Protocol
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 151
def self.default_passive
@@default_passive
end
When true, connections are in passive mode per default.
Default: true.
# File net/ftp.rb, line 145
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 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 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 is true.
Username for login. If options is the string
“anonymous” and the options 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.
Number of seconds to wait for the connection to open. See #open_timeout for details.
Default: nil.
Number of seconds to wait for one block to be read. See #read_timeout for details.
Default: 60.
Number of seconds to wait for the TLS handshake. See #ssl_handshake_timeout
for details. Default: nil.
When true, all traffic to and from the server is written to
+$stdout+. Default: false.
# File net/ftp.rb, line 211
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 161
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 1230
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 883
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 278
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 1151
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 1344
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 1360
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 366
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 1137
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 1310
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 812
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 751
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 786
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 1273
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 907
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 598
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 1263
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 1195
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 1111
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 1089
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 1188
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 891
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 1293
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 1333
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 868
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 826
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 855
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 1210
def pwd
resp = sendcmd("PWD")
return parse257(resp)
end
Exits the FTP session.
# File net/ftp.rb, line 1284
def quit
voidcmd("QUIT")
end
Setter for the #read_timeout attribute.
# File net/ftp.rb, line 128
def read_timeout=(sec)
@sock.read_timeout = sec
@read_timeout = sec
end
Renames a file on the server.
# File net/ftp.rb, line 1126
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 629
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)
conn.read_timeout = 1
conn.read
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 654
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)
conn.read_timeout = 1
conn.read
ensure
conn.close if conn
end
voidresp
end
end
end
Removes a remote directory.
# File net/ftp.rb, line 1203
def rmdir(dirname)
voidcmd("RMD #{dirname}")
end
Sends a command and returns the response.
# File net/ftp.rb, line 491
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 396
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 1300
def site(arg)
cmd = "SITE " + arg
voidcmd(cmd)
end
Returns the size of the given (remote) filename.
# File net/ftp.rb, line 1174
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 1247
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 679
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)
conn.read_timeout = 1
conn.read
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 715
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)
conn.read_timeout = 1
conn.read
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