github.com/jramnani/go-ftp

Status: Experimental

TODO:

• Log in. -- Done
• Download a file. -- Done
• Upload a file to an existing directory. -- Done
• List contents of remote directory.
• Create a new directory.
• Delete a a directory or a file.

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FTP Protocol Command Summary

• To Download a file:

  • Log in USER username PASS password

  • Set the TYPE TYPE I (binary) for binary files or TYPE A (ascii) for text files

    Sample Response: 200 Type set to A or I

  • Set Passive transfer mode PASV Computing the destination port from the actual respone (127,0,0,1,201,208) The first four octets are the IP address while the last two octets comprise the port that will be used for the data connection. To find the actual port multiply the fifth octet by 256 and then add the sixth octet to the total

    Sample Response: 227 Entering Passive Mode (127,0,0,1,201,208)
    

  • Retrieve the file RETR [file] After you call RETR the data port will open and be available to download the file. RETR doesn't return immediately, but waits until you open a connection to the data port and download the file.

    Sample Response: 150 opening connection
    

  • Open connection to data port Read data bytes to a file Sample Response: 226 Transfer complete

  • Close data port

  • Close the connection (optional, if you want to download multiple files in one session) QUIT

Sample Protocol Session (control session only):

$ telnet localhost 21 220 ProFTPD 1.3.2c Server (ProFTPD Test Server) [127.0.0.1] USER 500 USER: command requires a parameter USER anonymous 331 Anonymous login ok, send your complete email address as your password PASS foo 230 Anonymous access granted, restrictions apply

TYPE I 200 Type set to I PASV 227 Entering Passive Mode (127,0,0,1,201,208).

RETR test_file.txt 150 Opening BINARY mode data connection for test_file.txt (12 bytes) 226 Transfer complete QUIT 221 Goodbye.