Rules for Accessing Other Files

The functions for accessing files, such as fopen, OpenFile, SetFileAttrs, DeleteFile, and so on, interpret relative pathnames as being relative to the current working directory. The initial current working directory is normally the directory of the executable. However, if a different directory exists in the Working Directory or Start In field of the Windows Properties dialog box for the shortcut for the executable, then that directory is the initial current working directory.

(Linux) The initial current working directory is the directory from which you invoke the executable.

You can create an absolute path for a file in the executable directory by using GetProjectDir and MakePathname.