Class: Utel::Pdu

Inherits:
Object
  • Object
show all
Defined in:
lib/utel/pdu.rb

Class Method Summary collapse

Class Method Details

.decimal_semi_octets(number) ⇒ Object 



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# File 'lib/utel/pdu.rb', line 35

def decimal_semi_octets number
  reversed = ''
  number.to_s.split('').each_slice(2) do |pair|
    a,b = pair
    reversed << (b.nil? ? "F" : b) << a
  end
  reversed
end

.decode(string) ⇒ Object 



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# File 'lib/utel/pdu.rb', line 18

def decode string
  out = ''
  b = 0; d = 0
  string.scan(/.{2}/).each do |part|
    byte = part.to_i(16)
    c = ((byte & ((1 << 7-d)-1)) << d) | b;
    b = byte >> (7-d);
    out << c.chr
    d += 1
    if d == 7
      out << b.chr
      d = 0; b = 0
    end
  end
  out
end

.encode(string) ⇒ Object

Encode and decode pdu strings



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# File 'lib/utel/pdu.rb', line 5

def encode string
  out = ''
  for i in (0..string.length - 1) do
    t = i%8+1
    next if t == 8
    c = string[i] >> i%8
    b = (string[i+1] || 0) & ((1 << t)-1)
    c = (b << (8-t)) | c
    out << c.to_s(16).rjust(2, '0').upcase
  end
  out
end