How to scp back to local when I've already sshed into remote machine?
Given that you have an sshd
running on your local machine, it's possible and you don't need to know your outgoing IP address. If SSH port forwarding is enabled, you can open a secure tunnel even when you already have an ssh connection opened, and without terminating it.
Assume you have an ssh connection to some server:
local $ ssh [email protected]
Password:
remote $ echo abc > abc.txt # now we have a file here
OK now we need to copy that file back to our local server, and for some reason we don't want to open a new connection. OK, let's get the ssh command line by pressing Enter ~C
(Enter, then tilde, then capital C):
ssh> help
Commands:
-L[bind_address:]port:host:hostport Request local forward
-R[bind_address:]port:host:hostport Request remote forward
-D[bind_address:]port Request dynamic forward
-KR[bind_address:]port Cancel remote forward
That's just like the regular -L/R/D
options. We'll need -R
, so we hit Enter ~C
again and type:
ssh> -R 127.0.0.1:2222:127.0.0.1:22
Forwarding port.
Here we forward remote server's port 2222 to local machine's port 22 (and here is where you need the local SSH server to be started on port 22; if it's listening on some other port, use it instead of 22).
Now just run scp
on a remote server and copy our file to remote server's port 2222 which is mapped to our local machine's port 22 (where our local sshd
is running).
remote $ scp -P2222 abc.txt [email protected]:
[email protected]'s password:
abc.txt 100% 4 0.0KB/s 00:00
We are done!
remote $ exit
logout
Connection to example.com closed.
local $ cat abc.txt
abc
Tricky, but if you really cannot just run scp
from another terminal, could help.
I found this one-liner solution on SU to be a lot more straightforward than the accepted answer. Since it uses an environmental variable for the local IP address, I think that it also satisfies the OP's request to not know it in advance.
based on that, here's a bash function to "DownLoad" a file (i.e. push from SSH session to a set location on the local machine)
function dl(){
scp "$1" ${CLIENT_IP%% *}:/home/<USER>/Downloads
}
Now I can just call dl somefile.txt
while SSH'd into the remote and somefile.txt
appears in my local Downloads folder.
extras:
- I use rsa keys (ssh-copy-id) to get around password prompt
- I found this trick to prevent the local bashrc from being sourced on the scp call
Note: this requires SSH access to local machine from remote (is this often the case for anyone?)