Often I face this situation: I sshed into a remote server and ran some programs, and I want to copy their output files back to my local machine. What I do is remember the file path on remote machine, exit the connection, then scp user@remote:filepath .
Obviously this is not optimal. What I’m looking for is a way to let me scp file back to local machine without exiting the connection. I did some searching, almost all results are telling me how to do scp from my local machine, which I already know.
Is this possible? Better still, is it possible without needing to know the IP address of my local machine?
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Answer
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 user@example.com 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 user@127.0.0.1: user@127.0.0.1'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.