isfd | isam file descriptor |
ISTRUE, or ISFALSE, in which case the error code is returned by isErrno, or found in isfd->iserrno
this routine checks the data file itself against the data file free list in the index file for errors, and will return a value with the following bits set in accordance with it's findings:
IC_DATREAD 0 data file read error IC_BADDATA 1 data record corrupt IC_DATFREE 2 data free list is corrupt
if the return value is zero then no errors were detected.