Create a file with the same name as the root file but with a .cnx extension. Place the file in the same directory as the data file on the UNIX server. The text file must contain at least three lines; the fourth line is optional.
Line 1 should contain one of the following three words: "sequential", "line", or "relative", depending on the file type;
Line 2 should contain the maximum record length;
Line 3 should contain the minimum record length, and;
Line 4 is optional, but, if used, can signify either fixed or variable length. If the length is variable, the line should contain the word "variable".