Create a Command-based (i.e. console) application

Question

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the application ask for user name and password. The application matches the login name and password from the already saved login names and their password given in a text file called “login.txt”. If the user name and password are correct then the application { do something ....}

I don't want to use contain, If I wrote in the textfile in this format, username:password, how can replace that instead of contain ???

C#

using (StreamReader sr = File.OpenText("E:\\login.txt"))
               {
                   string[] lines = File.ReadAllLines("E:\\login.txt");

                   {

                       if (lines.Contains(Username) && lines.Contains(Password))
                       {
                          .......
                       }

Posted 31-Oct-15 9:30am

R.M49

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Comments

PIEBALDconsult 31-Oct-15 15:52pm

Better to use XML. And encrypt the password as well.

R.M49 31-Oct-15 15:58pm

It is required to do it in this way, it is only for practise

BillWoodruff 31-Oct-15 16:12pm

If we do your homework for you, you will learn nothing.

2 solutions

Solution 1

C#

class Foo
{
    static void Main(string[] args)
    {
        string text = File.ReadAllText("E:\\login.txt");

        string[] temp = text.Trim().Split(':');

        string username = temp[0];
        string password = temp[1];
        
        if(username == Username && password == Password)
        {
           //do stuff
        }
    }
}

Posted 31-Oct-15 9:38am

petarpetrovt

Updated 31-Oct-15 19:07pm

v2

Comments

R.M49 31-Oct-15 15:57pm

where is the if statement ??? how can I check if it matches the textfile or not

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Patrice T · Accepted Answer · 2015-10-31T10:29:00

.Contains is not the problem.
The problem of this code is that, the way you have done it, any string that is in login.txt will match as a username and as a password.
So if Username="a" and Password="a", it will be probably accepted by your code.
To ensure that you match a Username and matching Password, you need to check line by line

C#

foreach (string Line in Lines) {
    // Check Username and password
}

then split the Line in its components.

C#

foreach (string Line in Lines) {
    string[] Parts= Line.Split(",");
    // Check Username and password
}

then check Username with Parts[0] and Password with Parts[1].

C#

UserFound= False;
foreach (string Line in Lines) {
    string[] Parts= Line.Split(",");
    // Check Username and password
    if (Username == Parts[0] && Password == Parts[1]) {
        UserFound= True;
        break;
    }
if (UserFound) {
    // do what you need
}
}