Re: [Qemu-devel] [PATCH V2] Add "tee" option to qemu char device

[Anthony Liguori]

On 07/24/2011 04:47 AM, Alexander Graf wrote:
> > These arguments all apply to any possible option.  Why not a grep target?  Why 
> > not a cut or less target?
>
> Because they don't make sense.

Neither does tee :-)

> > > As long as the tee target is reasonably isolated, I don't think it'd clutter 
> > > the char backend.
> >
> > It'll never be tested and end up becoming dead bloat code.
>
> I'll be extensively tested in Xen code, since that's how Xen will invoke qemu.

If this is being used by Xen as part of Xend, then there's really no 
point in worrying about complexity because the user will never be 
exposed to it.

> I tend to agree, but this time the solution in qemu is cleaner and easier IMHO.

Let's compare the typical use-case:

qemu -hda linux.img -nographic | tee boot.log

vs:

qemu -hda linux.img -serial tee:boot.log,stdio

I'm not even sure I got the syntax right on the later.

> Also, I've had issues with tee several times already.

Then we should fix those issues.  But I have a hard time believing there 
were ever issues.  This is just piping.

> I'm in favor of putting a tee target into qemu's char layer and I'm sure it'll 
> become a well used target.

It will only be used by Xen and Xen could very easily solve this problem 
outside of qemu.

It adds another twisted command line syntax that will make it harder to 
generalize later.

Regards,

Anthony Liguori

> Alex