This class implements the File Transfer Protocol. If you have used a command-line FTP program, and are familiar with the commands, you will be able to use this class easily. Some extra features are included to take advantage of Ruby's style and strengths.

Example

require 'net/ftp'

Example 1

ftp = Net::FTP.new('example.com')
ftp.login
files = ftp.chdir('pub/lang/ruby/contrib')
files = ftp.list('n*')
ftp.getbinaryfile('nif.rb-0.91.gz', 'nif.gz', 1024)
ftp.close

Example 2

Net::FTP.open('example.com') do |ftp|
  ftp.login
  files = ftp.chdir('pub/lang/ruby/contrib')
  files = ftp.list('n*')
  ftp.getbinaryfile('nif.rb-0.91.gz', 'nif.gz', 1024)
end

Major Methods

The following are the methods most likely to be useful to users:

Namespace
Methods
A
B
C
D
G
H
L
M
N
O
P
Q
R
S
V
Included Modules
Constants
CASE_DEPENDENT_PARSER = ->(value) { value }
 
CASE_INDEPENDENT_PARSER = ->(value) { value.downcase }
 
DECIMAL_PARSER = ->(value) { value.to_i }
 
OCTAL_PARSER = ->(value) { value.to_i(8) }
 
TIME_PARSER = ->(value, local = false) { unless /\A(?<year>\d{4})(?<month>\d{2})(?<day>\d{2}) (?<hour>\d{2})(?<min>\d{2})(?<sec>\d{2}) (\.(?<fractions>\d+))?/x =~ value raise FTPProtoError, "invalid time-val: #{value}" end usec = fractions.to_i * 10 ** (6 - fractions.to_s.size) Time.send(local ? :local : :utc, year, month, day, hour, min, sec, usec) }
 
FACT_PARSERS = Hash.new(CASE_DEPENDENT_PARSER)
 
Attributes
[R] binary

When true, transfers are performed in binary mode. Default: true.

[RW] debug_mode

When true, all traffic to and from the server is written to +$stdout+. Default: false.

[R] last_response

The server's last response.

[R] last_response_code

The server's last response code.

[R] lastresp

The server's last response code.

[RW] open_timeout

Number of seconds to wait for the connection to open. Any number may be used, including Floats for fractional seconds. If the FTP object cannot open a connection in this many seconds, it raises a Net::OpenTimeout exception. The default value is nil.

[RW] passive

When true, the connection is in passive mode. Default: true.

[R] read_timeout

Number of seconds to wait for one block to be read (via one read(2) call). Any number may be used, including Floats for fractional seconds. If the FTP object cannot read data in this many seconds, it raises a Timeout::Error exception. The default value is 60 seconds.

[RW] resume

Sets or retrieves the resume status, which decides whether incomplete transfers are resumed or restarted. Default: false.

[R] welcome

The server's welcome message.

Class Public methods
default_passive()

When true, connections are in passive mode per default. Default: true.

# File lib/net/ftp.rb, line 136
def self.default_passive
  @@default_passive
end
default_passive=(value)

When true, connections are in passive mode per default. Default: true.

# File lib/net/ftp.rb, line 130
def self.default_passive=(value)
  @@default_passive = value
end
new(host = nil, user = nil, passwd = nil, acct = nil)

Creates and returns a new FTP object. If a host is given, a connection is made. Additionally, if the user is given, the given user name, password, and (optionally) account are used to log in. See login.

# File lib/net/ftp.rb, line 164
def initialize(host = nil, user = nil, passwd = nil, acct = nil)
  super()
  @binary = true
  @passive = @@default_passive
  @debug_mode = false
  @resume = false
  @sock = NullSocket.new
  @logged_in = false
  @open_timeout = nil
  @read_timeout = 60
  if host
    connect(host)
    if user
      login(user, passwd, acct)
    end
  end
end
open(host, user = nil, passwd = nil, acct = nil)

A synonym for FTP.new, but with a mandatory host parameter.

If a block is given, it is passed the FTP object, which will be closed when the block finishes, or when an exception is raised.

# File lib/net/ftp.rb, line 146
def FTP.open(host, user = nil, passwd = nil, acct = nil)
  if block_given?
    ftp = new(host, user, passwd, acct)
    begin
      yield ftp
    ensure
      ftp.close
    end
  else
    new(host, user, passwd, acct)
  end
end
Instance Public methods
abort()

Aborts the previous command (ABOR command).

# File lib/net/ftp.rb, line 1097
def abort
  line = "ABOR" + CRLF
  print "put: ABOR\n" if @debug_mode
  @sock.send(line, Socket::MSG_OOB)
  resp = getmultiline
  unless ["426", "226", "225"].include?(resp[0, 3])
    raise FTPProtoError, resp
  end
  return resp
end
acct(account)

Sends the ACCT command.

This is a less common FTP command, to send account information if the destination host requires it.

# File lib/net/ftp.rb, line 750
def acct(account)
  cmd = "ACCT " + account
  voidcmd(cmd)
end
binary=(newmode)

A setter to toggle transfers in binary mode. newmode is either true or false

# File lib/net/ftp.rb, line 184
def binary=(newmode)
  if newmode != @binary
    @binary = newmode
    send_type_command if @logged_in
  end
end
chdir(dirname)

Changes the (remote) directory.

# File lib/net/ftp.rb, line 1018
def chdir(dirname)
  if dirname == ".."
    begin
      voidcmd("CDUP")
      return
    rescue FTPPermError => e
      if e.message[0, 3] != "500"
        raise e
      end
    end
  end
  cmd = "CWD #{dirname}"
  voidcmd(cmd)
end
close()

Closes the connection. Further operations are impossible until you open a new connection with connect.

# File lib/net/ftp.rb, line 1170
def close
  if @sock and not @sock.closed?
    begin
      @sock.shutdown(Socket::SHUT_WR) rescue nil
      orig, self.read_timeout = self.read_timeout, 3
      @sock.read rescue nil
    ensure
      @sock.close
      self.read_timeout = orig
    end
  end
end
closed?()

Returns true iff the connection is closed.

# File lib/net/ftp.rb, line 1186
def closed?
  @sock == nil or @sock.closed?
end
connect(host, port = FTP_PORT)

Establishes an FTP connection to host, optionally overriding the default port. If the environment variable SOCKS_SERVER is set, sets up the connection through a SOCKS proxy. Raises an exception (typically Errno::ECONNREFUSED) if the connection cannot be established.

# File lib/net/ftp.rb, line 258
def connect(host, port = FTP_PORT)
  if @debug_mode
    print "connect: ", host, ", ", port, "\n"
  end
  synchronize do
    @sock = open_socket(host, port)
    voidresp
  end
end
delete(filename)

Deletes a file on the server.

# File lib/net/ftp.rb, line 1004
def delete(filename)
  resp = sendcmd("DELE #{filename}")
  if resp.start_with?("250")
    return
  elsif resp.start_with?("5")
    raise FTPPermError, resp
  else
    raise FTPReplyError, resp
  end
end
dir(*args)
Alias for: list
get(remotefile, localfile = File.basename(remotefile), blocksize = DEFAULT_BLOCKSIZE)

Retrieves remotefile in whatever mode the session is set (text or binary). See gettextfile and getbinaryfile.

# File lib/net/ftp.rb, line 679
def get(remotefile, localfile = File.basename(remotefile),
        blocksize = DEFAULT_BLOCKSIZE, &block) # :yield: data
  if @binary
    getbinaryfile(remotefile, localfile, blocksize, &block)
  else
    gettextfile(remotefile, localfile, &block)
  end
end
getbinaryfile(remotefile, localfile = File.basename(remotefile), blocksize = DEFAULT_BLOCKSIZE)

Retrieves remotefile in binary mode, storing the result in localfile. If localfile is nil, returns retrieved data. If a block is supplied, it is passed the retrieved data in blocksize chunks.

# File lib/net/ftp.rb, line 618
def getbinaryfile(remotefile, localfile = File.basename(remotefile),
                  blocksize = DEFAULT_BLOCKSIZE, &block) # :yield: data
  f = nil
  result = nil
  if localfile
    if @resume
      rest_offset = File.size?(localfile)
      f = open(localfile, "a")
    else
      rest_offset = nil
      f = open(localfile, "w")
    end
  elsif !block_given?
    result = String.new
  end
  begin
    f&.binmode
    retrbinary("RETR #{remotefile}", blocksize, rest_offset) do |data|
      f&.write(data)
      block&.(data)
      result&.concat(data)
    end
    return result
  ensure
    f&.close
  end
end
getdir()
Alias for: pwd
gettextfile(remotefile, localfile = File.basename(remotefile))

Retrieves remotefile in ASCII (text) mode, storing the result in localfile. If localfile is nil, returns retrieved data. If a block is supplied, it is passed the retrieved data one line at a time.

# File lib/net/ftp.rb, line 653
def gettextfile(remotefile, localfile = File.basename(remotefile),
                &block) # :yield: line
  f = nil
  result = nil
  if localfile
    f = open(localfile, "w")
  elsif !block_given?
    result = String.new
  end
  begin
    retrlines("RETR #{remotefile}") do |line, newline|
      l = newline ? line + "\n" : line
      f&.print(l)
      block&.(line, newline)
      result&.concat(l)
    end
    return result
  ensure
    f&.close
  end
end
help(arg = nil)

Issues the HELP command.

# File lib/net/ftp.rb, line 1134
def help(arg = nil)
  cmd = "HELP"
  if arg
    cmd = cmd + " " + arg
  end
  sendcmd(cmd)
end
list(*args)

Returns an array of file information in the directory (the output is like `ls -l`). If a block is given, it iterates through the listing.

Also aliased as: ls, dir
# File lib/net/ftp.rb, line 774
def list(*args, &block) # :yield: line
  cmd = "LIST"
  args.each do |arg|
    cmd = "#{cmd} #{arg}"
  end
  lines = []
  retrlines(cmd) do |line|
    lines << line
  end
  if block
    lines.each(&block)
  end
  return lines
end
login(user = "anonymous", passwd = nil, acct = nil)

Logs in to the remote host. The session must have been previously connected. If user is the string “anonymous” and the password is nil, “anonymous@” is used as a password. If the acct parameter is not nil, an FTP ACCT command is sent following the successful login. Raises an exception on error (typically Net::FTPPermError).

# File lib/net/ftp.rb, line 469
def login(user = "anonymous", passwd = nil, acct = nil)
  if user == "anonymous" and passwd == nil
    passwd = "anonymous@"
  end

  resp = ""
  synchronize do
    resp = sendcmd('USER ' + user)
    if resp.start_with?("3")
      raise FTPReplyError, resp if passwd.nil?
      resp = sendcmd('PASS ' + passwd)
    end
    if resp.start_with?("3")
      raise FTPReplyError, resp if acct.nil?
      resp = sendcmd('ACCT ' + acct)
    end
  end
  if !resp.start_with?("2")
    raise FTPReplyError, resp
  end
  @welcome = resp
  send_type_command
  @logged_in = true
end
ls(*args)
Alias for: list
mdtm(filename)

Returns the raw last modification time of the (remote) file in the format “YYYYMMDDhhmmss” (MDTM command).

Use mtime if you want a parsed Time instance.

# File lib/net/ftp.rb, line 1124
def mdtm(filename)
  resp = sendcmd("MDTM #{filename}")
  if resp.start_with?("213")
    return get_body(resp)
  end
end
mkdir(dirname)

Creates a remote directory.

# File lib/net/ftp.rb, line 1062
def mkdir(dirname)
  resp = sendcmd("MKD #{dirname}")
  return parse257(resp)
end
mlsd(pathname = nil)

Returns an array of the entries of the directory specified by pathname. Each entry has the facts (e.g., size, last modification time, etc.) and the pathname. If a block is given, it iterates through the listing. If pathname is omitted, the current directory is assumed.

# File lib/net/ftp.rb, line 978
def mlsd(pathname = nil, &block) # :yield: entry
  cmd = pathname ? "MLSD #{pathname}" : "MLSD"
  entries = []
  retrlines(cmd) do |line|
    entries << parse_mlsx_entry(line)
  end
  if block
    entries.each(&block)
  end
  return entries
end
mlst(pathname = nil)

Returns data (e.g., size, last modification time, entry type, etc.) about the file or directory specified by pathname. If pathname is omitted, the current directory is assumed.

# File lib/net/ftp.rb, line 956
def mlst(pathname = nil)
  cmd = pathname ? "MLST #{pathname}" : "MLST"
  resp = sendcmd(cmd)
  if !resp.start_with?("250")
    raise FTPReplyError, resp
  end
  line = resp.lines[1]
  unless line
    raise FTPProtoError, resp
  end
  entry = line.sub(/\A(250-| *)/, "")
  return parse_mlsx_entry(entry)
end
mtime(filename, local = false)

Returns the last modification time of the (remote) file. If local is true, it is returned as a local time, otherwise it's a UTC time.

# File lib/net/ftp.rb, line 1055
def mtime(filename, local = false)
  return TIME_PARSER.(mdtm(filename), local)
end
nlst(dir = nil)

Returns an array of filenames in the remote directory.

# File lib/net/ftp.rb, line 758
def nlst(dir = nil)
  cmd = "NLST"
  if dir
    cmd = "#{cmd} #{dir}"
  end
  files = []
  retrlines(cmd) do |line|
    files.push(line)
  end
  return files
end
noop()

Issues a NOOP command.

Does nothing except return a response.

# File lib/net/ftp.rb, line 1154
def noop
  voidcmd("NOOP")
end
put(localfile, remotefile = File.basename(localfile), blocksize = DEFAULT_BLOCKSIZE, &block)

Transfers localfile to the server in whatever mode the session is set (text or binary). See puttextfile and putbinaryfile.

# File lib/net/ftp.rb, line 735
def put(localfile, remotefile = File.basename(localfile),
        blocksize = DEFAULT_BLOCKSIZE, &block)
  if @binary
    putbinaryfile(localfile, remotefile, blocksize, &block)
  else
    puttextfile(localfile, remotefile, &block)
  end
end
putbinaryfile(localfile, remotefile = File.basename(localfile), blocksize = DEFAULT_BLOCKSIZE)

Transfers localfile to the server in binary mode, storing the result in remotefile. If a block is supplied, calls it, passing in the transmitted data in blocksize chunks.

# File lib/net/ftp.rb, line 693
def putbinaryfile(localfile, remotefile = File.basename(localfile),
                  blocksize = DEFAULT_BLOCKSIZE, &block) # :yield: data
  if @resume
    begin
      rest_offset = size(remotefile)
    rescue Net::FTPPermError
      rest_offset = nil
    end
  else
    rest_offset = nil
  end
  f = open(localfile)
  begin
    f.binmode
    if rest_offset
      storbinary("APPE #{remotefile}", f, blocksize, rest_offset, &block)
    else
      storbinary("STOR #{remotefile}", f, blocksize, rest_offset, &block)
    end
  ensure
    f.close
  end
end
puttextfile(localfile, remotefile = File.basename(localfile))

Transfers localfile to the server in ASCII (text) mode, storing the result in remotefile. If callback or an associated block is supplied, calls it, passing in the transmitted data one line at a time.

# File lib/net/ftp.rb, line 722
def puttextfile(localfile, remotefile = File.basename(localfile), &block) # :yield: line
  f = open(localfile)
  begin
    storlines("STOR #{remotefile}", f, &block)
  ensure
    f.close
  end
end
pwd()

Returns the current remote directory.

Also aliased as: getdir
# File lib/net/ftp.rb, line 1077
def pwd
  resp = sendcmd("PWD")
  return parse257(resp)
end
quit()

Exits the FTP session.

# File lib/net/ftp.rb, line 1145
def quit
  voidcmd("QUIT")
end
read_timeout=(sec)

Setter for the #read_timeout attribute.

# File lib/net/ftp.rb, line 113
def read_timeout=(sec)
  @sock.read_timeout = sec
  @read_timeout = sec
end
rename(fromname, toname)

Renames a file on the server.

# File lib/net/ftp.rb, line 993
def rename(fromname, toname)
  resp = sendcmd("RNFR #{fromname}")
  if !resp.start_with?("3")
    raise FTPReplyError, resp
  end
  voidcmd("RNTO #{toname}")
end
retrbinary(cmd, blocksize, rest_offset = nil)

Puts the connection into binary (image) mode, issues the given command, and fetches the data returned, passing it to the associated block in chunks of blocksize characters. Note that cmd is a server command (such as “RETR myfile”).

# File lib/net/ftp.rb, line 500
def retrbinary(cmd, blocksize, rest_offset = nil) # :yield: data
  synchronize do
    with_binary(true) do
      begin
        conn = transfercmd(cmd, rest_offset)
        loop do
          data = conn.read(blocksize)
          break if data == nil
          yield(data)
        end
        conn.shutdown(Socket::SHUT_WR)
        conn.read_timeout = 1
        conn.read
      ensure
        conn.close if conn
      end
      voidresp
    end
  end
end
retrlines(cmd)

Puts the connection into ASCII (text) mode, issues the given command, and passes the resulting data, one line at a time, to the associated block. If no block is given, prints the lines. Note that cmd is a server command (such as “RETR myfile”).

# File lib/net/ftp.rb, line 527
def retrlines(cmd) # :yield: line
  synchronize do
    with_binary(false) do
      begin
        conn = transfercmd(cmd)
        loop do
          line = conn.gets
          break if line == nil
          yield(line.sub(/\r?\n\z/, ""), !line.match(/\n\z/).nil?)
        end
        conn.shutdown(Socket::SHUT_WR)
        conn.read_timeout = 1
        conn.read
      ensure
        conn.close if conn
      end
      voidresp
    end
  end
end
rmdir(dirname)

Removes a remote directory.

# File lib/net/ftp.rb, line 1070
def rmdir(dirname)
  voidcmd("RMD #{dirname}")
end
sendcmd(cmd)

Sends a command and returns the response.

# File lib/net/ftp.rb, line 367
def sendcmd(cmd)
  synchronize do
    putline(cmd)
    return getresp
  end
end
set_socket(sock, get_greeting = true)

Set the socket used to connect to the FTP server.

May raise FTPReplyError if get_greeting is false.

# File lib/net/ftp.rb, line 272
def set_socket(sock, get_greeting = true)
  synchronize do
    @sock = sock
    if get_greeting
      voidresp
    end
  end
end
site(arg)

Issues a SITE command.

# File lib/net/ftp.rb, line 1161
def site(arg)
  cmd = "SITE " + arg
  voidcmd(cmd)
end
size(filename)

Returns the size of the given (remote) filename.

# File lib/net/ftp.rb, line 1041
def size(filename)
  with_binary(true) do
    resp = sendcmd("SIZE #{filename}")
    if !resp.start_with?("213")
      raise FTPReplyError, resp
    end
    return get_body(resp).to_i
  end
end
status()

Returns the status (STAT command).

# File lib/net/ftp.rb, line 1111
def status
  line = "STAT" + CRLF
  print "put: STAT\n" if @debug_mode
  @sock.send(line, Socket::MSG_OOB)
  return getresp
end
storbinary(cmd, file, blocksize, rest_offset = nil)

Puts the connection into binary (image) mode, issues the given server-side command (such as “STOR myfile”), and sends the contents of the file named file to the server. If the optional block is given, it also passes it the data, in chunks of blocksize characters.

# File lib/net/ftp.rb, line 554
def storbinary(cmd, file, blocksize, rest_offset = nil) # :yield: data
  if rest_offset
    file.seek(rest_offset, IO::SEEK_SET)
  end
  synchronize do
    with_binary(true) do
      conn = transfercmd(cmd)
      loop do
        buf = file.read(blocksize)
        break if buf == nil
        conn.write(buf)
        yield(buf) if block_given?
      end
      conn.close
      voidresp
    end
  end
rescue Errno::EPIPE
  # EPIPE, in this case, means that the data connection was unexpectedly
  # terminated.  Rather than just raising EPIPE to the caller, check the
  # response on the control connection.  If getresp doesn't raise a more
  # appropriate exception, re-raise the original exception.
  getresp
  raise
end
storlines(cmd, file)

Puts the connection into ASCII (text) mode, issues the given server-side command (such as “STOR myfile”), and sends the contents of the file named file to the server, one line at a time. If the optional block is given, it also passes it the lines.

# File lib/net/ftp.rb, line 586
def storlines(cmd, file) # :yield: line
  synchronize do
    with_binary(false) do
      conn = transfercmd(cmd)
      loop do
        buf = file.gets
        break if buf == nil
        if buf[-2, 2] != CRLF
          buf = buf.chomp + CRLF
        end
        conn.write(buf)
        yield(buf) if block_given?
      end
      conn.close
      voidresp
    end
  end
rescue Errno::EPIPE
  # EPIPE, in this case, means that the data connection was unexpectedly
  # terminated.  Rather than just raising EPIPE to the caller, check the
  # response on the control connection.  If getresp doesn't raise a more
  # appropriate exception, re-raise the original exception.
  getresp
  raise
end
system()

Returns system information.

# File lib/net/ftp.rb, line 1086
def system
  resp = sendcmd("SYST")
  if !resp.start_with?("215")
    raise FTPReplyError, resp
  end
  return get_body(resp)
end
voidcmd(cmd)

Sends a command and expect a response beginning with '2'.

# File lib/net/ftp.rb, line 377
def voidcmd(cmd)
  synchronize do
    putline(cmd)
    voidresp
  end
end