A Julia FTP client using LibCURL supporting FTP and FTP over SSL.

Depending on the settings of the FTP server you are connecting to you may need to deal with various security settings.

• FTP with no Transport Layer Security (FTP). Typically uses port 21/TCP.

  julia> ftp = FTP(hostname="example.com", username="user", password="1234")
  URL:       ftp://user:*****@example.com/
  Transfer:  passive mode
  Security:  none
  
  julia> ftp = FTP("ftp://user:[email protected]")
  URL:       ftp://user:*****@example.com/
  Transfer:  passive mode
  Security:  none

• FTP with implicit security (FTPS). Typically uses port 990/TCP.

  julia> ftp = FTP(hostname="example.com", username="user", password="1234", ssl=true, implicit=true)
  URL:       ftps://user:*****@example.com/
  Transfer:  passive mode
  Security:  implicit
  
  julia> ftp = FTP("ftps://user:[email protected]")
  URL:       ftps://user:*****@example.com/
  Transfer:  passive mode
  Security:  implicit

• FTP with explicit security (FTPES). Typically uses port 21/TCP.

  julia> ftp = FTP(hostname="example.com", username="user", password="1234", ssl=true, implicit=false)
  URL:       ftpes://user:*****@example.com/
  Transfer:  passive mode
  Security:  explicit
  
  julia> ftp = FTP("ftpes://user:[email protected]")
  URL:       ftpes://user:*****@example.com/
  Transfer:  passive mode
  Security:  explicit

Once you've created your FTP instance you can use many of the filesystem functions that Julia provides. A quick example showing some of the functions available:

julia> cd(ftp, "Documents/School")

julia> pwd(ftp)
"/Documents/School"

julia> readdir(ftp)
1-element Array{String,1}:
 "Assignment1.txt"
 "Assignment2.txt"

julia> io = download(ftp, "Assignment1.txt");  # Download as IO stream

julia> download(ftp, "Assignment2.txt", "./A2/Assignment2.txt");  # Save file to a specified path

julia> upload(ftp, "Assignment3.txt", ".")  # Upload local file "Assignment3.txt" to FTP server home directory

julia> open("Assignment3.txt") do fp
           upload(ftp, fp, "Assignment3-copy.txt")  # Upload IO content as file "Assignment3-copy.txt" on FTP server
       end

julia> mv(ftp, "Assignment3-copy.txt", "Assignment3-dup.txt")

julia> rm(ftp, "Assignment3-dup.txt")

julia> mkdir(ftp, "tmp")

julia> rmdir(ftp, "tmp")

julia> close(ftp)

If you want to upload a file but retry on failures you can do the following:

julia> ftp_retry = retry(delays=fill(5.0, 3)) do
           upload(ftp, "Assignment3.txt", ".")
       end

julia> ftp_retry()

Try downloading file in both binary and ASCII mode to see if one of the files is usable.

Travis CI currently [does not reliably support FTP connections on sudo-enabled Linux]https://blog.travis-ci.com/2018-07-23-the-tale-of-ftp-at-travis-ci). This will usually manifest itself as a Connection Timeout error. Disable sudo for a workaround.