REPARSE_JDATA_BUFFER

gistfile1.rb

  # The "old" way
  buf_target  = "\\??\\" << from_path
  wide_string = multi_to_wide(buf_target)[0..-3]

  # REPARSE_JDATA_BUFFER
  rdb = [
    "0xA0000003L".hex,      # ReparseTag (IO_REPARSE_TAG_MOUNT_POINT)
    wide_string.size + 12,  # ReparseDataLength
    0,                      # Reserved
    0,                      # SubstituteNameOffset
    wide_string.size,       # SubstituteNameLength
    wide_string.size + 2,   # PrintNameOffset
    0,                      # PrintNameLength
    wide_string             # PathBuffer
  ].pack('LSSSSSSa' + (wide_string.size + 4).to_s)

  # FFI attempt
  class REPARSE_JDATA_BUFFER < FFI::Struct
    layout(
      :ReparseTag, :ulong,
      :ReparseDataLength, :ushort,
      :Reserved, :ushort,
      :SubstituteNameOffset, :ushort,
      :SubstituteNameLength, :ushort,
      :PrintNameOffset, :ushort,
      :PrintNameLength, :ushort,
      :PathBuffer, [:char, 2]
    )
  end

  # UTF-16LE encoded string
  target = "\\??\\".encode('UTF-16LE') + from_path

  rdb = REPARSE_JDATA_BUFFER.new
  rdb[:ReparseTag] = 2684354563 # IO_REPARSE_TAG_MOUNT_POINT
  rdb[:ReparseDataLength] = target.size + 12
  rdb[:Reserved] = 0
  rdb[:SubstituteNameOffset] = 0
  rdb[:SubstituteNameLength] = target.size
  rdb[:PrintNameOffset] = target.size + 2
  rdb[:PrintNameLength] = 0
  rdb[:PathBuffer] # ??? How do I assign "target" here?