How to read existing text files without defining path

Solution 1:

You could use Directory.GetCurrentDirectory:

var path = Path.Combine(Directory.GetCurrentDirectory(), "\\fileName.txt");

Which will look for the file fileName.txt in the current directory of the application.

Solution 2:

If your application is a web service, Directory.CurrentDirectory doesn't work.

Use System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, "yourFileName.txt")) instead.

Solution 3:

When you provide a path, it can be absolute/rooted, or relative. If you provide a relative path, it will be resolved by taking the working directory of the running process.

Example:

string text = File.ReadAllText("Some\\Path.txt"); // relative path

The above code has the same effect as the following:

string text = File.ReadAllText(
    Path.Combine(Environment.CurrentDirectory, "Some\\Path.txt"));

If you have files that are always going to be in the same location relative to your application, just include a relative path to them, and they should resolve correctly on different computers.

Solution 4:

You need to decide which directory you want the file to be relative to. Once you have done that, you construct the full path like this:

string fullPathToFile = Path.Combine(dir, fileName);

If you don't supply the base directory dir then you will be at the total mercy of whatever happens to the working directory of your process. That is something that can be out of your control. For example, shortcuts to your application may specify it. Using file dialogs can change it.

For a console application it is reasonable to use relative files directly because console applications are designed so that the working directory is a critical input and is a well-defined part of the execution environment. However, for a GUI app that is not the case which is why I recommend you explicitly convert your relative file name to a full absolute path using some well-defined base directory.

Now, since you have a console application, it is reasonable for you to use a relative path, provided that the expectation is that the files in question will be located in the working directory. But it would be very common for that not to be the case. Normally the working directory is used to specify where the user's input and output files are to be stored. It does not typically point to the location where the program's files are.

One final option is that you don't attempt to deploy these program files as external text files. Perhaps a better option is to link them to the executable as resources. That way they are bound up with the executable and you can completely side-step this issue.