Class: Net::SSH::Telnet
- Inherits:
-
Object
- Object
- Net::SSH::Telnet
- Defined in:
- lib/net/ssh/telnet.rb,
lib/net/ssh/telnet/version.rb
Overview
Net::SSH::Telnet
Provides a simple send/expect interface with an API almost identical to Net::Telnet. Please see Net::Telnet for main documentation. Only the differences are documented here.
Defined Under Namespace
Classes: TinyFactory
Constant Summary collapse
Instance Attribute Summary collapse
-
#channel ⇒ Object
readonly
The ssh session and channel we are using.
-
#ssh ⇒ Object
readonly
The ssh session and channel we are using.
Instance Method Summary collapse
-
#binmode(mode = nil) ⇒ Object
Turn newline conversion on (
mode
== false) or off (mode
== true), or return the current value (mode
is not specified). -
#binmode=(mode) ⇒ Object
Turn newline conversion on (false) or off (true).
-
#close ⇒ Object
Close the ssh channel, and also the entire ssh session if we opened it.
-
#cmd(options) ⇒ Object
Sends a command to the host.
-
#initialize(options, &blk) ⇒ Telnet
constructor
Creates a new Net::SSH::Telnet object.
-
#print(string) ⇒ Object
Sends
string
to the host. -
#prompt=(val) ⇒ Object
Change the standard prompt This is useful if you need a special prompt value for initializing the session, but want to use a different prompt for the rest of the session.
-
#puts(string) ⇒ Object
Sends
string
to the host. -
#waitfor(options) ⇒ Object
Read data from the host until a certain sequence is matched.
-
#write(string) ⇒ Object
Write
string
to the host.
Constructor Details
#initialize(options, &blk) ⇒ Telnet
Creates a new Net::SSH::Telnet object.
The API is similar to Net::Telnet, although you will need to pass in either an existing Net::SSH::Session object or a Username and Password, as shown below.
Note that unlike Net::Telnet there is no preprocess method automatically setting up options related to proper character translations, so if your remote ptty is configured differently than the typical linux one you may need to pass in a different terminator or call ‘stty’ remotely to set it into an expected mode. This is better explained by the author of perl’s Net::SSH::Expect here:
search.cpan.org/~bnegrao/Net-SSH-Expect-1.04/lib/Net/SSH/Expect.pod #IMPORTANT_NOTES_ABOUT_DEALING_WITH_SSH_AND_PSEUDO-TERMINALS
though for most installs the default LF should be fine. See example 5 below.
A new option is added to correct a misfeature of Net::Telnet. If you pass “FailEOF” => true, then if the remote end disconnects while you are still waiting for your match pattern then an EOFError is raised. Otherwise, it reverts to the same behaviour as Net::Telnet, which is just to return whatever data was sent so far, or nil if no data was returned so far. (This is a poor design because you can’t tell whether the expected pattern was successfully matched or the remote end disconnected unexpectedly, unless you perform a second match on the return string). See blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/11373 blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/11380
Example 1 - pass existing Net::SSH::Session object
ssh = Net::SSH.start("127.0.0.1",
:username=>"test123",
:password=>"pass456"
)
s = Net::SSH::Telnet.new(
"Dump_log" => "/dev/stdout",
"Session" => ssh
)
puts "Logged in"
p s.cmd("echo hello")
This is the most flexible way as it allows you to set up the SSH session using whatever authentication system you like. When done this way, calling Net::SSH::Telnet.new multiple times will create multiple channels, and #close will only close one channel.
In all later examples, calling #close will close the entire Net::SSH::Session object (and therefore drop the TCP connection)
Example 2 - pass host, username and password
s = Net::SSH::Telnet.new(
"Dump_log" => "/dev/stdout",
"Host" => "127.0.0.1",
"Username" => "test123",
"Password" => "pass456"
)
puts "Logged in"
puts s.cmd("echo hello")
Example 3 - pass open IO object, username and password (this is really just for compatibility with Net::Telnet Proxy feature)
require 'socket'
sock = TCPSocket.open("127.0.0.1",22)
s = Net::SSH::Telnet.new(
"Dump_log" => "/dev/stdout",
"Proxy" => sock,
"Username" => "test123",
"Password" => "pass456"
)
puts "Logged in"
puts s.cmd("echo hello")
Example 4 - pass a connection factory, host, username and password; Net::SSH will call #open(host,port) on this object. Included just because it was easy :-)
require 'socket'
s = Net::SSH::Telnet.new(
"Dump_log" => "/dev/stdout",
"Factory" => TCPSocket,
"Host" => "127.0.0.1",
"Username" => "test123",
"Password" => "pass456"
)
puts "Logged in"
puts s.cmd("echo hello")
Example 5 - connection to a SAN device running a customized NetBSD with different ptty defaults, it doesn’t convert LF -> CR+LF (see the man page for ‘stty’) and uses a custom prompt
s = Net::SSH::Telnet.new(
"Host" => "192.168.1.1",
"Username" => "test123",
"Password" => "pass456",
"Prompt" => %r{^\S+>\s.*$},
"Terminator" => "\r"
)
puts "Logged in"
puts s.cmd("show alerts")
New objects take a option
hash to set default settings. The keys for this options hash are all strings. A block can also be passed to constructor which will get executed after the first prompt is found.
Hash Parameters
-
"Host"
- a string to define the hostname to connect to(Default: “localhost”) -
"Port"
- port number to connect to(Default: 22) -
"Prompt"
- a regular expression to define the the prompt to expect(Default: /[$%#>] z/n ) -
"Timeout"
- the time out value passed on to Net::Ssh - also the default value for #waitfor(Default: 10) -
"Waittime"
- Max time to wait after a possible prompt it seen to make sure more data isn’t coming(Default: 0) -
"Terminator"
- This value is appended to all strings that are sent to #print.(Default: LF) -
"Binmode"
- Enable binary mode.(Default: false) -
"Output_log"
- A file name to open as an output log. -
"Dump_log"
- A file name to open to dump the entire session to. -
"Session"
- An existing Net::Ssh object for Net::Ssh::Telnet to use as its connection(See example 1) -
"Proxy"
- An open IO object to use as a Proxy(See example 3) -
"Factory"
- A connection factory to use to establish the connection. Net::Ssh::Telnet will call #open(host, post) on this object.(See example 4)
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# File 'lib/net/ssh/telnet.rb', line 157 def initialize(, &blk) # :yield: mesg @options = @options["Host"] = "localhost" unless @options.has_key?("Host") @options["Port"] = 22 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") @options["Terminator"] = LF unless @options.has_key?("Terminator") 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 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?("Session") @ssh = @options["Session"] @close_all = false elsif @options.has_key?("Proxy") @ssh = Net::SSH.start(nil, nil, :host_name => @options["Host"], # ignored :port => @options["Port"], # ignored :user => @options["Username"], :password => @options["Password"], :timeout => @options["Timeout"], :proxy => TinyFactory.new(@options["Proxy"]) ) @close_all = true 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 @ssh = Net::SSH.start(nil, nil, :host_name => @options["Host"], :port => @options["Port"], :user => @options["Username"], :password => @options["Password"], :timeout => @options["Timeout"], :proxy => @options["Factory"] ) @close_all = true rescue TimeoutError raise TimeoutError, "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 = "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 @buf = "" @eof = false @channel = nil @ssh.open_channel do |channel| channel.on_data { |ch,data| @buf << data } channel.on_extended_data { |ch,type,data| @buf << data if type == 1 } channel.on_close { @eof = true } channel.request_pty { |ch,success| if success == false raise "Failed to open ssh pty" end } channel.send_channel_request("shell") { |ch, success| if success @channel = ch waitfor(@options['Prompt'], &blk) return else raise "Failed to open ssh shell" end } end @ssh.loop end |
Instance Attribute Details
#channel ⇒ Object (readonly)
The ssh session and channel we are using.
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# File 'lib/net/ssh/telnet.rb', line 284 def channel @channel end |
#ssh ⇒ Object (readonly)
The ssh session and channel we are using.
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# File 'lib/net/ssh/telnet.rb', line 284 def ssh @ssh end |
Instance Method Details
#binmode(mode = nil) ⇒ Object
Turn newline conversion on (mode
== false) or off (mode
== true), or return the current value (mode
is not specified).
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# File 'lib/net/ssh/telnet.rb', line 288 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) ⇒ Object
Turn newline conversion on (false) or off (true).
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# File 'lib/net/ssh/telnet.rb', line 300 def binmode=(mode) if (true == mode or false == mode) @options["Binmode"] = mode else raise ArgumentError, "argument must be true or false" end end |
#close ⇒ Object
Close the ssh channel, and also the entire ssh session if we opened it.
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# File 'lib/net/ssh/telnet.rb', line 277 def close @channel.close if @channel @channel = nil @ssh.close if @close_all and @ssh end |
#cmd(options) ⇒ Object
Sends 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.
The command or other string will have the newline sequence appended to it.
The options
parameter takes a String or Hash. The Hash can be used to override the default settings that were established when the object was created.
A block can be provided to be called when the first prompt or “Match” is found.
Hash Parameters
-
"String"
- This string is sent over the connection via the #puts method. -
"Match"
- Passed to #waitfor as the “Prompt” parameter. See its defintion for details. -
"Timeout"
- Passed to #waitfor see its definition for details -
"FailEOF"
- Passed to #waitfor see its definition for details
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# File 'lib/net/ssh/telnet.rb', line 451 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 |
#print(string) ⇒ Object
Sends string
to the host.
This does not automatically append a newline to the string. Embedded newlines may be converted depending upon the values of binmode or terminator.
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# File 'lib/net/ssh/telnet.rb', line 407 def print(string) terminator = @options["Terminator"] if @options["Binmode"] self.write(string) else self.write(string.gsub(/\n/n, terminator)) end end |
#prompt=(val) ⇒ Object
Change the standard prompt This is useful if you need a special prompt value for initializing the session, but want to use a different prompt for the rest of the session
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# File 'lib/net/ssh/telnet.rb', line 420 def prompt= val @options["Prompt"] = val end |
#puts(string) ⇒ Object
Sends string
to the host.
Same as #print(), but appends a newline to the string.
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# File 'lib/net/ssh/telnet.rb', line 427 def puts(string) self.print(string + "\n") end |
#waitfor(options) ⇒ Object
Read data from the host until a certain sequence is matched.
The options
parameter takes an string keyed option Hash or a String.
A block can be provided to be called after the first prompt or match is found.
Hash Parameters
-
"Match"
- Regular expression to match -
"Prompt"
- Regular expression to match (Same as “Match”) -
"String"
- String to match -
"Timeout"
- Max time in seconds that can pass between packets (Default: 10 - set to false for no timeout) -
"Waittime"
- Max time to wait after a possible prompt it seen to make sure more data isn’t coming(Default: 0) -
"FailEOF"
- Raise EOFError if EOF is reached on the connection.(Default: false)
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# File 'lib/net/ssh/telnet.rb', line 323 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 = '' sock = @ssh.transport.socket until @ssh.transport.socket.available == 0 && @buf == "" && prompt === line && (@eof || (!sock.closed? && !IO::select([sock], nil, nil, waittime))) # @buf may have content if it was processed by Net::SSH before #waitfor # was called # The prompt is checked in case a waittime was specified, we've already # seen the prompt, but a protocol-level packet came through during the # above IO::select, causing us to reprocess if @buf == '' && (@ssh.transport.socket.available == 0) && !(prompt === line) && !IO::select([sock], nil, nil, time_out) raise Net::ReadTimeout, "timed out while waiting for more data" end _process_ssh if @buf != "" c = @buf; @buf = "" @dumplog.log_dump('<', c) if @options.has_key?("Dump_log") 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 @log.print(buf) if @options.has_key?("Output_log") line += buf yield buf if block_given? elsif @eof # End of file reached break if prompt === line raise EOFError if fail_eof if line == '' line = nil yield nil if block_given? end break end end line end |
#write(string) ⇒ Object
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.
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# File 'lib/net/ssh/telnet.rb', line 394 def write(string) @dumplog.log_dump('>', string) if @options.has_key?("Dump_log") # Add string to Net:SSH output queue @channel.send_data string # Call single instance of Net::SSH loop to process output queue _process_ssh end |