How to add new line into txt file

Question

I'd like to add new line with text to my date.txt file, but instead of adding it into existing date.txt, app is creating new date.txt file..

TextWriter tw = new StreamWriter("date.txt");

// write a line of text to the file
tw.WriteLine(DateTime.Now);

// close the stream
tw.Close();

I'd like to open txt file, add some text, close it, and later after clicking something: open date.txt, add text, and close it again.

So i can get:

Button pressed: txt opened -> added current time, then close it. Another button pressed, txt opened -> added text "OK", or "NOT OK" in the same line, then close it again.

So my txt file will look like that:

2011-11-24 10:00:00 OK
2011-11-25 11:00:00 NOT OK

How can i do this? Thanks!

Marco · Accepted Answer · 2011-11-24T10:34:54.033

298

You could do it easily using

File.AppendAllText("date.txt", DateTime.Now.ToString());

If you need newline

File.AppendAllText("date.txt", 
                   DateTime.Now.ToString() + Environment.NewLine);

Anyway if you need your code do this:

TextWriter tw = new StreamWriter("date.txt", true);

with second parameter telling to append to file.
Check here StreamWriter syntax.

edited Nov 24 '11 at 10:34

answered Nov 24 '11 at 10:27

Marco

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If you're using c# 4 (or newer) compiler, you can put `new StreamWriter("date.txt", append:true)` to make the intention a little clearer. – kͩeͣmͮpͥ ͩ Nov 24 '11 at 10:34

Asken · Answer 2 · 2011-11-24T12:29:34.237

25

No new line:

File.AppendAllText("file.txt", DateTime.Now.ToString());

and then to get a new line after OK:

File.AppendAllText("file.txt", string.Format("{0}{1}", "OK", Environment.NewLine));

edited Nov 24 '11 at 12:29

answered Nov 24 '11 at 10:30

Asken

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Please use `Environment.Newline` and not `"\r\n"` - not every system agrees on how newlines work: https://en.wikipedia.org/wiki/Newline#Representations – kͩeͣmͮpͥ ͩ Nov 24 '11 at 10:32

score 13 · Answer 3 · answered Dec 20 '16 at 23:50

13

Why not do it with one method call:

File.AppendAllLines("file.txt", new[] { DateTime.Now.ToString() });

which will do the newline for you, and allow you to insert multiple lines at once if you want.

answered Dec 20 '16 at 23:50

kad81

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I prefer this to the accepted answer; you don't need to specify new line – twoleggedhorse Jul 13 '18 at 14:54

score 3 · Answer 4 · answered May 28 '17 at 07:18

3

var Line = textBox1.Text + "," + textBox2.Text;

File.AppendAllText(@"C:\Documents\m2.txt", Line + Environment.NewLine);

answered May 28 '17 at 07:18

Mehdi

31
4

score 1 · Answer 5 · answered Oct 16 '21 at 14:51

Try the following code to create and write content to a text file in Unity3D.

void CreateLog() {
        string timestamp = DateTime.Now.ToString("dd-mm-yyyy_hh-mm-ss");
        PlayerPrefs.SetString("timestamp", timestamp);
        string path = Application.persistentDataPath + "/" + "log_" + timestamp + ".txt";
        // This text is added only once to the file.
        if (!File.Exists(path)) {
            // Create a file to write to.
            using (StreamWriter sw = File.CreateText(path))
            {
                sw.WriteLine(DateTime.Now.ToString() + ": " + "App initialised");
            }   
        } else {
            // This text is always added, making the file longer over time
            // if it is not deleted.
            using (StreamWriter sw = File.AppendText(path)) {
                sw.WriteLine(DateTime.Now.ToString() + ": " + "App initialised");
            }   
        }

        // Open the file to read from.
        using (StreamReader sr = File.OpenText(path)) {
            string line = "";
            while ((line = sr.ReadLine()) != null)
            {
                Debug.Log(line);
            }
        }
}

How to add new line into txt file

5 Answers5

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