Method: UUID#pseudo_mac_address

Defined in:
lib/uuid.rb

#pseudo_mac_address ⇒ Object

Generate a pseudo MAC address because we have no pure-ruby way to know the MAC address of the NIC this system uses. Note that cheating with pseudo arresses here is completely legal: see Section 4.5 of RFC4122 for details.

This implementation is shamelessly stolen from

https://github.com/spectra/ruby-uuid/blob/master/uuid.rb

Thanks spectra.



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# File 'lib/uuid.rb', line 215

def pseudo_mac_address
  sha1 = ::Digest::SHA1.new
  256.times do
    r = [rand(0x100000000)].pack "N"
    sha1.update r
  end
  str = sha1.digest
  r = rand 14 # 20-6
  node = str[r, 6] || str
  if RUBY_VERSION >= "1.9.0"
    nnode = node.bytes.to_a
    nnode[0] |= 0x01
    node = ''
    nnode.each { |s| node << s.chr }
  else
    node[0] |= 0x01 # multicast bit
  end
  node.bytes.collect{|b|b.to_s(16)}.join.hex & 0x7FFFFFFFFFFF
end