CARTER@MITBATES.BITNET (04/06/88)
You can find the capability you need in the IO Reference Guide Part I under the "ACP-QIO Interface" chapter. You will want to look at section 1.3.5 Read/Write Attributes. Tony Carter MIT Bates Linac CARTER@MITBATES.BITNET
nagy%warner.hepnet@LBL.GOV (Frank J. Nagy, VAX Wizard & Guru) (04/09/88)
> i would like to know if someone knews a method to set file file attribute > NOBACKUP from *inside* a program. It should be the same as SET FILE/NOBACKUP. > I've scanned the RMS manual, but didn't find any hint how to do this. > May be it's DEC's secret, because this piece of information is hidden in the > directory file. The documentation you want to look at is the I/O User's Guide, Part I about the ACP-QIO interface for the file system. What you want to do is use Write Attributes to write the 32-bit file characteristics (ATR$C_UCHAR documented on page 1-18). The bit definitions are documented on page 1-21 (FCNNOBACKUP is really FCH$M_NOBACKUP). The VAX C header files ATRDEF.H defines the attribute (ATR$C...) codes, FIBDEF.H the File Information Block and FCHDEF.H the file characteristics bits. The NOBACKUP flag bit is in the file characteristics longword in the file header (not in the directory). = Frank J. Nagy "VAX Guru & Wizard" = Fermilab Research Division EED/Controls = HEPNET: WARNER::NAGY (43198::NAGY) or FNAL::NAGY (43009::NAGY) = BitNet: NAGY@FNAL = USnail: Fermilab POB 500 MS/220 Batavia, IL 60510