From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <49c8e5f6ae1f50391b40e6465b4a8818@plan9.jp>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] non-truncating create
From: Joel “chesky” Salomon <JoelCSalomon@Gmail.com>
Date: Mon,  9 Oct 2006 02:09:54 -0400
In-Reply-To: <ee9e417a0610082100n256719c6j568ce455859414e@mail.gmail.com>
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> Rc just tries the open, and if that fails, tries the create.
> It doesn't even bother looking at the error code.
> If the open failed due to permissions, so will the create.

Drawterm barfed on me and I lost the bit of code this suggested; when
I tried to recreate it I ended up checking for OTRUNC a few times.
Not pretty.

> Or use create with OEXCL if you really care.

Sort of the way create(2) calls create(5) first, then open(5) if that
failed?  My code now looks like:
	o =3D create(oname, omode|OEXCL, ~0);	/* fails if file exists */
	if(o < 0)
		o =3D open(oname, omode);
	if(o < 0){
		complain("can=E2=80=99t open %s for writing: %r", oname);
		return;
	}
which has no special-case code depending on OTRUNC being set or no.

I suppose I ought to look at /sys/src/cmd/rc to see how it=E2=80=99s real=
ly
done.  Ma=C3=B1ana.

Thanks for the assist.

--Joel