Guardian Procedure Calls Reference Manual

Example
! The following code causes the names of all open files and
! the process handles of the primary and backup openers to be
! returned for the volume identified by search^name:length.
tag := 0;
DO
BEGIN
error := FILE_GETOPENINFO_ ( search^name:length, tag,
pri^opener, back^opener,,,,
name:max^namelen );
END;
UNTIL error <> 0; ! error 0 means success & more opens !
! left; call again !
IF error <> 1 THEN ! error 1 means no more opens !
BEGIN
-- handle error
END;
442 Guardian Procedure Calls (F)