spc restarts

Mark Anderson mark at nosredna.net
Mon Feb 27 04:15:06 EST 2012

Yes, I was thinking of sftp but had forgotten because
I had wanted to ask this question on this list a while
ago but figured I ought to watch the list for a while
first to find out if it was appropriate.

I saw that the server side supported starting in the
middle and I figured that if you had part of the file
locally downloaded it would be easy to start where it
left off.  The same capability that wget has for http

I could use rsync but only if that server was running
on the other end, which is not as likely as sshd.

On 02/26/12 12:09, Ben Lindstrom wrote:
> On Feb 26, 2012, at 9:02 AM, Mark Anderson wrote:
>> I was wondering why scp didn't have a restart-in-the-middle
>> option when transferring a large file.  Isn't that something
>> that is supported by the underlying ssh protocol?  Is there
>> some other program that can give me this functionality ?
> Scp came from rcp.. Which is a stupid simple(ish) protocol
> more like doing:  tar -cvf | ssh tar -xvf.  So it really has nothing
> to do with the ssh protocol itself as it just needs a streaming
> socket to throw data at.
> I suspect you're thinking sftp service, and that could be easily 
> extended to support it.  I did a cheap proof of concept that 
> required adding an sha1 hash request extension to the server 
> so I could determine where I needed to pick up in the transfer.  
> It really was an attempt to implement a simplified rsync over sftp.
> However, that code is long since dead and burned.
> - Ben

More information about the openssh-unix-dev mailing list