oflag option in GNU dd - equivalent in FreeBSD dd ?

[Dan Nelson]

In the last episode (Oct 23), Oliver Fromme said:
> Bahman M. <b.movaqar at adempiere.org> wrote:
>  > On 2007-10-22 Juri Mianovich wrote:
>  > > I am used to using this command in Linux, using GNU
>  > > dd:
>  > > 
>  > > dd if=/blah of=/bleh oflag=append conv=notrunc
>  > > 
>  > > The problem is, FreeBSD 'dd' does not understand the
>  > > "oflag" argument.
>  > > 
>  > > Is there some equivalent in the FreeBSD 'dd' syntax
>  > > that I can use, or am I forced to install GNU utils ?
> 
> Of course, the easiest way is to do this:
> 
> $ dd if=/blah >> /bleh
> 
> If you cannot do that, please explain why.  If you know
> your reason, there might be an alternative way to do it.
> 
>  > dd if=/blah of=/bleh conv=notrunc seek=`ls -s /bleh | cut -f1 -d ' ' -`
>  > 
>  > I don't know if any simpler way is possible (anyone?).
> 
> $ dd if=/blah of=/bleh conv=notrunc seek=$(stat -f%z /bleh)

I don't think that will work, since seek's argument is in blocks.  Even
if you divide by 512 (or whatever you decide to set bs=), if the file
you're appending do isn't a multiple of the blocksize, you'll end up
chopping part of the end off.

-- 
	Dan Nelson
	dnelson at allantgroup.com