Saturday, November 13, 2010

Linux / UNIX FTP Commands Tutorial

SkyHi @ Saturday, November 13, 2010
I switched from MS-Windows to Mac computer running OS X UNIX systems. I need to transfer and download file using ftp for my personal website. Can you provide me a list of FTP commands that may be sent to an FTP server, to upload and download files using UNIX / Linux ftp command line client?

File Transfer Protocol (FTP) is a network protocol used to copy a file from one computer to another over the Internet or LAN. FTP follows a client-server architecture which utilizes separate control and data connections between the ftp client and server. The default port for ftp is 21.
WARNING! These examples uses outdated insecure ftp protocol / client and if executed you are open to various attacks including password snooping. I strongly recommend that you use sftp, the secure version of FTP. Just type sftp instead of ftp and all of the following commands should work with sftp client too.

ftp: Internet File Transfer Program

Use the following syntax to connect to transfer files to and from a remote network ftp site:
ftp ftp.example.com
ftp 1.2.3.4
ftp user@ftp.example.com
You must know ftp username and password for user-based password authentication or with anonymous user access use ftp as both username and password. In this example, you are connecting to ftp.freebsd.org with anonymous user access (open the terminal and type the following command):
$ ftp ftp.freebsd.org
Sample session:
Trying 87.51.34.132...
Connected to ftp.freebsd.org.
220 ftp.beastie.tdk.net FTP server (Version 6.00LS) ready.
Name (ftp.freebsd.org:vivek): ftp
331 Guest login ok, send your email address as password.
Password:
230 Guest login ok, access restrictions apply.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp>
When you enter your own loginname and password for the ftp.example.com server, it returns the prompt
ftp>
You need to type all commands in front of the ftp> prompt.

Task: List Current File

Type the ls command at ftp> prompt:
ftp> ls
Sample outputs:
229 Entering Extended Passive Mode (|||60692|)
150 Opening ASCII mode data connection for '/bin/ls'.
total 10
drwxrwxr-x  2 0     5      512 Jul 19  2007 .snap
drwx------  2 0     0     2048 Jul 19  2007 lost+found
drwxr-xr-x  3 1006  1006   512 Sep 21  2009 pub
drwxr-xr-x  3 1006  1006   512 Jun  5  2007 sup
drwxr-xr-x  4 1006  0      512 Sep 18  2009 www
226 Transfer complete.
ftp>
The above will list the names of the files in the current remote directory (the last name is file or dir name).

Task: Change Directory

To change directory on the remote machine use cd command:
ftp> cd dirName
To change to pub directory, enter:
ftp> cd pub
Sample outputs:
250 CWD command successful.

Task: Download / Copy file

To copy one file at a time from the remote ftp server to the local system use get command:
get fileName
get fileName newFileName
In this example, download file resume.pdf in the current remote directory to (or on top of) a file with the same name, resume.pdf, in your current local directory:
ftp> get resume.pdf
Sample outputs:
local: resume.pdf remote: resume.pdf
229 Entering Extended Passive Mode (|||55093|)
150 Opening BINARY mode data connection for 'resume.pdf' (53077 bytes).
100% |*********************************************************************| 53077       12.58 KiB/s    00:00 ETA
226 Transfer complete.
53077 bytes received in 00:04 (12.57 KiB/s)
In this example, copies file data.tar.gz in the current remote directory to (or on top of) a file named backup.tar.gz in your current local directory:
ftp> get data.tar.gz backup.tar.gz

Change Local Directory

To change directory on your local system, enter:
ftp> lcd /path/to/new/dir
ftp> lcd /tmp

Sample outputs:
Local directory now: /tmp
Print local directory:
ftp> lpwd
Sample outputs:
/tmp
The lpwd command prints current download directory for local systems. However, to find out the pathname of the current directory on the remote ftp server, enter:
ftp> pwd
Sample outputs:
Remote directory: /pub/FreeBSD

Task: Download Multiple Files

You need to use mget command as follows to copy multiple files from the remote ftp server to the local system. You may be prompted for a yes/no (Y/N) answer before transferring each file (you can disable prompt by passing the -i option to ftp client). To download all files, enter:
ftp> mget *
To download all perl files (ending with .pl extension), enter:
ftp> mget *.pl

Task: Turn On / Off Interactive Prompting

The ftp command prompt sets interactive prompting; "on" which enables prompting so that you can verify of each step of the multiple commands, "off" allows the commands to act unimpeded:
ftp> prompt on
ftp> mput *.php
ftp> prompt off
ftp> mget *.py

Task: Delete File

To delete a file in the current remote directory use delete command:
ftp> delete fileName
ftp> delete output.jpg

Task: Upload One File

To copy one file at a time from the local systems to the remote ftp server, enter:
ftp> put fileName
In this example, upload logo.jpg, enter:
ftp> put logo.jpg

Task: Upload Multiple Files

To copy multiple files from the local system to the remote ftp server use mput command. Again, you may be prompted for a yes/no (y/n) answer before transferring each file. In this example, upload all files from the current system:
ftp> mput *
ftp> mput *.pl

Task: Create a Directory

To make a new directory, enter:
ftp> mkdir dirName
ftp> mkdir scripts
ftp> cd scripts
ftp> pwd

Task: Delete a Directory

To remove or delete a directory, enter:
ftp> rmdir dirName
ftp> rmdir images
ftp> ls

Task: Set The Mode Of File Transfer

To set the mode of file transfer to ASCII, enter:
ftp> ascii
Please note that ascii is the default and good for text files. To set the mode of file transfer to binary, enter:
ftp> binary
The binary mode is recommended for almost all sort of files including images, zip files and much more. The binary mode provides less chance of a transmission error.

Task: Connect To Another FTP Server

To open a connection with another ftp server, enter:
ftp> open ftp.nixcraft.net.in
The above command opens a new FTP connection with ftp.nixcraft.net.in. You must provide a username and password for a ftp.nixcraft.net.in account. However, a username and password can be skipped for an anonymous FTP connection.

Task: Exit the FTP Session

Type quit or bye, enter:
ftp> quit
OR
ftp> bye
Sample outputs:
221 Goodbye.

How Do I Find Out More Information About The FTP Commands?

Type ? or help to get more information about the FTP commands:
ftp> ?
ftp> help

Sample outputs:
Commands may be abbreviated.  Commands are:

!  delete  idle  mode  pmlsd  reset  system
$  dir  image  modtime  preserve restart  tenex
account  disconnect lcd  more  progress rhelp  throttle
append  edit  less  mput  prompt  rmdir  trace
ascii  epsv4  lpage  mreget  proxy  rstatus  type
bell  exit  lpwd  msend  put  runique  umask
binary  features ls  newer  pwd  send  unset
bye  fget  macdef  nlist  quit  sendport usage
case  form  mdelete  nmap  quote  set  user
cd  ftp  mdir  ntrans  rate  site  verbose
cdup  gate  mget  open  rcvbuf  size  xferbuf
chmod  get  mkdir  page  recv  sndbuf  ?
close  glob  mls  passive  reget  status
cr  hash  mlsd  pdir  remopts  struct
debug  help  mlst  pls  rename  sunique
To get a short description about each command, enter:
ftp> help commandName
ftp> help chmod

Sample outputs:
chmod       change file permissions of remote file
ftp> help ls
Sample outputs:
ls          list contents of remote path

FTP Through A Browser

If you do not want to type the commands, than use a browser such as Safari, Firefox and type the following:
ftp://ftpUserName@ftp.nixcraft.net.in
ftp://ftp.freebsd.org/
ftp://ftp@ftp.freebsd.org/
ftp://userName:Password@ftp.nixcraft.net.in/
ftp://ftp:ftp@ftp.freebsd.org/

Sample outputs:

UNIX / Linux FireFOX - FTP through a browser
Fig.01: FTP through a browser

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