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C#: How to make Stream Reader to Int

I'm reading from a file with numbers and then when I try to convert it to an Int I get this error, System.FormatException: 'Input string was not in a correct format.' Reading the file works and I've tested all of that, it just seems to get stuck on this no matter what I try. This is what I've done so far:
StreamReader share_1 = new StreamReader("Share_1_256.txt");
string data_1 = share_1.ReadToEnd();
int intData1 = Int16.Parse(data_1);
And then if parse is in it doesn't print anything.

As we can see in your post, your input file contains not one number but several. So what you will need is to iterate through all lines of your file, then try the parsing for each lines of your string.
EDIT: The old code was using a external library. For raw C#, try:
using (StringReader reader = new StringReader(input))
{
string line;
while ((line = reader.ReadLine()) != null)
{
// Do something with the line
}
}
In addition, I encourage you to always parse string to number using the TryParse method, not the Parse one.
You can find some details and different implementations for that common problem in C#: C#: Looping through lines of multiline string

parser every single line
while (!reader.EndOfStream)
{
string line = reader.ReadLine();
int intData1 = Int16.Parse(line);
}

You can simplify the code and get rid of StreamReader with a help of File class and Linq:
// Turn text file into IEnumerable<int>:
var data = File
.ReadLines("Share_1_256.txt")
.Select(line => int.Parse(line));
//TODO: add .OrderBy(item => item); if you want to sort items
// Loop over all numbers within file: 15, 1, 48, ..., 32
foreach (int item in data) {
//TODO: Put relevant code here, e.g. Console.WriteLine(item);
}

how can i search a file find a string and get all the text between / /

ok i trying my best to get this string
"/i/models/fc6d6067621442ebb6f4238636363d47/textures?optimized=1"
but i need to get the jumble of numbers and between the // only and save it to a string because each json file i open has a different amount of numbers
i tried using regex but it finds different concordances in the file and i only need the one that matches this line
the file is a json file
https://i.imgur.com/B98gdBD.png
but not sure how to accomplish this
this is the code i tried
List<string> found = new List<string>();
string line;
using (StreamReader file = new StreamReader(Application.StartupPath + "\\textures.json"))
{
while ((line = file.ReadLine()) != null)
{
if (line.Contains("textures?optimized=1"))
{
texturemodel = line;
}
}
}
this code does work and does get the line needed only issue i have with it it has ;} on the end of it so its nearly working but not sure how to remove the white space at the start and the ;{ at the end of the file the white space is at the beginning of the file
thanks in advance elfenliedtopfan5

if you are sure that that would always be the format, try string.Split()
var stringWithJumbledNumbersAndLetters = "/i/models/fc6d6067621442ebb6f4238636363d47/textures?optimized=1";
var splitString = stringWithJumbledNumbersAndLetters.Split('/');
//splitString[0] = i;
//splitString[1] = models;
//splitString[2] = fc6d6067621442ebb6f4238636363d47;
//splitString[3] = textures?optimized=1;
return splitString[2];
or direct would be
var stringWithJumbledNumbersAndLetters = "/i/models/fc6d6067621442ebb6f4238636363d47/textures?optimized=1";
return stringWithJumbledNumbersAndLetters.Split('/')[2];

String s = "/i/models/fc6d6067621442ebb6f4238636363d47/textures?optimized=1";
String[] result = s.split("/");
System.out.println(result[3]);

C# Insert text from one txt file to another txt file

I would like to insert text from one text file to another.
So for example I have a text file at C:\Users\Public\Test1.txt
first
second
third
forth
And i have a second text file at C:\Users\Public\Test2.txt
1
2
3
4
I want to insert Test2.txt into Test1.txt
The end result should be:
first
second
1
2
3
4
third
forth
It should be inserted at the third line.
So far I have this:
string strTextFileName = #"C:\Users\Public\test1.txt";
int iInsertAtLineNumber = 2;
string strTextToInsert = #"C:\Users\Public\test2.txt";
ArrayList lines = new ArrayList();
StreamReader rdr = new StreamReader(
strTextFileName);
string line;
while ((line = rdr.ReadLine()) != null)
lines.Add(line);
rdr.Close();
if (lines.Count > iInsertAtLineNumber)
lines.Insert(iInsertAtLineNumber,
strTextToInsert);
else
lines.Add(strTextToInsert);
StreamWriter wrtr = new StreamWriter(
strTextFileName);
foreach (string strNewLine in lines)
wrtr.WriteLine(strNewLine);
wrtr.Close();
However I get this when i run it:
first
second
C:\Users\Public\test2.txt
third
forth
Thanks in advance!

Instead of using StreamReaders/Writers, you can use methods from the File helper class.
const string textFileName = #"C:\Users\Public\test1.txt";
const string textToInsertFileName = #"C:\Users\Public\test2.txt";
const int insertAtLineNumber = 2;
List<string> fileContent = File.ReadAllLines(textFileName).ToList();
fileContent.InsertRange(insertAtLineNumber , File.ReadAllLines(textToInsertFileName));
File.WriteAllLines(textFileName, fileContent);
A List<string> is way more convenient than an ArrayList. I also renamed a couple of your variables (most notably textToInsertFileName, and removed the prefix cluttering your declarations, any modern IDE will tell you the datatype if you hover for half a second) and declared your constants with const.
Your original problem was related to the fact that you're never reading from strTextToInsert, looks like you thought it was already the text to insert where it's actually the filename.

Without changing your structure or types around too much you could create a method to read the lines
public ArrayList GetFileLines(string fileName)
{
var lines = new ArrayList();
using (var rdr = new StreamReader(fileName))
{
string line;
while ((line = rdr.ReadLine()) != null)
lines.Add(line);
}
return lines;
}
In the intiial question you were not reading the second file, in the following example it is a little easier to determine when you are reading the files and that each one is read:
string strTextFileName = #"C:\Users\Public\test1.txt";
int iInsertAtLineNumber = 2;
string strTextToInsert = #"C:\Users\Public\test2.txt";
ArrayList lines = new ArrayList();
lines.AddRange(GetFileLines(strTextFileName));
lines.InsertRange(iInsertAtLineNumber, GetFileLines(strTextToInsert));
using (var wrtr = new StreamWriter(strTextFileName))
{
foreach (string strNewLine in lines)
wrtr.WriteLine(strNewLine);
}
NOTE: if you wrap a reader or write in a using statement it will automatically close
I haven't tested this and it could be done better, but hopefully this gets you pointed in the right direction. This solution would completely rewrite the first file

Replace a word from a specific line in a text file

I'm working on a little test program to experiment with text files and storing some data in them, and I've stumbled accross a problem when trying to replace a value in a specific line.
This is how the formatting of my text file is done :
user1, 1500, 1
user2, 1700, 17
.. and so on.
This is the code I am using at the moment to read the file line by line :
string line;
Streamreader sr = new Streamreader(path);
while ((line = sr.ReadLine()) != null)
{
string[] infos = line.Split(',');
if (infos[0] == username) //the username is received as a parameter (not shown)
//This is where I'd like to change the value
}
Basically, my objective is to update the number of points (the second value in the text line - infos[1]) only if the username matches. I tried using the following code (edited to match my informations)
string text = File.ReadAllText("test.txt");
text = text.Replace("some text", "new value");
File.WriteAllText("test.txt", text);</pre>
The problem with this is that it will replace every corresponding value in the text file, and not just the one of the correct line (specified by the matching username). I know how to change the value of infos[1] (ex: 1500 for user1) but I don't know how to rewrite it to the file after that.
I've searched online and on StackOverflow, but I couldn't find anything for this specific problem where the value is only to be modified if it's on the proper line - not anywhere in the text.
I run out of ideas on how to do this, I would really appreciate some suggestions.
Thank you very much for your help.

Try this:
var path = #"c:\temp\test.txt";
var originalLines = File.ReadAllLines(path);
var updatedLines = new List<string>();
foreach (var line in originalLines)
{
string[] infos = line.Split(',');
if (infos[0] == "user2")
{
// update value
infos[1] = (int.Parse(infos[1]) + 1).ToString();
}
updatedLines.Add(string.Join(",", infos));
}
File.WriteAllLines(path, updatedLines);

use ReadLines and LINQ:
var line = File.ReadLines("path")
.FirstOrDefault(x => x.StartsWith(username));
if (line != null)
{
var parts = line.Split(',');
parts[1] = "1500"; // new number
line = string.Join(",", parts);
File.WriteAllLines("path", File.ReadLines("path")
.Where(x => !x.StartsWith(username)).Concat(new[] {line});
}

How to read a csv file one line at a time and replace/edit certain lines as you go?

I have a 60GB csv file I need to make some modifications to. The customer wants some changes to the files data, but I don't want to regenerate the data in that file because it took 4 days to do.
How can I read the file, line by line (not loading it all into memory!), and make edits to those lines as I go, replacing certain values etc.?

The process would be something like this:
Open a StreamWriter to a temporary file.
Open a StreamReader to the target file.
For each line:
Split the text into columns based on a delimiter.
Check the columns for the values you want to replace, and replace them.
Join the column values back together using your delimiter.
Write the line to the temporary file.
When you are finished, delete the target file, and move the temporary file to the target file path.
Note regarding Steps 2 and 3.1: If you are confident in the structure of your file and it is simple enough, you can do all this out of the box as described (I'll include a sample in a moment). However, there are factors in a CSV file that may need attention (such as recognizing when a delimiter is being used literally in a column value). You can drudge through this yourself, or try an existing solution.
Basic example just using StreamReader and StreamWriter:
var sourcePath = #"C:\data.csv";
var delimiter = ",";
var firstLineContainsHeaders = true;
var tempPath = Path.GetTempFileName();
var lineNumber = 0;
var splitExpression = new Regex(#"(" + delimiter + #")(?=(?:[^""]|""[^""]*"")*$)");
using (var writer = new StreamWriter(tempPath))
using (var reader = new StreamReader(sourcePath))
{
string line = null;
string[] headers = null;
if (firstLineContainsHeaders)
{
line = reader.ReadLine();
lineNumber++;
if (string.IsNullOrEmpty(line)) return; // file is empty;
headers = splitExpression.Split(line).Where(s => s != delimiter).ToArray();
writer.WriteLine(line); // write the original header to the temp file.
}
while ((line = reader.ReadLine()) != null)
{
lineNumber++;
var columns = splitExpression.Split(line).Where(s => s != delimiter).ToArray();
// if there are no headers, do a simple sanity check to make sure you always have the same number of columns in a line
if (headers == null) headers = new string[columns.Length];
if (columns.Length != headers.Length) throw new InvalidOperationException(string.Format("Line {0} is missing one or more columns.", lineNumber));
// TODO: search and replace in columns
// example: replace 'v' in the first column with '\/': if (columns[0].Contains("v")) columns[0] = columns[0].Replace("v", #"\/");
writer.WriteLine(string.Join(delimiter, columns));
}
}
File.Delete(sourcePath);
File.Move(tempPath, sourcePath);

memory-mapped files is a new feature in .NET Framework 4 which can be used to edit large files.
read here http://msdn.microsoft.com/en-us/library/dd997372.aspx
or google Memory-mapped files

Just read the file, line by line, with streamreader, and then use REGEX! The most amazing tool in the world.
using (var sr = new StreamReader(new FileStream(#"C:\temp\file.csv", FileMode.Open)))
{
var line = sr.ReadLine();
while (!sr.EndOfStream)
{
// do stuff
line = sr.ReadLine();
}
}