Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!columbia!rutgers!lll-lcc!ames!ucbcad!ucbvax!uvacs.UUCP!uucp
From: uucp@uvacs.UUCP (UNIX-to-UNIX Copy)
Newsgroups: comp.os.vms
Subject: Submission for mod-computers-vax
Message-ID: <8704261025.AA05812@uvacs.cs.virginia.edu>
Date: Sun, 26-Apr-87 06:25:37 EDT
Article-I.D.: uvacs.8704261025.AA05812
Posted: Sun Apr 26 06:25:37 1987
Date-Received: Sat, 2-May-87 10:16:06 EDT
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: world
Organization: The ARPA Internet
Lines: 33

Path: uvacs!virginia!umd5!brl-adm!seismo!esosun!ucsdhub!sdcsvax!ucbvax!AMES-IO.ARPA!SERAFINI%RAL
From: SERAFINI%RAL@AMES-IO.ARPA
Newsgroups: mod.computers.vax
Subject: VMS/RMS question
Message-ID: <8704250736.AA09643@ucbvax.Berkeley.EDU>
Date: 23 Apr 87 21:33:08 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: world
Organization: The ARPA Internet
Lines: 22

info-vaxers,

I feel foolish for asking this question, but I've looked everywhere I know
and can't find a solution.  

How can I find out if a file is readable or writable given the current
process' priveleges?  I've tried F$File_Attributes to get the protection
string, but I found the gotcha that a file can have read protection set,
but the directory file that contains the file doesn't. Obviously, having to
check read protection on every directory in the path is a real hassle,
especially from DCL.  Is there some system service I don't know about
that combines all the processing necessary to achieve this? I know it's
non-trivial, and I assume that it's been done but I just haven't learned
yet.  The problem also exists for trying to write files.  Is there a better
solution than opening the file and testing for failure?

Thanks much.
Dave Serafini
Sterling Software 
NASA/Ames Research Center

serafini%ral@ames-io.arpa   or RAL::SERAFINI (SPAN node 24.6)