CODEWITHSUNDEEP
c#
James
James

Reputation: 16349

Replacing a certain word in a txt file

Following requirements we have users, their passwords and their profile picture stored in a .txt file. A user can be redirected to a profile modification page where they can change their password and/or password picture.

I need to replace the password and/or profile picture name in the .txt file when the user clicks OK.

The users.txt file is laid out like:

mike mike Avatar1
jessica123 123jessica Avatar4
mohd MoHd Avatar3
xiao AxiaoA Avatar2
anna abcANNAabc Avatar1

After doing some research i've tried using:

userFilePath = userFilePath.Replace(Session["password"].ToString(),
                                    passwordTextBox.Text);

The original password is stored on log-in, through the session variable which I was using to find the original text in the file.

But this doesn't work. I'm pretty new to c#. Any help would be appreciated.

Upvotes: 0

Views: 276

Answers (3)

Rob
Rob

Reputation: 517

If at all possible you should take the advice of the comments on your question and not do this in this manner.

If for some reason that is not possible, then here is a place to get started. You want to load the entire file from the file system into memory during a load phase, generally when your application starts, or first has need of the data.

Once the data is in some structure in memory you can alter like you would alter any object in C#.

Once the changes to the memory are done, you would write the entire thing back out to the file, overwriting the old file.

So your question is a very large one, there is the question of how do you read data from a file? How do you create a data structure in memory to hold this particular set of data? And how do you write the data back out to a file? I'd suggest working on one at a time in that order.

Oh and if you can't have a database, but you can change the file format, switch it to XML or JSON and the process of taking it from a file to memory, and back to a file will be much easier.

Upvotes: 0

Hadi Eskandari
Hadi Eskandari

Reputation: 26444

Other than storing information in plain text files and saving passwords in clear text which others already mentioned as a bad idea, I think it is best to void direct string modification on the file level. It is best to abstract this away in a (list of) object and the modify the object and save it back to disk. You can easily do this using a library named FileHelpers, if you still want to use plain text files, without reinventing the wheel.

Also thing to consider, if you insist keeping this on a text file, is to switch to a better structured text file like JSON or XML format. You wouldn't need to use the above mentioned library anymore as .NET already comes with de/serializers for both.

Upvotes: 1

James from CppDepend Team
James from CppDepend Team

Reputation: 799

Be careful you have to change only the line concerned, many users could have the same passeword, so you have to read the file by line , identify the login concerned and of course not replace anything because also the login or avatar could has the same value as the password, but recreate the line with the new info, and after save the file with the new whole text value.

And just an advice for such needs it's better to use relational database.

Upvotes: 2

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