C# How to modify text file

Question

I need to read accounts.txt and add/change number after password

Here is accounts.txt

user|password
user1|password1

After starting

user|password|1
user1|password1|1

After closing

user|password|0
user1|password1|0

Sorry for my english

In what pattern do you need these numbers? What have you tried so far? — Georg, Feb 18 '14 at 16:07

score 1 · Accepted Answer · answered Feb 18 '14 at 16:16

1

Add this reference first System.IO Then:

For reading:

string[] accounts= File.ReadAllLines("accounts.txt");
//each item of array will be your account

For modifying :

accounts[0] += "|1";//this adds "|1" near password
accounts[0].Replace("|1","|0"); this will change the "|0" text to "|1"

And For writing:

File.WriteAllLines("accounts.txt",accounts);

answered Feb 18 '14 at 16:16

TC Alper Tokcan

369
1
13

This is it , but how to bypass line with |1.. – user3324218 Feb 18 '14 at 16:24
@user3324218 You can pass the line with using `if()` like : `foreach(string o in accounts){ if(!o.Contains("|1"){ DoWhatYouWant(); })//this means if line not contains "|n" DoWhatYouWant(); ` – TC Alper Tokcan Feb 18 '14 at 16:28
Okey, thanks . I have one more question: I used accounts[5] and i exit programme so i need to change in accounts[5] (|1 to |0) but programme change (|1 to |0) in accounts[1] ... – user3324218 Feb 18 '14 at 16:43
If you Do something like `accounts[5].Replace("|1","|0");` `accounts[1]` will not change look again your code maybe you miss or not see a code that changes `accounts[1]`. – TC Alper Tokcan Feb 19 '14 at 06:58

Habib Rahmoun · Answer 2 · 2014-02-18T16:16:19.053

0

Something like that :

    string[] lines = File.ReadAllLines(@"C:\filepath.txt");
    List<string> newlines = new List<string>();
    foreach(string line in lines)
    {
      string[] temp = line.Split('|');
      newlines.Add(temp[0] + "|" + temp[1] + "|" + "1");
    }

 File.WriteAllLines(@"C:\filepath.txt", newlines.ToArray())

edited Feb 18 '14 at 16:16

answered Feb 18 '14 at 16:10

Habib Rahmoun

218
2
8

Indeed, thx for the correction. – Habib Rahmoun Feb 18 '14 at 16:13
2

And the method returns an array of string `string[] lines`. But good answer though. – Alex Barac Feb 18 '14 at 16:14
One more test needs to be done, specifically, if there acually is a number after the second `'|'`, it only needs to be changed instead of another number being appended to it. – Alex Barac Feb 18 '14 at 16:17

score 0 · Answer 3 · answered Feb 18 '14 at 16:10

Look at System.IO.File class, as well as general System.IO.Stream and System.IO.StreamReader classes.

There are a bunch of examples on the internet on how to read and write text files in .NET: http://msdn.microsoft.com/en-us/library/db5x7c0d(v=vs.110).aspx

C# How to modify text file

3 Answers3