How to read particular line from *.txt file?

Question

How can I get a string which is for example in 4th line of a text file? Here's the code I'm using to read/write/edit file:

 import System.IO;
 var filePath = "/Users/testWrite.txt";
 
 function Update(){
     if (Input.GetKeyDown("c")) {
         WriteFile(filePath);
     }
     if (Input.GetKeyDown("w")) {
         AddToFile(filePath);
     }
     if (Input.GetKeyDown("r")) {
         ReadFile(filePath);
     }
 }
 function WriteFile(filepathIncludingFileName : String){
     var sw : StreamWriter = new StreamWriter("testFile.txt");
     sw.WriteLine("Line to write");
     sw.WriteLine("Another Line");
     sw.Flush();
     sw.Close();
 }
 function AddToFile(filepathIncludingFileName : String){
     sr = File.AppendText("testFile.txt");
     sr.WriteLine("Added ");
     sr.Write("Another Line");
     sr.Flush();
     sr.Close();
 }
 function ReadFile(filepathIncludingFileName : String) {
     sr = new File.OpenText("testFile.txt");
     input = "";
     while (true) {
         input = sr.ReadLine();
         if (input == null) { break; }
         Debug.Log("line="+input);
     }
     sr.Close();
 }

Answer 1

Best Answer

Answer by whydoidoit · Jun 23, 2012 at 03:59 PM

You could read the whole file into a list and then you could access any line you like: import System.Collections.Generic; import System.Linq;

   var fileLines : List.<String>;

   function ReadFile() {
      var sr = File.OpenText("whatever.txt");
      fileLines = sr.ReadToEnd().Split("\n"[0]).ToList();
      sr.Close();
   }

Now you have a list of lines that you can insert into, get a specific line from - whatever. If you want to write them back out you can just do:

  var wholeFileText = String.Join("\n", fileLines.ToArray());

Add comment · Show 2 · Share

VKronners · Jan 03, 2017 at 04:51 AM 0

Share

Can you make a C# answer also plz... I'm stuck in the same problem but im using C#...

Ahndrakhul VKronners · Jan 03, 2017 at 07:05 AM 0

Share

The easiest way to read lines of text into a list is probably:

 List<string> fileLines = new List<string>(System.IO.File.ReadAllLines("FILEPATH"));

To write them back (overwriting the old file contents):

 System.IO.File.WriteAllLines("FILEPATH", fileLines.ToArray());

"FILEPATH" would be replaced with whatever the path to your file is.

This is the easiest way as far as I know, but it's not the best performance wise. There's a lot of converting from array to list and back.

How to read particular line from *.txt file?

1 Reply

Your answer

Welcome to Unity Answers

Follow this Question

Related Questions