Including control characters in a .txt file to be read by C#

Question

I'm working on a project that uses a plain ASCII .txt file as a key/value configuration file. The current format for ConfigFile.txt is something like

FirstName=Elmer|LastName=Fudd|UserId=EFudd|Password=fubar|Date=7/29/2016

This is easy to read into the program and create a dictionary with KeyValuePairs with code something like:

   using (FileStream fs = new FileStream("ConfigFile.txt", FileMode.Open))
    {
      using (StreamReader sr = new StreamReader(fs))
      {
        string fileText = sr.ReadToEnd();

        //  Tokenize the entire file string into separate key=value strings.
        string[] tokens = fileText.Split('|');

        //  Iterate through all of the key=value strings, tokenize each one into a key=Value 
        //  pair and add the key and value as separate strings into the dictionary.
        foreach (string token in tokens)
        {
          string[] keyValuePair = token.Split('=');
          configDict.Add(keyValuePair[0], keyValuePair[1]);
        }
      }
    }

It first splits out each key/value as a separate string using the '|' as the delimiter.

FirstName=Elmer

LastName=Fudd

UserId=EFudd

Password=foobar

Date=7/29/2016

Then, for each key/value string, it separates the key and value on the '=' delimiter, creates a KeyValuePair, and inserts it into a dictionary for later lookups in the program.

So far so good. Users are instructed not to create passwords with either delimiter. However, I now have to encrypt the password before including it in the file and the encryption routine can produce any printable character from 0x20 through 0x7F. So, an encrypted password can end up with either or both of the delimiters. I can end up with 'foobar' (or whatever) being encrypted by the encryption engine into P#|=g%. This messes up the ability of the split function to work properly.

So, I want to change the delimiters typed into the Notepad .txt file to control characters so that, instead of the '|' delimiter, I am using 0x1E (Record Separator) and replace the '=' sign with 0x1F (Unit Separator).

I can escape and code this directly in C# with no problems, but how would I modify the original .txt disk file so that it will read in the delimiters as single (non-printable) characters correctly?

Answer 1

Easiest Answer:

Insert the special characters into the string using the ALT-numberpad value trick. Record Group ALT-31 (▼) to delimit the end of a Key/Value pair and Item Group ALT-30 (▲) to delimit the key from the value. Save the string as UTF-8.

Code for delimiters is

private static char tokenDelimiter = ('▲');
private static char keyValuePairDelimiter = ('▼');

using the same ALT-numberpad trick to put in the up and down triangles. Include instructions that the black triangles are NEVER to be edited or removed and explain their meaning.

It takes me back to my old DOS days. Simple, and took 5 minutes to implement - and it doesn't require that the existing code base be materially changed - just the two delimiter characters changed.