I’ve written a crude module for retrieving files from a remote server using rsync, since I didn’t see any existing tools already. This could be useful anywhere one needs to efficiently move files across filesystem or network boundaries, and could even be used for better control and monitoring of deployments. Does it sound like something I should package into a library?

The inner logic takes advantage of the --info=progress2 reporting mode for rsync, reading status lines to monitor progress:

port = Port.open(
  {:spawn_executable, System.find_executable("rsync")},
  [args: ["-a", "--info=progress2"] ++ remote_urls ++ [local_path],
    :binary, :exit_status, :hide, :use_stdio, :stderr_to_stdout]
)

receive do
  {^port, {:data, data}} ->
    ....

  {^port, {:exit_status, status}} ->
    ....
end