This week I helped out my Business Intelligence colleagues again.

After tackling another problem with a regular expression, the end result contained strange characters. In the output below there is a question mark icon where the Pound (£) sign used to be.

"Whatever returned, � 35.00 debited";3;1;"";0;0

The problem is that the system where the code executes uses a different code page. This messes with the encoding. To solve this we used the Enconding.Default as parameter when reading or writing the text file.

string input = File.ReadAllText(sourceFile, Encoding.Default);
// pattern removed for simplicity
string output = Regex.Replace(input, pattern, " ");
File.WriteAllText(destinationFile, output, Encoding.Default);