Returns a legal file name that can be used to create temporary files.
SYS(3) returns file names that begin with numbers. If your code uses SYS(3) with commands such as CREATE TABLE, CREATE CURSOR, SELECT INTO CURSOR, the code may fail because FoxPro cursors or alias names cannot begin with numbers. You can use SYS(2015) instead.
SYS(3) may return a non-unique name when issued successively on a fast computer.