From mboxrd@z Thu Jan  1 00:00:00 1970
Message-Id: <200103281926.f2SJQnl94482@orthanc.ab.ca>
From: Lyndon Nerenberg <lyndon@orthanc.ab.ca>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] 9fs/9auth for FreeBSD 
In-reply-to: Your message of "Tue, 27 Mar 2001 22:46:03 EST."
             <20010328034613.20C2F199ED@mail.cse.psu.edu> 
Date: Wed, 28 Mar 2001 12:26:49 -0700
Topicbox-Message-UUID: 760e9082-eac9-11e9-9e20-41e7f4b1d025

>>>>> "Russ" == Russ Cox <rsc@plan9.bell-labs.com> writes:

    Russ> the biggest shortcoming
    Russ> is the lack of a portable way to implement append-only
    Russ> files.  freebsd (and presumably the other unix clones) take
    Russ> append-only to mean "only appends succeed" rather than "all
    Russ> writes are treated as appends", and there's no standard way
    Russ> to enable even this.

On 4.4BSD-derived systems you should be able to get the behaviour you
want with chflags(path, UF_APPEND) after creating the file.  During
subsequent opens you would have to check for this flag, and open with
O_APPEND if it is present (to force the writes to always be treated as
appends). Did you try this? (I realize it's not very portable.)

Without chflags() you would have to hijack on of the mode bits, which
is downright evil.

--lyndon