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C# Regular expression To replace all matches in the string

I Have one text file and I want to replaces all matches in each line, so I defined Pattern and I loop through to the text file after I want to write the result in another file, unfortunately my pattern is only replace first occurrence of the word what did |I do in a wrong way?
Content of text file:
"testebook kok o testebook\ntestbbb1232 joj ds testbbb1232"
using System.Text.RegularExpressions;
string filePath = "test.txt";
string fileNewPath = "test1.txt";
string ma = #"^test[0-9a-zA-Z]+";
string newString = string.Empty;
using(StreamReader sr = new(filePath)){
string line = sr.ReadLine();
while (line != null){
while(Regex.IsMatch(line, ma) != false){
line = Regex.Replace(line, ma, "");
}
newString += line + "\n";
line = sr.ReadLine();
}
}
using(StreamWriter sw = new(fileNewPath)){
sw.WriteLine(newString);
}

Your code is correct but your regex pattern is not correct.
you should write this:
string ma = #"test[0-9a-zA-Z]+";
The letter "^" has removed from pattern

So I modified My pattern and remove start with character and everything works now as desired
using System.Text.RegularExpressions;
string filePath = "test.txt";
string fileNewPath = "test1.txt";
MatchesFinder test = new(filePath, fileNewPath);
test.RunTheProcess();
class MatchesFinder{
private string filePath;
private string fileNewPath;
private string ma = #"test[a-zA-Z0-9]+";
public MatchesFinder(string filePath,string fileNewPath){
this.filePath = filePath;
this.fileNewPath = fileNewPath;
}
public void RunTheProcess(){
string newString = string.Empty;
using(StreamReader sr = new(filePath)){
string line = sr.ReadLine();
while (line != null){
while(Regex.IsMatch(line, ma) != false){
line = Regex.Replace(line, ma, string.Empty);
}
newString += line.TrimStart() + "\n";
line = sr.ReadLine();
}
}
using(StreamWriter sw = new(fileNewPath)){
sw.WriteLine(newString);
}
}
}

I think you don´t need to check IsMatch separately, just calling Regex.Replace should yield the same result.
Also, newString += line.TrimStart() + "\n"; means you´re copying all the lines you´ve already checked every time you append a new line. I´d either write directly to the output stream or at least use a StringBuilder if you really want to have the full file in memory for some reason.
Something like this:
using var sw = new StreamWriter(fileNewPath);
using var sr = new StreamReader(filePath);
var line = sr.ReadLine();
while (line != null){
line = Regex.Replace(line, ma, string.Empty);
sw.WriteLine(line.TrimStart());
line = sr.ReadLine();
}

read .csv file into 1D array c#

I would like to convert this code from java to C#
I need to write line by line from csv and store it in an array?
String csvFile = "data.csv";
String line = "";
String cvsSplitBy = ",";
try (BufferedReader br = new BufferedReader(new FileReader(csvFile)))
{
while ((line = br.readLine()) != null)
{
// use comma as separator
String[] data = line.split(cvsSplitBy);
System.out.println(Integer.parseInt(data[0]) + " "+data[1] + " "+data[2] );
}
}
catch (IOException e)
{
e.printStackTrace();
}
Any suggestions?

If you are trying to parse each record/row into array, this might help.
using (StreamReader sr = new StreamReader("maybyourfilepat\data.csv"))
{
string line = sr.ReadLine();
//incase if you want to ignore the header
while (line != null)
{
string[] strCols = line.Split(',');
line = sr.ReadLine();
}
}

Get text using Regex and line number

I need to find strings as follows in a file:
_["Some text"];
or
_.Plural(1, "Some text", "Some text plural);
I am looping file text lines using:
using (StreamReader reader = File.OpenText(file)) {
String line;
while ((line = reader.ReadLine()) != null) {
}
}
In each line I need to get:
"Some text"
OR
"Some text", "Some text plural"
And in both cases I need to get the line number inside the file for each instance.
How can I do with Regex?

Using the pattern and logic from these SO posts:
https://stackoverflow.com/a/171483/1634205
https://stackoverflow.com/a/4892517/1634205
And following this tutorial:
https://www.dotnetperls.com/regex-file
Try this:
static void Main(string[] args)
{
Regex pattern = new Regex("\"(.*?)\"");
string file = #"C:\where\your-file\is\file.txt";
using (StreamReader reader = File.OpenText(file))
{
string line;
while ((line = reader.ReadLine()) != null)
{
foreach (Match match in pattern.Matches(line))
{
Console.WriteLine(match.Value);
}
}
}
Console.ReadLine();
}

find a line and read/display the next line in text document C#

I have this code so far. It looks through a text document and displays lines with the word word in them. I want to make it skip that line and display the next one in the text document, how do I do that?
e.g. it looks thought the text document and finds a line with the word "word" in it and then displays the line that comes after it no other line
string line;
// Read the file and display it line by line.
System.IO.StreamReader file = new System.IO.StreamReader("test.txt");
while ((line = file.ReadLine()) != null)
{
if (line.Contains("word"))
{
Console.WriteLine(line);
}
}
file.Close();

If you're trying to write the line following an occurence of word in a line, try this:
int counter = 0;
bool writeNextLine = false;
string line;
// Read the file and display it line by line.
System.IO.StreamReader file = new System.IO.StreamReader("test.txt");
while ((line = file.ReadLine()) != null)
{
if (writeNextLine)
{
Console.WriteLine(line);
}
writeNextLine = line.Contains("word");
counter++;
}
file.Close();

Something like this will show all the lines except empty lines and lines with the word "word"
using (var rdr = new StreamReader(#"C:\Users\Gebruiker\Desktop\text.txt"))
{
while (!(rdr.EndOfStream))
{
var line = rdr.ReadLine();
if (!(line.Contains("word")) && (line != String.Empty))
{
Console.WriteLine(line);
}
}
}
Console.ReadKey();

This should display all lines after those that contain "word".
int counter = 0;
string line;
System.IO.StreamReader file = new System.IO.StreamReader("test.txt");
while ((line = file.ReadLine()) != null)
{
if (line.Contains("word"))
{
if ((line = file.ReadLine()) != null)
Console.WriteLine(line);
}
counter++;
}
file.Close();

reading html file and display in CKEditor

I am currently using CKEditor for my project to read and display the content of a html file.
However, instead of getting the content of the file, all I get is a string: < html > display in the editor.
But if I write the content directly to the page using response.write, then all the content of the file is displayed correctly.
this is the code snippet I used to read the file:
strPathToConvert = Server.MapPath("~/convert/");
object filetosave = strPathToConvert + "paper.htm";
StreamReader reader = new StreamReader(filetosave.ToString());
string content = "";
while ((content = reader.ReadLine()) != null)
{
if ((content == "") || (content == " "))
{ continue; }
CKEditor1.Text = content;
//Response.Write(content);
}
Can anybody help me to solve this problem?
Many Thanks.

You are in a while loop and you are overwriting the contents of CKEditor every time since you use = instead of +=. Your loops should be:
StreamReader reader = new StreamReader(filetosave.ToString());
string content = "";
while ((content = reader.ReadLine()) != null)
{
if ((content == "") || (content == " "))
{ continue; }
CKEditor1.Text += content;
//Response.Write(content);
}
a better way would probably be to use
string content;
string line;
using (StreamReader reader = new StreamReader(filetosave.ToString())
{
while ((line= reader.ReadLine()) != null)
{
content += line;
}
}
CKEditor1.Text = content;