){
//handle
}
PS:- Please read more about this at msdn before using.
/// <summary>
/// Create a unique filename for the given filename
/// </summary>
/// <param name="filename">A full filename, e.g., C:\temp\myfile.tmp</param>
/// <returns>A filename like C:\temp\myfile633822247336197902.tmp</returns>
public string GetUniqueFilename(string filename)
{
string basename = Path.Combine(Path.GetDirectoryName(filename),
Path.GetFileNameWithoutExtension(filename));
string uniquefilename = string.Format("{0}{1}{2}",
basename,
DateTime.Now.Ticks,
Path.GetExtension(filename));
// Thread.Sleep(1); // To really prevent collisions, but usually not needed
return uniquefilename;
}
As DateTime.Ticks has a resolution of 100 nanoseconds, collisions are extremely unlikely. However, a Thread.Sleep(1) will ensure that, but I doubt that it's needed
Insert a new GUID into the file name.
I must throw my 2-cents in. This is how I did it and it works for my use.
private static string IterateFileName(string fileName)
{
if (!File.Exists(fileName)) return fileName;
FileInfo fi = new FileInfo(fileName);
string ext = fi.Extension;
string name = fi.FullName.Substring(0, fi.FullName.Length - ext.Length);
int i = 2;
while (File.Exists($"{name}_{i}{ext}"))
{
i++;
}
return $"{name}_{i}{ext}";
}
The idea is to get a list of the existing files, parse out the numbers, then make the next highest one.
Note: This is vulnerable to race conditions, so if you have more than one thread creating these files, be careful.
Note 2: This is untested.
public static FileInfo GetNextUniqueFile(string path)
{
//if the given file doesn't exist, we're done
if(!File.Exists(path))
return new FileInfo(path);
//split the path into parts
string dirName = Path.GetDirectoryName(path);
string fileName = Path.GetFileNameWithoutExtension(path);
string fileExt = Path.GetExtension(path);
//get the directory
DirectoryInfo dir = new DirectoryInfo(dir);
//get the list of existing files for this name and extension
var existingFiles = dir.GetFiles(Path.ChangeExtension(fileName + " *", fileExt);
//get the number strings from the existing files
var NumberStrings = from file in existingFiles
select Path.GetFileNameWithoutExtension(file.Name)
.Remove(0, fileName.Length /*we remove the space too*/);
//find the highest existing number
int highestNumber = 0;
foreach(var numberString in NumberStrings)
{
int tempNum;
if(Int32.TryParse(numberString, out tempnum) && tempNum > highestNumber)
highestNumber = tempNum;
}
//make the new FileInfo object
string newFileName = fileName + " " + (highestNumber + 1).ToString();
newFileName = Path.ChangeExtension(fileName, fileExt);
return new FileInfo(Path.Combine(dirName, newFileName));
}
Instead of poking the disk a number of times to find out if it has a particular variant of the desired file name, you could ask for the list of files that already exist and find the first gap according to your algorithm.
public static class FileInfoExtensions
{
public static FileInfo MakeUnique(this FileInfo fileInfo)
{
if (fileInfo == null)
{
throw new ArgumentNullException("fileInfo");
}
string newfileName = new FileUtilities().GetNextFileName(fileInfo.FullName);
return new FileInfo(newfileName);
}
}
public class FileUtilities
{
public string GetNextFileName(string fullFileName)
{
if (fullFileName == null)
{
throw new ArgumentNullException("fullFileName");
}
if (!File.Exists(fullFileName))
{
return fullFileName;
}
string baseFileName = Path.GetFileNameWithoutExtension(fullFileName);
string ext = Path.GetExtension(fullFileName);
string filePath = Path.GetDirectoryName(fullFileName);
var numbersUsed = Directory.GetFiles(filePath, baseFileName + "*" + ext)
.Select(x => Path.GetFileNameWithoutExtension(x).Substring(baseFileName.Length))
.Select(x =>
{
int result;
return Int32.TryParse(x, out result) ? result : 0;
})
.Distinct()
.OrderBy(x => x)
.ToList();
var firstGap = numbersUsed
.Select((x, i) => new { Index = i, Item = x })
.FirstOrDefault(x => x.Index != x.Item);
int numberToUse = firstGap != null ? firstGap.Item : numbersUsed.Count;
return Path.Combine(filePath, baseFileName) + numberToUse + ext;
}
}
Here's one that decouples the numbered naming question from the check of the filesystem:
/// <summary>
/// Finds the next unused unique (numbered) filename.
/// </summary>
/// <param name="fileName">Name of the file.</param>
/// <param name="inUse">Function that will determine if the name is already in use</param>
/// <returns>The original filename if it wasn't already used, or the filename with " (n)"
/// added to the name if the original filename is already in use.</returns>
private static string NextUniqueFilename(string fileName, Func<string, bool> inUse)
{
if (!inUse(fileName))
{
// this filename has not been seen before, return it unmodified
return fileName;
}
// this filename is already in use, add " (n)" to the end
var name = Path.GetFileNameWithoutExtension(fileName);
var extension = Path.GetExtension(fileName);
if (name == null)
{
throw new Exception("File name without extension returned null.");
}
const int max = 9999;
for (var i = 1; i < max; i++)
{
var nextUniqueFilename = string.Format("{0} ({1}){2}", name, i, extension);
if (!inUse(nextUniqueFilename))
{
return nextUniqueFilename;
}
}
throw new Exception(string.Format("Too many files by this name. Limit: {0}", max));
}
And here's how you might call it if you are using the filesystem
var safeName = NextUniqueFilename(filename, f => File.Exists(Path.Combine(folder, f)));
private async Task<CloudBlockBlob> CreateBlockBlob(CloudBlobContainer container, string blobNameToCreate)
{
var blockBlob = container.GetBlockBlobReference(blobNameToCreate);
var i = 1;
while (await blockBlob.ExistsAsync())
{
var newBlobNameToCreate = CreateRandomFileName(blobNameToCreate,i.ToString());
blockBlob = container.GetBlockBlobReference(newBlobNameToCreate);
i++;
}
return blockBlob;
}
private string CreateRandomFileName(string fileNameWithExtension, string prefix=null)
{
int fileExtPos = fileNameWithExtension.LastIndexOf(".", StringComparison.Ordinal);
if (fileExtPos >= 0)
{
var ext = fileNameWithExtension.Substring(fileExtPos, fileNameWithExtension.Length - fileExtPos);
var fileName = fileNameWithExtension.Substring(0, fileExtPos);
return String.Format("{0}_{1}{2}", fileName, String.IsNullOrWhiteSpace(prefix) ? new Random().Next(int.MinValue, int.MaxValue).ToString():prefix,ext);
}
//This means there is no Extension for the file and its fine attaching random number at the end.
return String.Format("{0}_{1}", fileNameWithExtension, new Random().Next(int.MinValue, int.MaxValue));
}
I use this code to create a consecutive _1,_2,_3 etc.. file name everytime a file exists in the blob storage.
Hope this self iterating function may help. It works fine for me.
public string getUniqueFileName(int i, string filepath, string filename)
{
string path = Path.Combine(filepath, filename);
if (System.IO.File.Exists(path))
{
string name = Path.GetFileNameWithoutExtension(filename);
string ext = Path.GetExtension(filename);
i++;
filename = getUniqueFileName(i, filepath, name + "_" + i + ext);
}
return filename;
}
This is an answer to question in this Link, but they marked it as a duplicate, so I post my answer here.
I created this proof of concept class (may contain bugs).
More explanation in code comments.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
namespace ConsoleApp
{
class Program
{
static void Main( string[] args )
{
var testFilePaths = new List<string>
{
#"c:\test\file.txt",
#"c:\test\file(1).txt",
#"c:\test\file(2).txt",
#"c:\TEST2\file(3).txt",
#"c:\test\file(5).txt",
#"c:\test\file(5)abc.txt",
#"c:\test\file(5).avi"
};
// inspect in debbuger for correct values
var withSuffix = new DecomposedFilePath( "c:\\files\\file(13).txt");
var withoutSuffix = new DecomposedFilePath( "c:\\files\\file(abc).txt");
var withExtraNumber = new DecomposedFilePath( "c:\\files\\file(34)xyz(35).txt"); // "(34)" in the middle should be ignored
DecomposedFilePath changedSuffix = withExtraNumber.ReplaceSuffix( 1999 ); // "file(34)xyz(35).txt" -> "file(34)xyz(1999).txt"
DecomposedFilePath removedSuffix = changedSuffix.ReplaceSuffix( null ); // "file(34)xyz(1999).txt" -> "file(34)xyz.txt"
var testPath = new DecomposedFilePath( "c:\\test\\file.txt");
DecomposedFilePath nextPath1 = testPath.GetFirstFreeFilePath( testFilePaths );
// update our list
testFilePaths.Add( nextPath1.FullFilePath );
DecomposedFilePath nextPath2 = testPath.GetFirstFreeFilePath( testFilePaths );
testFilePaths.Add( nextPath2.FullFilePath );
DecomposedFilePath nextPath3 = testPath.GetFirstFreeFilePath( testFilePaths );
}
}
public sealed class DecomposedFilePath
{
public DecomposedFilePath( string filePath )
{
FullFilePath = Path.GetFullPath( filePath );
}
// "c:\myfiles\file(4).txt"
public string FullFilePath { get; }
// "file" or "file(1)"
public string FileNameWithoutExt => Path.GetFileNameWithoutExtension( FullFilePath );
// "file(13)" -> "file"
public string FileNameWithoutExtAndSuffix => FileNameWithoutExt.Substring( 0, FileNameWithoutExt.Length - Suffix.Length ); // removes suffix
// ".txt"
public string Extenstion => Path.GetExtension( FullFilePath );
// "c:\myfiles"
public string DirectoryPath => Path.GetDirectoryName( FullFilePath );
// "file(23)" -> "23", file -> stirng.Empty
public string Suffix
{
get
{
// we want to extract suffix from file name, e.g. "(34)" from "file(34)"
// I am not good at regex, but I hope it will work correctly
var regex = new Regex( #"\([0-9]+\)$" );
Match match = regex.Match( FileNameWithoutExt );
if (!match.Success) return string.Empty; // suffix not found
return match.Value; // return "(number)"
}
}
// tranlates suffix "(33)" to 33. If suffix is does not exist (string.empty), returns null (int?)
public int? SuffixAsInt
{
get
{
if (Suffix == string.Empty) return null;
string numberOnly = Suffix.Substring( 1, Suffix.Length - 2 ); // remove '(' from beginning and ')' from end
return int.Parse( numberOnly );
}
}
// e.g. input is suffix: 56 then it changes file name from "file(34)" to "file(56)"
public DecomposedFilePath ReplaceSuffix( int? suffix ) // null - removes suffix
{
string strSuffix = suffix is null ? string.Empty : $"({suffix})"; // add ( and )
string path = Path.Combine( DirectoryPath, FileNameWithoutExtAndSuffix + strSuffix + Extenstion ); // build full path
return new DecomposedFilePath( path );
}
public DecomposedFilePath GetFirstFreeFilePath( IEnumerable<string> filesInDir )
{
var decomposed = filesInDir
// convert all paths to our class
.Select( x => new DecomposedFilePath( x ) )
// pick files only with the same extensionm as our base file, ignore case
.Where( x => string.Equals( Extenstion, x.Extenstion, StringComparison.OrdinalIgnoreCase) )
// pick files only with the same name (ignoring suffix)
.Where( x => string.Equals( FileNameWithoutExtAndSuffix, x.FileNameWithoutExtAndSuffix, StringComparison.OrdinalIgnoreCase) )
// with the same directory
.Where( x => string.Equals( DirectoryPath, x.DirectoryPath, StringComparison.OrdinalIgnoreCase) )
.ToList(); // create copy for easier debugging
if (decomposed.Count == 0) return this; // no name collision
int? firstFreeSuffix = Enumerable.Range( 1, int.MaxValue) // start numbering duplicates from 1
.Select( x => (int?) x) // change to int? because SuffixAsInt is of that type
.Except( decomposed.Select( x => x.SuffixAsInt) ) // remove existing suffixes
.First(); // get first free suffix
return ReplaceSuffix( firstFreeSuffix );
}
public override string ToString() => FullFilePath;
}
}
This is just a string operation; find the location in the filename string where you want to insert the number, and re-construct a new string with the number inserted. To make it re-usable, you might want to look for a number in that location, and parse it out into an integer, so you can increment it.
Please note that this in general this way of generating a unique filename is insecure; there are obvious race condition hazards.
There might be ready-made solutions for this in the platform, I'm not up to speed with C# so I can't help there.
Take a look at the methods in the Path class, specifically Path.GetFileNameWithoutExtension(), and Path.GetExtension().
You may even find Path.GetRandomFileName() useful!
Edit:
In the past, I've used the technique of attempting to write the file (with my desired name), and then using the above functions to create a new name if an appropriate IOException is thrown, repeating until successful.
This method will add a index to existing file if needed:
If the file exist, find the position of the last underscore. If the content after the underscore is a number, increase this number. otherwise add first index. repeat until unused file name found.
static public string AddIndexToFileNameIfNeeded(string sFileNameWithPath)
{
string sFileNameWithIndex = sFileNameWithPath;
while (File.Exists(sFileNameWithIndex)) // run in while scoop so if after adding an index the the file name the new file name exist, run again until find a unused file name
{ // File exist, need to add index
string sFilePath = Path.GetDirectoryName(sFileNameWithIndex);
string sFileName = Path.GetFileNameWithoutExtension(sFileNameWithIndex);
string sFileExtension = Path.GetExtension(sFileNameWithIndex);
if (sFileName.Contains('_'))
{ // Need to increase the existing index by one or add first index
int iIndexOfUnderscore = sFileName.LastIndexOf('_');
string sContentAfterUnderscore = sFileName.Substring(iIndexOfUnderscore + 1);
// check if content after last underscore is a number, if so increase index by one, if not add the number _01
int iCurrentIndex;
bool bIsContentAfterLastUnderscoreIsNumber = int.TryParse(sContentAfterUnderscore, out iCurrentIndex);
if (bIsContentAfterLastUnderscoreIsNumber)
{
iCurrentIndex++;
string sContentBeforUnderscore = sFileName.Substring(0, iIndexOfUnderscore);
sFileName = sContentBeforUnderscore + "_" + iCurrentIndex.ToString("000");
sFileNameWithIndex = sFilePath + "\\" + sFileName + sFileExtension;
}
else
{
sFileNameWithIndex = sFilePath + "\\" + sFileName + "_001" + sFileExtension;
}
}
else
{ // No underscore in file name. Simple add first index
sFileNameWithIndex = sFilePath + "\\" + sFileName + "_001" + sFileExtension;
}
}
return sFileNameWithIndex;
}
I did it like this:
for (int i = 0; i <= 500; i++) //I suppose the number of files will not pass 500
{ //Checks if C:\log\log+TheNumberOfTheFile+.txt exists...
if (System.IO.File.Exists(#"C:\log\log"+conta_logs+".txt"))
{
conta_logs++;//If exists, then increment the counter
}
else
{ //If not, then the file is created
var file = System.IO.File.Create(#"C:\log\log" + conta_logs + ".txt");
break; //When the file is created we LEAVE the *for* loop
}
}
I think this version is not so hard like the others, and It's a straightforward answer for what the user wanted.
If you need just a unique file name, so, how about this?
Path.GetRandomFileName()
I ran into this problem and, since none of the other answers seemed to have solved it in the way I wanted to, I did it on my own.
static string CheckIfFileExists(string filePath)
{
if (File.Exists(filePath))
{
string parentDir = Directory.GetParent(filePath).FullName;
string fileName = new DirectoryInfo(filePath).Name;
string extension = Path.GetExtension(fileName);
fileName = Path.GetFileNameWithoutExtension(fileName);
if (CheckIfFileNameHasIndex(fileName))
{
string strIndex = fileName[(fileName.LastIndexOf('(')+1)..fileName.LastIndexOf(')')]; //range
int index = int.Parse(strIndex);
index++;
fileName = fileName.Substring(0, fileName.LastIndexOf('(')) + "(" + index + ')';
filePath = Path.Combine(parentDir, fileName + extension);
return CheckIfFileExists(filePath);
}
else
{
fileName = fileName + " (1)";
filePath = Path.Combine(parentDir, fileName + extension);
return CheckIfFileExists(filePath);
}
}
return filePath;
}
//checks if filename has an index (e.g. "file(2).jpg")
static bool CheckIfFileNameHasIndex(string fileName)
{
bool isSuccessful = false;
if (fileName.LastIndexOf('(')!=-1 && fileName.LastIndexOf(')')!=-1)
{
string index = fileName[(fileName.LastIndexOf('(')+1)..fileName.LastIndexOf(')')]; //range
int result;
isSuccessful = int.TryParse(index, out result);
}
return isSuccessful;
}
The method CheckIfFileExists is recursive, so in theory it should be able to handle a potentially unlimited number of duplicates (e.g. "file (3484939).txt"). Of course, in reality, what happens is that the maximum imposed filename length of your operating system and stuff like eventually become a bottleneck.
I have written a method that returns "next" file name with number.
Supports numbering from 1 to 99.
Examples:
C:\Recovery.txt → C:\Recovery1.txt
C:\Recovery1.txt → C:\Recovery2.txt
How to call:
while (File.Exists( path ))
path = NextFileNum( path );
internal static string NextFileNum( string path )
{
string filename = Path.GetFileNameWithoutExtension( path );
string ext = Path.GetExtension( path );
string dir = Path.GetDirectoryName( path );
for (int i = 99; i > 0; i--)
{
if (filename.EndsWith( i.ToString() ))
{
string suffix = ( i + 1 ).ToString();
filename = filename.Substring( 0, filename.Length - suffix.Length ) + suffix;
return Path.Combine( dir, filename + ext );
}
}
filename = filename + "1";
return Path.Combine( dir, filename + ext );
}
public static string MakeUniqueFilePath(string filePath)
{
if (!File.Exists(filePath)) return filePath;
var directory = Path.GetDirectoryName(filePath);
var fileName = Path.GetFileNameWithoutExtension(filePath);
var fileExt = Path.GetExtension(filePath);
var i = 1;
do
{
filePath = Path.Combine(directory, fileName + "(" + i + ")" + fileExt);
i++;
} while (File.Exists(filePath));
return filePath;
}
Returns files like so:
test.txt
test(1).txt
test(2).txt
etc.
Notes:
Can handle filenames without extensions
Can Handle directories included in the file path.
Does not handle file creation race conditions when saving.

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