136 lines
2.4 KiB
Ruby
136 lines
2.4 KiB
Ruby
# frozen_string_literal: true
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module BBS
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module Telnet
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IAC = 255
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WILL = 251
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WONT = 252
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DO = 253
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DONT = 254
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SB = 250
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SE = 240
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ECHO_OPT = 1
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SGA_OPT = 3
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def negotiate
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send_raw [IAC, WILL, SGA_OPT].pack('C*')
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send_raw [IAC, WILL, ECHO_OPT].pack('C*')
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send_raw [IAC, DO, SGA_OPT].pack('C*')
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end
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def readkey
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loop do
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raw = @client.read(1)
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return nil if raw.nil?
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byte = raw.ord
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if byte == IAC
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absorb_iac
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next
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end
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case byte
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when 13, 10 then return :enter
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when 27 then return read_escape_sequence
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when 8, 127 then return :backspace
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when 3 then return :interrupt
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when 32..126 then return raw
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end
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end
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end
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def readline
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line = +""
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last_cr = false
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loop do
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raw = @client.read(1)
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return nil if raw.nil?
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byte = raw.ord
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if byte == IAC
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absorb_iac
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last_cr = false
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next
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end
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if byte == 13
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last_cr = true
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next
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end
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if byte == 10 || (byte == 0 && last_cr)
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write "\r\n"
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return line
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end
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last_cr = false
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next if byte == 0
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if byte == 8 || byte == 127
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unless line.empty?
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line.chop!
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write "\b \b"
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end
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next
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end
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next if byte < 32
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line << raw
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write raw
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end
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end
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def write(data)
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@client.write(data)
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rescue StandardError
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nil
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end
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private
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def read_escape_sequence
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b1 = @client.read(1)
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return :escape if b1.nil? || b1 != '['
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b2 = @client.read(1)
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return :escape if b2.nil?
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case b2
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when 'A' then :up
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when 'B' then :down
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when 'C' then :right
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when 'D' then :left
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else :escape
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end
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end
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def absorb_iac
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cmd = @client.read(1)
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return if cmd.nil?
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case cmd.ord
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when SB
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loop do
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b = @client.read(1)
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break if b.nil?
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if b.ord == IAC
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s = @client.read(1)
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break if s.nil? || s.ord == SE
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end
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end
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when WILL, WONT, DO, DONT
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@client.read(1)
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end
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end
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def send_raw(data)
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@client.write(data)
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rescue StandardError
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nil
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end
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end
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end
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