Protocol
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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.
require 'net/ftp'
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
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
The following are the methods most likely to be useful to users:
When true, all traffic to and from the server is written to +$stdout+.  Default: false.
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.
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.
Sets or retrieves the resume status, which decides whether incomplete transfers are resumed or restarted.  Default: false.
Number of seconds to wait for the TLS handshake. Any number may be used, including Floats for fractional seconds. If the FTP object cannot complete the TLS handshake in this many seconds, it raises a Net::OpenTimeout exception. The default value is nil. If ssl_handshake_timeout is nil, open_timeout is used instead.
When true, connections are in passive mode per default. Default: true.
 
               # File net/ftp.rb, line 152
def self.default_passive
  @@default_passive
end
             
            When true, connections are in passive mode per default. Default: true.
 
               # File net/ftp.rb, line 146
def self.default_passive=(value)
  @@default_passive = value
end
             
            Creates and returns a new FTP object. If a host is given, a connection is made.
options is an option hash, each key of which is a symbol.
The available options are:
Port number (default value is 21)
If options[:ssl] is true, then an attempt will be made to use SSL (now TLS) to connect to the server.  For this to work OpenSSL [OSSL] and the Ruby OpenSSL [RSSL] extensions need to be installed.  If options[:ssl] is a hash, it's passed to OpenSSL::SSL::SSLContext#set_params as parameters.
If true, TLS is used for data connections. Default: true when options[:ssl] is true.
Username for login.  If options[:username] is the string “anonymous” and the options[:password] is nil, “anonymous@” is used as a password.
Password for login.
Account information for ACCT.
When true, the connection is in passive mode. Default: true.
open_timeout
Number of seconds to wait for the connection to open. See Net::FTP#open_timeout for details.  Default: nil.
read_timeout
Number of seconds to wait for one block to be read. See Net::FTP#read_timeout for details.  Default: 60.
ssl_handshake_timeout
Number of seconds to wait for the TLS handshake. See Net::FTP#ssl_handshake_timeout for details.  Default: nil.
debug_mode
When true, all traffic to and from the server is written to +$stdout+.  Default: false.
 
               # File net/ftp.rb, line 212
def initialize(host = nil, user_or_options = {}, passwd = nil, acct = nil)
  super()
  begin
    options = user_or_options.to_hash
  rescue NoMethodError
    # for backward compatibility
    options = {}
    options[:username] = user_or_options
    options[:password] = passwd
    options[:account] = acct
  end
  @host = nil
  if options[:ssl]
    unless defined?(OpenSSL::SSL)
      raise "SSL extension not installed"
    end
    ssl_params = options[:ssl] == true ? {} : options[:ssl]
    @ssl_context = SSLContext.new
    @ssl_context.set_params(ssl_params)
    if defined?(VerifyCallbackProc)
      @ssl_context.verify_callback = VerifyCallbackProc
    end
    @ssl_context.session_cache_mode =
      OpenSSL::SSL::SSLContext::SESSION_CACHE_CLIENT |
      OpenSSL::SSL::SSLContext::SESSION_CACHE_NO_INTERNAL_STORE
    @ssl_context.session_new_cb = proc {|sock, sess| @ssl_session = sess }
    @ssl_session = nil
    if options[:private_data_connection].nil?
      @private_data_connection = true
    else
      @private_data_connection = options[:private_data_connection]
    end
  else
    @ssl_context = nil
    if options[:private_data_connection]
      raise ArgumentError,
        "private_data_connection can be set to true only when ssl is enabled"
    end
    @private_data_connection = false
  end
  @binary = true
  if options[:passive].nil?
    @passive = @@default_passive
  else
    @passive = options[:passive]
  end
  if options[:debug_mode].nil?
    @debug_mode = false
  else
    @debug_mode = options[:debug_mode]
  end
  @resume = false
  @bare_sock = @sock = NullSocket.new
  @logged_in = false
  @open_timeout = options[:open_timeout]
  @ssl_handshake_timeout = options[:ssl_handshake_timeout]
  @read_timeout = options[:read_timeout] || 60
  if host
    connect(host, options[:port] || FTP_PORT)
    if options[:username]
      login(options[:username], options[:password], options[:account])
    end
  end
end
             
            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 net/ftp.rb, line 162
def FTP.open(host, *args)
  if block_given?
    ftp = new(host, *args)
    begin
      yield ftp
    ensure
      ftp.close
    end
  else
    new(host, *args)
  end
end
             
            Aborts the previous command (ABOR command).
 
               # File net/ftp.rb, line 1231
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
             
            Sends the ACCT command.
This is a less common FTP command, to send account information if the destination host requires it.
 
               # File net/ftp.rb, line 884
def acct(account)
  cmd = "ACCT " + account
  voidcmd(cmd)
end
             
            A setter to toggle transfers in binary mode. newmode is either true or false
 
               # File net/ftp.rb, line 279
def binary=(newmode)
  if newmode != @binary
    @binary = newmode
    send_type_command if @logged_in
  end
end
             
            Changes the (remote) directory.
 
               # File net/ftp.rb, line 1152
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
             
            Closes the connection.  Further operations are impossible until you open a new connection with connect.
 
               # File net/ftp.rb, line 1345
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
             
            Returns true iff the connection is closed.
 
               # File net/ftp.rb, line 1361
def closed?
  @sock == nil or @sock.closed?
end
             
            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 net/ftp.rb, line 367
def connect(host, port = FTP_PORT)
  if @debug_mode
    print "connect: ", host, ", ", port, "\n"
  end
  synchronize do
    @host = host
    @bare_sock = open_socket(host, port)
    @sock = BufferedSocket.new(@bare_sock, read_timeout: @read_timeout)
    voidresp
    if @ssl_context
      begin
        voidcmd("AUTH TLS")
        ssl_sock = start_tls_session(@bare_sock)
        @sock = BufferedSSLSocket.new(ssl_sock, read_timeout: @read_timeout)
        if @private_data_connection
          voidcmd("PBSZ 0")
          voidcmd("PROT P")
        end
      rescue OpenSSL::SSL::SSLError, OpenTimeout
        @sock.close
        raise
      end
    end
  end
end
             
            Deletes a file on the server.
 
               # File net/ftp.rb, line 1138
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
             
            Issues a FEAT command
Returns an array of supported optional features
 
               # File net/ftp.rb, line 1311
def features
  resp = sendcmd("FEAT")
  if !resp.start_with?("211")
    raise FTPReplyError, resp
  end
  feats = []
  resp.split("\n").each do |line|
    next if !line.start_with?(' ') # skip status lines
    feats << line.strip
  end
  return feats
end
             
            Retrieves remotefile in whatever mode the session is set (text or binary).  See gettextfile and getbinaryfile.
 
               # File net/ftp.rb, line 813
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
             
            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 net/ftp.rb, line 752
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 = File.open(localfile, "a")
    else
      rest_offset = nil
      f = File.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
             
            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 net/ftp.rb, line 787
def gettextfile(remotefile, localfile = File.basename(remotefile),
                &block) # :yield: line
  f = nil
  result = nil
  if localfile
    f = File.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
             
            Issues the HELP command.
 
               # File net/ftp.rb, line 1274
def help(arg = nil)
  cmd = "HELP"
  if arg
    cmd = cmd + " " + arg
  end
  sendcmd(cmd)
end
             
            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.
 
               # File net/ftp.rb, line 908
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
             
            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 net/ftp.rb, line 599
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
             
            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 net/ftp.rb, line 1264
def mdtm(filename)
  resp = sendcmd("MDTM #{filename}")
  if resp.start_with?("213")
    return get_body(resp)
  end
end
             
            Creates a remote directory.
 
               # File net/ftp.rb, line 1196
def mkdir(dirname)
  resp = sendcmd("MKD #{dirname}")
  return parse257(resp)
end
             
            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 net/ftp.rb, line 1112
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
             
            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 net/ftp.rb, line 1090
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
             
            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 net/ftp.rb, line 1189
def mtime(filename, local = false)
  return TIME_PARSER.(mdtm(filename), local)
end
             
            Returns an array of filenames in the remote directory.
 
               # File net/ftp.rb, line 892
def nlst(dir = nil)
  cmd = "NLST"
  if dir
    cmd = "#{cmd} #{dir}"
  end
  files = []
  retrlines(cmd) do |line|
    files.push(line)
  end
  return files
end
             
            Issues a NOOP command.
Does nothing except return a response.
 
               # File net/ftp.rb, line 1294
def noop
  voidcmd("NOOP")
end
             
            Issues an OPTS command
name Should be the name of the option to set
params is any optional parameters to supply with the option
example: option('UTF8', 'ON') => 'OPTS UTF8 ON'
 
               # File net/ftp.rb, line 1334
def option(name, params = nil)
  cmd = "OPTS #{name}"
  cmd += " #{params}" if params
  voidcmd(cmd)
end
             
            Transfers localfile to the server in whatever mode the session is set (text or binary).  See puttextfile and putbinaryfile.
 
               # File net/ftp.rb, line 869
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
             
            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 net/ftp.rb, line 827
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 = File.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
             
            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 net/ftp.rb, line 856
def puttextfile(localfile, remotefile = File.basename(localfile), &block) # :yield: line
  f = File.open(localfile)
  begin
    storlines("STOR #{remotefile}", f, &block)
  ensure
    f.close
  end
end
             
            Returns the current remote directory.
 
               # File net/ftp.rb, line 1211
def pwd
  resp = sendcmd("PWD")
  return parse257(resp)
end
             
            Exits the FTP session.
 
               # File net/ftp.rb, line 1285
def quit
  voidcmd("QUIT")
end
             
            Setter for the read_timeout attribute.
 
               # File net/ftp.rb, line 129
def read_timeout=(sec)
  @sock.read_timeout = sec
  @read_timeout = sec
end
             
            Renames a file on the server.
 
               # File net/ftp.rb, line 1127
def rename(fromname, toname)
  resp = sendcmd("RNFR #{fromname}")
  if !resp.start_with?("3")
    raise FTPReplyError, resp
  end
  voidcmd("RNTO #{toname}")
end
             
            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 net/ftp.rb, line 630
def retrbinary(cmd, blocksize, rest_offset = nil) # :yield: data
  synchronize do
    with_binary(true) do
      begin
        conn = transfercmd(cmd, rest_offset)
        while data = conn.read(blocksize)
          yield(data)
        end
        conn.shutdown(Socket::SHUT_WR) rescue nil
        conn.read_timeout = 1
        conn.read rescue nil
      ensure
        conn.close if conn
      end
      voidresp
    end
  end
end
             
            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 net/ftp.rb, line 655
def retrlines(cmd) # :yield: line
  synchronize do
    with_binary(false) do
      begin
        conn = transfercmd(cmd)
        while line = conn.gets
          yield(line.sub(/\r?\n\z/, ""), !line.match(/\n\z/).nil?)
        end
        conn.shutdown(Socket::SHUT_WR) rescue nil
        conn.read_timeout = 1
        conn.read rescue nil
      ensure
        conn.close if conn
      end
      voidresp
    end
  end
end
             
            Removes a remote directory.
 
               # File net/ftp.rb, line 1204
def rmdir(dirname)
  voidcmd("RMD #{dirname}")
end
             
            Sends a command and returns the response.
 
               # File net/ftp.rb, line 492
def sendcmd(cmd)
  synchronize do
    putline(cmd)
    return getresp
  end
end
             
            Set the socket used to connect to the FTP server.
May raise FTPReplyError if get_greeting is false.
 
               # File net/ftp.rb, line 397
def set_socket(sock, get_greeting = true)
  synchronize do
    @sock = sock
    if get_greeting
      voidresp
    end
  end
end
             
            Issues a SITE command.
 
               # File net/ftp.rb, line 1301
def site(arg)
  cmd = "SITE " + arg
  voidcmd(cmd)
end
             
            Returns the size of the given (remote) filename.
 
               # File net/ftp.rb, line 1175
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
             
            Returns the status (STAT command).
when stat is invoked with pathname as a parameter it acts like list but a lot faster and over the same tcp session.
 
               # File net/ftp.rb, line 1248
def status(pathname = nil)
  line = pathname ? "STAT #{pathname}" : "STAT"
  if /[\r\n]/ =~ line
    raise ArgumentError, "A line must not contain CR or LF"
  end
  print "put: #{line}\n" if @debug_mode
  @sock.send(line + CRLF, Socket::MSG_OOB)
  return getresp
end
             
            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 net/ftp.rb, line 680
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
      begin
        conn = transfercmd(cmd)
        while buf = file.read(blocksize)
          conn.write(buf)
          yield(buf) if block_given?
        end
        conn.shutdown(Socket::SHUT_WR) rescue nil
        conn.read_timeout = 1
        conn.read rescue nil
      ensure
        conn.close if conn
      end
      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
             
            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 net/ftp.rb, line 716
def storlines(cmd, file) # :yield: line
  synchronize do
    with_binary(false) do
      begin
        conn = transfercmd(cmd)
        while buf = file.gets
          if buf[-2, 2] != CRLF
            buf = buf.chomp + CRLF
          end
          conn.write(buf)
          yield(buf) if block_given?
        end
        conn.shutdown(Socket::SHUT_WR) rescue nil
        conn.read_timeout = 1
        conn.read rescue nil
      ensure
        conn.close if conn
      end
      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