To search the GSD files, begin with a call to GsFindFirstStreet. This function sets the locale and filtering options, as well as returns a street handle for the first street. The next call is normally to GsFindFirstSegment, which takes as an argument the street handle received from GsFindFirstStreet promoted to a segment handle, as detailed in Street, segment, and range handles. Often developers use a series of three nested while statements to traverse all possible entries.