Baudet et Roire

I work with many remote servers and eventually I need to copy a file (or a bunch of them) to a directory that requires administrative privileges. My normal user does not have permissions for that, but I can get it via sudo.

Copying files to other servers is simple and I usually use rsync for that. After copying the files to a temporary location, I can use ssh to move files around.

If the remote server is set up to not ask for passwords when using sudo, this task can be done easily:

$ scp afile
$ ssh sudo mv -v /tmp/afile /etc/default/
renamed '/tmp/afile' -> '/etc/default/afile'

The scp command copies a file to a temporary directory on the remote server and then we execute sudo mv -v /tmp/afile /etc/default/ via ssh on the server to move the file to the final destination.

Note: I used scp in this example as it is simpler to type, but scp was deprecated. I use rsync instead.

I really like the -v flag for mv in this command, it serves as a confirmation that the file was indeed copied. -v is short for --verbose and, when used, mv tells you what file is being moved.

But this approach requires typing two commands, while we could use only one rsync command:

$ rsync -avzP --rsync-path="sudo rsync" afile
sending incremental file list
              3 100%    0.00kB/s    0:00:00 (xfr#1, to-chk=0/1)
sent 107 bytes  received 35 bytes  31.56 bytes/sec
total size is 3  speedup is 0.02

The magic words here are --rsync-path="sudo rsync". This flag specifies the path for the rsync executable on the remote machine. By using sudo rsync remotely, we can access the directory we want!

Of course, this approach also requires the remote user to be able to sudo without typing the password.

The other command line flags are:

  • -a (short for --archive): does quite a lot, but in summary is to be recursive and preserve almost all file attributes.
  • -v (short for --verbose): to see what is going on with more details.
  • -z (short for --compress): to compress the data when transferring files.
  • -P (short for --partial --progress): to show transfer progress and keep partial files in case of connection loss.


--rsync-path="sudo rsync" is the magical flag to be sudo on a remote machine, when the server is configured with passwordless sudo.