How to use scp using sudo ?

I am trying to doing scp a file from remote host to local location, file in the remote host has permission -rwx------ and owned by root and also permision in local directory has drwx------ and owned by root. I am trying to do like this to do a scp using ..


sudo scp hostname:/path/to/file.txt /destination/file.txt

but it doesn't seems to work.. as I can't read file on the remote host. How can I achieve it?
beer9Asked:
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woolmilkporcCommented:
Hi,
 
 your example above should work without a problem! What is the exact  error message you get?

 wmp
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beer9Author Commented:
It is asking me the root user's password of the remote host
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TintinCommented:
Assuming you have set up ssh keys for the root users, then the reason the sudo doesn't work is that your HOME directory isn't changed when you sudo so ssh/scp can't find the root ssh keys.

There is the sudo -i option to simulate logging in as the user, but probably better to use

scp -i /root/.ssh/id_dsa root@hostname:/path/to/file.txt /destination/file.txt

Note, if you are on a Unix flavour where root's home dir is /, change

/root/.ssh/id_dsa root

to

/.ssh/id_dsa root
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woolmilkporcCommented:
Well,
 
 I rather assume that root himself is not allowed (and cannot be allowed) to  ssh to hostname without password (ssh keys).

We could try a multi-step process to achieve what you want.

1) Use ssh and sudo to get the file in question to a readable (non-root) remote location and state.
2) Use just scp to copy the inermediate file to a local directory writeable for you (non-root), then delete it.
3) Use sudo locally to move the file to the final local destination and set appropriate permissions.

1,2) ssh -tt hostname "sudo cp /path/to/file.txt /tmp ; sudo chmod o+r /tmp/file.txt ; scp /tmp/file.txt myhost:/tmp; rm /tmp/file.txt"
3) sudo mv /tmp/file.txt /destination/file.txt ; sudo chmod o-r /destination/file.txt

"myhost" is your local host, "hostname" is the remote host!

Looks very unelegant, but for the moment I see no better way with scp.
 
wmp
 



 

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woolmilkporcCommented:
... seems I missed "sudo" in front of the final "rm" in step (1,2). Sorry!
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beer9Author Commented:
Thank you :-)
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