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 434
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"]
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