Hi, I was trying to copy a directory from my school web space, and there was a link in the directory that led back to the directory itself. When I tried to scp this directory to my home computer, scp tried to create an infinite number of copies of the directory! It was someone else's directory, so I couldn't just delete the link. The directory worked fine with "cp -r", but not with "scp -r". I could provide a sample of this kind of directory if that would be helpful. Thanks!
Is that "link" or "symlink"? Hard links to directories are usually the result (or cause!) of filesystem corruption. Show us what it your directory and its link looks like (eg ls -l).
The offending file is named "suzuki". When I "ls -l suzuki" in the directory, it tells me " lrwxr-xr-x 1 8779 staff 1 May 18 1994 suzuki -> . " Thanks.
Right now, scp does not understand symlinks at all, and afaict having it understand them enough to be able to copy them (like "rsync -l") would require a protocol change (which is not going to happen). Maybe we could add an option to scp to skip links ("scp -l" ?) Opinions?
That seems odd, consider that symlinks are so widely used. I haven't been able to find a copy of the SCP protocol online, but I'd be interested in taking a look at it, and making suggestions for how it could be extended. Do you know where there's a copy?
SCP is just the old 'rcp' but uses the ssh instead of rsh for the tunnel. And rcp was never really documnted outside of the source. I don't for see us 'extending' this anytime soon. scp is really just for legacy support to help those that are migrating to ssh. sftp is an RFC standard protocol and all work should be done on that.
(Ben beat me to this, but I'll add my voice anyway) There is no specification of the scp protocol, it is just rcp over ssh. We aren't interested in extending it at all: it is very widely deployed, undocumented, 20+ year old protocol with uncorrectable flaws and no versioning or migration mechanism. It is better to improve the tools of the sftp (draft-ietf-secsh-filexfer-*) protocol instead. This protocol fixes all of the above flaws and includes the ability to recognise and transfer symlinks. Our sftp tools aren't as complete as the scp ones (in particular, there are no recursive commands yet), but that can be rectified :)
*nod* I hadn't really looked at sftp; that makes sense. Do you expect that scp's functionality will eventually be replaced by command-line arguments to sftp? I think it's very convenient to be able to use scp to copy things quickly.
Basically, the spec for scp is "what rcp does", and the spec for rcp is "what some guys at Berkeley wrote in the early 80's". rcp might even predate the existence of symlinks. Like Ben says, the closest thing to a spec for scp is "scp.c". Suggested workarounds: 1) Don't do that, then. 2) Use tar-over-ssh or rsync-over-ssh to transfer it link and all, eg: ssh yourhost 'tar cf - dir-to-copy' | tar xvf - 3) Use sftp (it doesn't do recursive yet, one day it will).
Yes, there is even an open bug for this: Bug #634