====== How to transfer files between Linux/Mac computers using SFTP from the Command Line ======
This information is provided for the [[https://www.ubuntu.com/|Ubuntu]]/Debian editions of Linux used in the CS Department. Other Linux versions may vary.




===== What Is SFTP? =====

In Linux, you can use the Secure File Transfer Protocol (SSH File Transfer Protocol) (**[[cs101:sftp|SFTP]]**) from the command line (**[[cs101:cli|CLI]]**) (the sftp command) to securely copy files and directories between remote hosts.

In most cases, SFTP is preferable to **[[cs101:ftp|FTP]]** because of its underlying security features and ability to piggy-back on an SSH connection. FTP is an insecure protocol that should only be used in limited cases or on trusted networks. FTP is NOT available on CS Department computers.




==== How to Connect with SFTP ====
You can establish a SFTP connection by issuing the following command:

  sftp [options] remote_username@remote_host

You will connect the the remote system and your prompt will change to an SFTP prompt.

  * Name of the account on the host computer (remote_username)
  * Hostname (i.e. [[cs101:fqdn|FQDN]]) of the computer on which the source file resides (remote_host)

Options can include things like [-oPort=custom_port] if not connecting to the standard SSH port 22.





==== Navigating with SFTP ====
Once connected to the remote host, you can navigate around the remote file system with commands similar to the Unix/Linux Shell.

  * pwd: show remote working directory.
  * ls:  view contents of the current remote directory. 
  * cd:  change remote directory.
You can direct commands towards the local file system by preceding them with an “l” for local.
  * lpwd: show local working directory.
  * lls:  view contents of the current local directory. 
  * lcd:  change local directory.




==== Transferring Remote Files to the Local System ====
Transferring files from the remote system is accomplished by using the appropriately named “get” command:

To download a file from the remote host.
  get remote_filename
  
To download a file from the remote host and rename.
  get remote_filename new_local_filename

To download a directory and it's contents.
  get -r remote_directory

To preserve full file permissions and access times during the copy, use the -p flag.
  get -p remote_filename





==== Transferring Local Files to the Remote System ====

Transferring files to the remote system is accomplished by using the appropriately named “put” command:

To upload a file to the remote host. 
  put local_filename

To upload an entire local directory to the remote host.
  put -r local_directory




==== Quitting SFTP ====
To quit a SFTP session use the exit command
  exit
===== Getting Help in SFTP =====
SFTP has a help command. This gives you access to a summary of the SFTP help. You can call it by typing either of these in the prompt:

  help

  ?

This will display a list of the available commands:

You can find more information on Ubuntu SFTP in the [[http://manpages.ubuntu.com/manpages/focal/en/man1/sftp.1.html|Ubuntu man pages]]