Class: Net::Telnet
Relationships & Source Files | |
Inherits: | Object |
Defined in: | lib/net/telnet.rb, lib/net/telnet/version.rb |
Overview
Provides telnet client functionality.
This class also has, through delegation, all the methods of a socket object (by default, a TCPSocket
, but can be set by the Proxy
option to new()
). This provides methods such as close()
to end the session and sysread()
to read data directly from the host, instead of via the waitfor()
mechanism. Note that if you do use sysread()
directly when in telnet mode, you should probably pass the output through preprocess()
to extract telnet command sequences.
The telnet protocol allows a client to login remotely to a user account on a server and execute commands via a shell. The equivalent is done by creating a Telnet
class with the Host
option set to your host, calling #login() with your user and password, issuing one or more #cmd() calls, and then calling #close() to end the session. The #waitfor(), #print(), #puts(), and #write() methods, which #cmd() is implemented on top of, are only needed if you are doing something more complicated.
A Telnet
object can also be used to connect to non-telnet services, such as SMTP or HTTP. In this case, you normally want to provide the Port
option to specify the port to connect to, and set the Telnetmode
option to false to prevent the client from attempting to interpret telnet command sequences. Generally, #login() will not work with other protocols, and you have to handle authentication yourself.
For some protocols, it will be possible to specify the Prompt
option once when you create the Telnet
object and use #cmd() calls; for others, you will have to specify the response sequence to look for as the Match option to every #cmd() call, or call #puts() and #waitfor() directly; for yet others, you will have to use #sysread() instead of #waitfor() and parse server responses yourself.
It is worth noting that when you create a new Telnet
object, you can supply a proxy IO channel via the Proxy option. This can be used to attach the Telnet
object to other Telnet
objects, to already open sockets, or to any read-write IO object. This can be useful, for instance, for setting up a test fixture for unit testing.
Examples
Log in and send a command, echoing all output to stdout
localhost = Net::Telnet::new("Host" => "localhost",
"Timeout" => 10,
"Prompt" => /[$%#>] \z/n)
localhost.login("username", "password") { |c| print c }
localhost.cmd("command") { |c| print c }
localhost.close
Check a POP server to see if you have mail
pop = Net::Telnet::new("Host" => "your_destination_host_here",
"Port" => 110,
"Telnetmode" => false,
"Prompt" => /^\+OK/n)
pop.cmd("user " + "your_username_here") { |c| print c }
pop.cmd("pass " + "your_password_here") { |c| print c }
pop.cmd("list") { |c| print c }
References
There are a large number of RFCs relevant to the Telnet
protocol. RFCs 854-861 define the base protocol. For a complete listing of relevant RFCs, see www.omnifarious.org/~hopper/technical/telnet-rfc.html
Constant Summary
-
ABORT =
Internal use only
“357” # “xef” # end of record (transparent mode)
238.chr
-
AO =
Internal use only
“366” # “xf6” # are you there
245.chr
-
AYT =
Internal use only
“367” # “xf7” # erase the current character
246.chr
-
BREAK =
Internal use only
“364” # “xf4” # interrupt process–permanently
243.chr
-
CR =
Internal use only
# File 'lib/net/telnet.rb', line 162"\015"
-
DM =
Internal use only
“363” # “xf3” # break
242.chr
-
DO =
Internal use only
“376” # “xfe” # you are not to use option
253.chr
-
DONT =
Internal use only
“377” # “xff” # interpret as command
254.chr
-
EC =
Internal use only
“370” # “xf8” # erase the current line
247.chr
-
EL =
Internal use only
“371” # “xf9” # you may reverse the line
248.chr
-
EOF =
Internal use only
“355” # “xed” # Suspend process
236.chr
-
EOL =
Internal use only
# File 'lib/net/telnet.rb', line 164CR + LF
-
EOR =
Internal use only
“360” # “xf0” # end sub negotiation
239.chr
-
GA =
Internal use only
“372” # “xfa” # interpret as subnegotiation
249.chr
-
IAC =
Internal use only
# File 'lib/net/telnet.rb', line 97255.chr
-
IP =
Internal use only
“365” # “xf5” # abort output–but let prog finish
244.chr
-
LF =
Internal use only
# File 'lib/net/telnet.rb', line 163"\012"
-
NOP =
Internal use only
“362” # “xf2” # data mark–for connect. cleaning
241.chr
-
NULL =
Internal use only
“377” # “xff” # Extended-Options-List
"\000"
-
OPT_3270REGIME =
Internal use only
“034” # “x1c” # Terminal Location Number
29.chr
-
OPT_AUTHENTICATION =
Internal use only
“$” # “x24” # Environment Option
37.chr
-
OPT_BINARY =
Internal use only
“362” # “xf2” # for telfunc calls
0.chr
-
OPT_BM =
Internal use only
“022” # “x12” # Logout
19.chr
-
OPT_DET =
Internal use only
“023” # “x13” # Byte Macro
20.chr
-
OPT_ECHO =
Internal use only
“000” # “x00” # Binary Transmission
1.chr
-
OPT_ENCRYPT =
Internal use only
“%” # “x25” # Authentication Option
38.chr
-
OPT_EOR =
Internal use only
“030” # “x18” # Terminal Type
25.chr
-
OPT_EXOPL =
Internal use only
“‘” # “x27” # New Environment Option
255.chr
-
OPT_LFLOW =
Internal use only
“ ” # “x20” # Terminal Speed
33.chr
-
OPT_LINEMODE =
Internal use only
“!” # “x21” # Remote Flow Control
34.chr
-
OPT_LOGOUT =
Internal use only
“021” # “x11” # Extended ASCII
18.chr
-
OPT_NAMS =
Internal use only
“003” # “x03” # Suppress Go Ahead
4.chr
-
OPT_NAOCRD =
Internal use only
“t” # “x09” # Output Page Size
10.chr
-
OPT_NAOFFD =
Internal use only
“f” # “x0c” # Output Horizontal Tab Disposition
13.chr
-
OPT_NAOHTD =
Internal use only
“v” # “x0b” # Output Horizontal Tab Stops
12.chr
-
OPT_NAOHTS =
Internal use only
“n” # “x0a” # Output Carriage-Return Disposition
11.chr
-
OPT_NAOL =
Internal use only
“a” # “x07” # Remote Controlled Trans and Echo
8.chr
-
OPT_NAOLFD =
Internal use only
“017” # “x0f” # Output Vertical Tab Disposition
16.chr
-
OPT_NAOP =
Internal use only
“010” # “x08” # Output Line Width
9.chr
-
OPT_NAOVTD =
Internal use only
“016” # “x0e” # Output Vertical Tabstops
15.chr
-
OPT_NAOVTS =
Internal use only
“r” # “x0d” # Output Formfeed Disposition
14.chr
-
OPT_NAWS =
Internal use only
“036” # “x1e” # X.3 PAD
31.chr
-
OPT_NEW_ENVIRON =
Internal use only
“&” # “x26” # Encryption Option
39.chr
-
OPT_OLD_ENVIRON =
Internal use only
“#” # “x23” # X Display Location
36.chr
-
OPT_OUTMRK =
Internal use only
“032” # “x1a” # TACACS User Identification
27.chr
-
OPT_RCP =
Internal use only
“001” # “x01” # Echo
2.chr
-
OPT_RCTE =
Internal use only
“006” # “x06” # Timing Mark
7.chr
-
OPT_SGA =
Internal use only
“002” # “x02” # Reconnection
3.chr
-
OPT_SNDLOC =
Internal use only
“026” # “x16” # SUPDUP Output
23.chr
-
OPT_STATUS =
Internal use only
“004” # “x04” # Approx Message Size Negotiation
5.chr
-
OPT_SUPDUP =
Internal use only
“024” # “x14” # Data Entry Terminal
21.chr
-
OPT_SUPDUPOUTPUT =
Internal use only
“025” # “x15” # SUPDUP
22.chr
-
OPT_TM =
Internal use only
“005” # “x05” # Status
6.chr
-
OPT_TSPEED =
Internal use only
“037” # “x1f” # Negotiate About Window Size
32.chr
-
OPT_TTYLOC =
Internal use only
“e” # “x1b” # Output Marking
28.chr
-
OPT_TTYPE =
Internal use only
“027” # “x17” # Send Location
24.chr
-
OPT_TUID =
Internal use only
“031” # “x19” # End of Record
26.chr
-
OPT_X3PAD =
Internal use only
“035” # “x1d” #
Telnet
3270 Regime30.chr
-
OPT_XASCII =
Internal use only
“020” # “x10” # Output Linefeed Disposition
17.chr
-
OPT_XDISPLOC =
Internal use only
“"” # “x22” # Linemode
35.chr
-
REVISION =
Internal use only
# File 'lib/net/telnet.rb', line 165'$Id$'
-
SB =
Internal use only
“373” # “xfb” # I will use option
250.chr
-
SE =
Internal use only
“361” # “xf1” # nop
240.chr
-
SUSP =
Internal use only
“356” # “xee” # Abort process
237.chr
-
SYNCH =
Internal use only
“354” # “xec” # End of file
242.chr
-
VERSION =
# File 'lib/net/telnet/version.rb', line 3"0.2.0"
-
WILL =
Internal use only
“374” # “xfc” # I won’t use option
251.chr
-
WONT =
Internal use only
“375” # “xfd” # please, you use option
252.chr
Class Method Summary
-
.new(options) ⇒ Telnet
constructor
Creates a new
Telnet
object.
Instance Attribute Summary
-
#sock
readonly
The socket the
Telnet
object is using.
Instance Method Summary
-
#binmode(mode = nil)
Turn newline conversion on (
mode
== false) or off (mode
== true), or return the current value (mode
is not specified). -
#binmode=(mode)
Turn newline conversion on (false) or off (true).
-
#close
Closes the connection.
-
#cmd(options)
Send a command to the host.
-
#login(options, password = nil)
Login to the host with a given username and password.
-
#preprocess(string)
Preprocess received data from the host.
-
#print(string)
Sends a string to the host.
-
#puts(string)
Sends a string to the host.
-
#telnetmode(mode = nil)
Set telnet command interpretation on (
mode
== true) or off (mode
== false), or return the current value (mode
not provided). -
#telnetmode=(mode)
Turn telnet command interpretation on (true) or off (false).
-
#waitfor(options)
Read data from the host until a certain sequence is matched.
-
#write(string)
Write
string
to the host.
Constructor Details
.new(options) ⇒ Telnet
Creates a new Telnet
object.
Attempts to connect to the host (unless the Proxy option is provided: see below). If a block is provided, it is yielded status messages on the attempt to connect to the server, of the form:
Trying localhost...
Connected to localhost.
options
is a hash of options. The following example lists all options and their default values.
host = Net::Telnet::new(
"Host" => "localhost", # default: "localhost"
"Port" => 23, # default: 23
"Binmode" => false, # default: false
"Output_log" => "output_log", # default: nil (no output)
"Dump_log" => "dump_log", # default: nil (no output)
"Prompt" => /[$%#>] \z/n, # default: /[$%#>] \z/n
"Telnetmode" => true, # default: true
"Timeout" => 10, # default: 10
# if ignore timeout then set "Timeout" to false.
"Waittime" => 0, # default: 0
"Proxy" => proxy # default: nil
# proxy is Net::Telnet or IO object
)
The options have the following meanings:
- Host
-
the hostname or IP address of the host to connect to, as a String. Defaults to “localhost”.
- Port
-
the port to connect to. Defaults to 23.
- Binmode
-
if false (the default), newline substitution is performed. Outgoing LF is converted to CRLF, and incoming CRLF is converted to LF. If true, this substitution is not performed. This value can also be set with the #binmode() method. The outgoing conversion only applies to the #puts() and #print() methods, not the #write() method. The precise nature of the newline conversion is also affected by the telnet options SGA and BIN.
- Output_log
-
the name of the file to write connection status messages and all received traffic to. In the case of a proper Telnet session, this will include the client input as echoed by the host; otherwise, it only includes server responses. Output is appended verbatim to this file. By default, no output log is kept.
- Dump_log
-
as for Output_log, except that output is written in hexdump format (16 bytes per line as hex pairs, followed by their printable equivalent), with connection status messages preceded by ‘#’, sent traffic preceded by ‘>’, and received traffic preceded by ‘<’. By default, not dump log is kept.
- Prompt
-
a regular expression matching the host’s command-line prompt sequence. This is needed by the Telnet class to determine when the output from a command has finished and the host is ready to receive a new command. By default, this regular expression is /[$%#>] z/n.
- Telnetmode
-
a boolean value, true by default. In telnet mode, traffic received from the host is parsed for special command sequences, and these sequences are escaped in outgoing traffic sent using #puts() or #print() (but not #write()). If you are using the Net::Telnet object to connect to a non-telnet service (such as SMTP or POP), this should be set to “false” to prevent undesired data corruption. This value can also be set by the #telnetmode() method.
- Timeout
-
the number of seconds to wait before timing out both the initial attempt to connect to host (in this constructor), which raises a Net::OpenTimeout, and all attempts to read data from the host, which raises a Net::ReadTimeout (in #waitfor(), #cmd(), and #login()). The default value is 10 seconds. You can disable the timeout by setting this value to false. In this case, the connect attempt will eventually timeout on the underlying connect(2) socket call with an Errno::ETIMEDOUT error (but generally only after a few minutes), but other attempts to read data from the host will hang indefinitely if no data is forthcoming.
- Waittime
-
the amount of time to wait after seeing what looks like a prompt (that is, received data that matches the Prompt option regular expression) to see if more data arrives. If more data does arrive in this time, Net::Telnet assumes that what it saw was not really a prompt. This is to try to avoid false matches, but it can also lead to missing real prompts (if, for instance, a background process writes to the terminal soon after the prompt is displayed). By default, set to 0, meaning not to wait for more data.
- Proxy
-
a proxy object to used instead of opening a direct connection to the host. Must be either another Net::Telnet object or an IO object. If it is another Net::Telnet object, this instance will use that one’s socket for communication. If an IO object, it is used directly for communication. Any other kind of object will cause an error to be raised.
# File 'lib/net/telnet.rb', line 273
def initialize( ) # :yield: mesg @options = @options["Host"] = "localhost" unless @options.has_key?("Host") @options["Port"] = 23 unless @options.has_key?("Port") @options["Prompt"] = /[$%#>] \z/n unless @options.has_key?("Prompt") @options["Timeout"] = 10 unless @options.has_key?("Timeout") @options["Waittime"] = 0 unless @options.has_key?("Waittime") unless @options.has_key?("Binmode") @options["Binmode"] = false else unless (true == @options["Binmode"] or false == @options["Binmode"]) raise ArgumentError, "Binmode option must be true or false" end end unless @options.has_key?("Telnetmode") @options["Telnetmode"] = true else unless (true == @options["Telnetmode"] or false == @options["Telnetmode"]) raise ArgumentError, "Telnetmode option must be true or false" end end @telnet_option = { "SGA" => false, "BINARY" => false } if @options.has_key?("Output_log") @log = File.open(@options["Output_log"], 'a+') @log.sync = true @log.binmode end if @options.has_key?("Dump_log") @dumplog = File.open(@options["Dump_log"], 'a+') @dumplog.sync = true @dumplog.binmode def @dumplog.log_dump(dir, x) # :nodoc: len = x.length addr = 0 offset = 0 while 0 < len if len < 16 line = x[offset, len] else line = x[offset, 16] end hexvals = line.unpack('H*')[0] hexvals += ' ' * (32 - hexvals.length) hexvals = format("%s %s %s %s " * 4, *hexvals.unpack('a2' * 16)) line = line.gsub(/[\000-\037\177-\377]/n, '.') printf "%s 0x%5.5x: %s%s\n", dir, addr, hexvals, line addr += 16 offset += 16 len -= 16 end print "\n" end end if @options.has_key?("Proxy") if @options["Proxy"].kind_of?(Net::Telnet) @sock = @options["Proxy"].sock elsif @options["Proxy"].kind_of?(IO) @sock = @options["Proxy"] else raise "Error: Proxy must be an instance of Net::Telnet or IO." end else = "Trying " + @options["Host"] + "...\n" yield( ) if block_given? @log.write( ) if @options.has_key?("Output_log") @dumplog.log_dump('#', ) if @options.has_key?("Dump_log") begin if @options["Timeout"] == false @sock = TCPSocket.open(@options["Host"], @options["Port"]) else Timeout.timeout(@options["Timeout"], Net::OpenTimeout) do @sock = TCPSocket.open(@options["Host"], @options["Port"]) end end rescue Net::OpenTimeout raise Net::OpenTimeout, "timed out while opening a connection to the host" rescue @log.write($ERROR_INFO.to_s + "\n") if @options.has_key?("Output_log") @dumplog.log_dump('#', $ERROR_INFO.to_s + "\n") if @options.has_key?("Dump_log") raise end @sock.sync = true @sock.binmode = "Connected to " + @options["Host"] + ".\n" yield( ) if block_given? @log.write( ) if @options.has_key?("Output_log") @dumplog.log_dump('#', ) if @options.has_key?("Dump_log") end end
Instance Attribute Details
#sock (readonly)
The socket the Telnet
object is using. Note that this object becomes a delegate of the Telnet
object, so normally you invoke its methods directly on the Telnet
object.
# File 'lib/net/telnet.rb', line 374
attr_reader :sock
Instance Method Details
#binmode(mode = nil)
Turn newline conversion on (mode
== false) or off (mode
== true), or return the current value (mode
is not specified).
# File 'lib/net/telnet.rb', line 405
def binmode(mode = nil) case mode when nil @options["Binmode"] when true, false @options["Binmode"] = mode else raise ArgumentError, "argument must be true or false" end end
#binmode=(mode)
Turn newline conversion on (false) or off (true).
# File 'lib/net/telnet.rb', line 417
def binmode=(mode) if (true == mode or false == mode) @options["Binmode"] = mode else raise ArgumentError, "argument must be true or false" end end
#close
Closes the connection
# File 'lib/net/telnet.rb', line 757
def close @sock.close end
#cmd(options)
Send a command to the host.
More exactly, sends a string to the host, and reads in all received data until is sees the prompt or other matched sequence.
If a block is given, the received data will be yielded to it as it is read in. Whether a block is given or not, the received data will be return as a string. Note that the received data includes the prompt and in most cases the host’s echo of our command.
options
is either a String, specified the string or command to send to the host; or it is a hash of options. If a hash, the following options can be specified:
- String
-
the command or other string to send to the host.
- Match
-
a regular expression, the sequence to look for in the received data before returning. If not specified, the Prompt option value specified when this instance was created will be used, or, failing that, the default prompt of /[$%#>] z/n.
- Timeout
-
the seconds to wait for data from the host before raising a Timeout error. If not specified, the Timeout option value specified when this instance was created will be used, or, failing that, the default value of 10 seconds.
The command or other string will have the newline sequence appended to it.
# File 'lib/net/telnet.rb', line 678
def cmd( ) # :yield: recvdata match = @options["Prompt"] time_out = @options["Timeout"] fail_eof = @options["FailEOF"] if .kind_of?(Hash) string = ["String"] match = ["Match"] if .has_key?("Match") time_out = ["Timeout"] if .has_key?("Timeout") fail_eof = ["FailEOF"] if .has_key?("FailEOF") else string = end self.puts(string) if block_given? waitfor({"Prompt" => match, "Timeout" => time_out, "FailEOF" => fail_eof}){|c| yield c } else waitfor({"Prompt" => match, "Timeout" => time_out, "FailEOF" => fail_eof}) end end
#login(options, password = nil)
Login to the host with a given username and password.
The username and password can either be provided as two string arguments in that order, or as a hash with keys “Name” and “Password”.
This method looks for the strings “login” and “Password” from the host to determine when to send the username and password. If the login sequence does not follow this pattern (for instance, you are connecting to a service other than telnet), you will need to handle login yourself.
The password can be omitted, either by only provided one String argument, which will be used as the username, or by providing a has that has no “Password” key. In this case, the method will not look for the “Password:” prompt; if it is sent, it will have to be dealt with by later calls.
The method returns all data received during the login process from the host, including the echoed username but not the password (which the host should not echo). If a block is passed in, this received data is also yielded to the block as it is received.
# File 'lib/net/telnet.rb', line 722
def login(, password = nil) # :yield: recvdata login_prompt = /[Ll]ogin[: ]*\z/n password_prompt = /[Pp]ass(?:word|phrase)[: ]*\z/n if .kind_of?(Hash) username = ["Name"] password = ["Password"] login_prompt = ["LoginPrompt"] if ["LoginPrompt"] password_prompt = ["PasswordPrompt"] if ["PasswordPrompt"] else username = end if block_given? line = waitfor(login_prompt){|c| yield c } if password line += cmd({"String" => username, "Match" => password_prompt}){|c| yield c } line += cmd(password){|c| yield c } else line += cmd(username){|c| yield c } end else line = waitfor(login_prompt) if password line += cmd({"String" => username, "Match" => password_prompt}) line += cmd(password) else line += cmd(username) end end line end
#preprocess(string)
Preprocess received data from the host.
Performs newline conversion and detects telnet command sequences. Called automatically by #waitfor(). You should only use this method yourself if you have read input directly using sysread() or similar, and even then only if in telnet mode.
# File 'lib/net/telnet.rb', line 431
def preprocess(string) # combine CR+NULL into CR string = string.gsub(/#{CR}#{NULL}/no, CR) if @options["Telnetmode"] # combine EOL into "\n" string = string.gsub(/#{EOL}/no, "\n") unless @options["Binmode"] # remove NULL string = string.gsub(/#{NULL}/no, '') unless @options["Binmode"] string.gsub(/#{IAC}( [#{IAC}#{AO}#{AYT}#{DM}#{IP}#{NOP}]| [#{DO}#{DONT}#{WILL}#{WONT}] [#{OPT_BINARY}-#{OPT_NEW_ENVIRON}#{OPT_EXOPL}]| #{SB}[^#{IAC}]*#{IAC}#{SE} )/xno) do if IAC == $1 # handle escaped IAC characters IAC elsif AYT == $1 # respond to "IAC AYT" (are you there) self.write("nobody here but us pigeons" + EOL) '' elsif DO[0] == $1[0] # respond to "IAC DO x" if OPT_BINARY[0] == $1[1] @telnet_option["BINARY"] = true self.write(IAC + WILL + OPT_BINARY) else self.write(IAC + WONT + $1[1..1]) end '' elsif DONT[0] == $1[0] # respond to "IAC DON'T x" with "IAC WON'T x" self.write(IAC + WONT + $1[1..1]) '' elsif WILL[0] == $1[0] # respond to "IAC WILL x" if OPT_BINARY[0] == $1[1] self.write(IAC + DO + OPT_BINARY) elsif OPT_ECHO[0] == $1[1] self.write(IAC + DO + OPT_ECHO) elsif OPT_SGA[0] == $1[1] @telnet_option["SGA"] = true self.write(IAC + DO + OPT_SGA) else self.write(IAC + DONT + $1[1..1]) end '' elsif WONT[0] == $1[0] # respond to "IAC WON'T x" if OPT_ECHO[0] == $1[1] self.write(IAC + DONT + OPT_ECHO) elsif OPT_SGA[0] == $1[1] @telnet_option["SGA"] = false self.write(IAC + DONT + OPT_SGA) else self.write(IAC + DONT + $1[1..1]) end '' else '' end end end
#print(string)
Sends a string to the host.
This does not automatically append a newline to the string. Embedded newlines may be converted and telnet command sequences escaped depending upon the values of telnetmode, binmode, and telnet options set by the host.
# File 'lib/net/telnet.rb', line 625
def print(string) string = string.gsub(/#{IAC}/no, IAC + IAC) if @options["Telnetmode"] if @options["Binmode"] self.write(string) else if @telnet_option["BINARY"] and @telnet_option["SGA"] # IAC WILL SGA IAC DO BIN send EOL --> CR self.write(string.gsub(/\n/n, CR)) elsif @telnet_option["SGA"] # IAC WILL SGA send EOL --> CR+NULL self.write(string.gsub(/\n/n, CR + NULL)) else # NONE send EOL --> CR+LF self.write(string.gsub(/\n/n, EOL)) end end end
#puts(string)
Sends a string to the host.
Same as #print(), but appends a newline to the string.
# File 'lib/net/telnet.rb', line 647
def puts(string) self.print(string + "\n") end
#telnetmode(mode = nil)
Set telnet command interpretation on (mode
== true) or off (mode
== false), or return the current value (mode
not provided). It should be on for true telnet sessions, off if using Telnet
to connect to a non-telnet service such as SMTP.
# File 'lib/net/telnet.rb', line 381
def telnetmode(mode = nil) case mode when nil @options["Telnetmode"] when true, false @options["Telnetmode"] = mode else raise ArgumentError, "argument must be true or false, or missing" end end
#telnetmode=(mode)
Turn telnet command interpretation on (true) or off (false). It should be on for true telnet sessions, off if using Telnet
to connect to a non-telnet service such as SMTP.
# File 'lib/net/telnet.rb', line 395
def telnetmode=(mode) if (true == mode or false == mode) @options["Telnetmode"] = mode else raise ArgumentError, "argument must be true or false" end end
#waitfor(options)
Read data from the host until a certain sequence is matched.
If a block is given, the received data will be yielded as it is read in (not necessarily all in one go), or nil if EOF occurs before any data is received. Whether a block is given or not, all data read will be returned in a single string, or again nil if EOF occurs before any data is received. Note that received data includes the matched sequence we were looking for.
options
can be either a regular expression or a hash of options. If a regular expression, this specifies the data to wait for. If a hash, this can specify the following options:
- Match
-
a regular expression, specifying the data to wait for.
- Prompt
-
as for Match; used only if Match is not specified.
- String
-
as for Match, except a string that will be converted into a regular expression. Used only if Match and Prompt are not specified.
- Timeout
-
the number of seconds to wait for data from the host before raising a Timeout::Error. If set to false, no timeout will occur. If not specified, the Timeout option value specified when this instance was created will be used, or, failing that, the default value of 10 seconds.
- Waittime
-
the number of seconds to wait after matching against the input data to see if more data arrives. If more data arrives within this time, we will judge ourselves not to have matched successfully, and will continue trying to match. If not specified, the Waittime option value specified when this instance was created will be used, or, failing that, the default value of 0 seconds, which means not to wait for more input.
- FailEOF
-
if true, when the remote end closes the connection then an EOFError will be raised. Otherwise, defaults to the old behaviour that the function will return whatever data has been received already, or nil if nothing was received.
# File 'lib/net/telnet.rb', line 528
def waitfor( ) # :yield: recvdata time_out = @options["Timeout"] waittime = @options["Waittime"] fail_eof = @options["FailEOF"] if .kind_of?(Hash) prompt = if .has_key?("Match") ["Match"] elsif .has_key?("Prompt") ["Prompt"] elsif .has_key?("String") Regexp.new( Regexp.quote( ["String"]) ) end time_out = ["Timeout"] if .has_key?("Timeout") waittime = ["Waittime"] if .has_key?("Waittime") fail_eof = ["FailEOF"] if .has_key?("FailEOF") else prompt = end if time_out == false time_out = nil end line = '' buf = '' rest = '' until(prompt === line and not @sock.wait_readable(waittime)) unless @sock.wait_readable(time_out) raise Net::ReadTimeout, "timed out while waiting for more data" end begin c = @sock.readpartial(1024 * 1024) @dumplog.log_dump('<', c) if @options.has_key?("Dump_log") if @options["Telnetmode"] c = rest + c if Integer(c.rindex(/#{IAC}#{SE}/no) || 0) < Integer(c.rindex(/#{IAC}#{SB}/no) || 0) buf = preprocess(c[0 ... c.rindex(/#{IAC}#{SB}/no)]) rest = c[c.rindex(/#{IAC}#{SB}/no) .. -1] elsif pt = c.rindex(/#{IAC}[^#{IAC}#{AO}#{AYT}#{DM}#{IP}#{NOP}]?\z/no) || c.rindex(/\r\z/no) buf = preprocess(c[0 ... pt]) rest = c[pt .. -1] else buf = preprocess(c) rest = '' end else # Not Telnetmode. # # We cannot use preprocess() on this data, because that # method makes some Telnetmode-specific assumptions. buf = rest + c rest = '' unless @options["Binmode"] if pt = buf.rindex(/\r\z/no) buf = buf[0 ... pt] rest = buf[pt .. -1] end buf.gsub!(/#{EOL}/no, "\n") end end @log.print(buf) if @options.has_key?("Output_log") line += buf yield buf if block_given? rescue EOFError # End of file reached raise if fail_eof if line == '' line = nil yield nil if block_given? end break end end line end
#write(string)
Write string
to the host.
Does not perform any conversions on string
. Will log string
to the dumplog, if the Dump_log option is set.
# File 'lib/net/telnet.rb', line 610
def write(string) length = string.length while 0 < length @sock.wait_writable @dumplog.log_dump('>', string[-length..-1]) if @options.has_key?("Dump_log") length -= @sock.syswrite(string[-length..-1]) end end