c# search string in txt file

Question

I want to find a string in a txt file if string compares, it should go on reading lines till another string which I'm using as parameter.

Example:

CustomerEN //search for this string ... some text which has details about the customer id "123456" username "rootuser" ... CustomerCh //get text till this string 

I need the details to work with them otherwise.

I'm using linq to search for "CustomerEN" like this:

File.ReadLines(pathToTextFile).Any(line => line.Contains("CustomerEN")) 

But now I'm stuck with reading lines (data) till "CustomerCh" to extract details.

Answer 1

If your pair of lines will only appear once in your file, you could use

File.ReadLines(pathToTextFile)     .SkipWhile(line => !line.Contains("CustomerEN"))     .Skip(1) // optional     .TakeWhile(line => !line.Contains("CustomerCh")); 

If you could have multiple occurrences in one file, you're probably better off using a regular foreach loop - reading lines, keeping track of whether you're currently inside or outside a customer etc:

List<List<string>> groups = new List<List<string>>(); List<string> current = null; foreach (var line in File.ReadAllLines(pathToFile)) {     if (line.Contains("CustomerEN") && current == null)         current = new List<string>();     else if (line.Contains("CustomerCh") && current != null)     {         groups.Add(current);         current = null;     }     if (current != null)         current.Add(line); } 

Answer 2

You have to use while since foreach does not know about index. Below is an example code.

int counter = 0; string line;  Console.Write("Input your search text: "); var text = Console.ReadLine();  System.IO.StreamReader file =     new System.IO.StreamReader("SampleInput1.txt");  while ((line = file.ReadLine()) != null) {     if (line.Contains(text))     {         break;     }      counter++; }  Console.WriteLine("Line number: {0}", counter);  file.Close();  Console.ReadLine();