Class: FFI::Pointer

Inherits:
Object
  • Object
show all
Defined in:
lib/ffi/win32/extensions.rb

Instance Method Summary collapse

Instance Method Details

#read_array_of_string ⇒ Object

Returns an array of strings for char** types.



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# File 'lib/ffi/win32/extensions.rb', line 6

def read_array_of_string
  elements = []

  loc = self

  until (element = loc.read_pointer).null?
    elements << element.read_string
    loc += FFI::Type::POINTER.size
  end

  elements
end

#read_utf16string ⇒ Object 



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# File 'lib/ffi/win32/extensions.rb', line 58

def read_utf16string
  offset = 0
  offset += 2 while get_bytes(offset, 2) != "\x00\x00"
  get_bytes(0, offset).force_encoding("utf-16le").encode("utf-8")
end

#read_wide_string(num_bytes = size) ⇒ Object

Read num_bytes from a wide character string pointer. If this fails (typically because there are only null characters) then an empty string is returned instead.



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# File 'lib/ffi/win32/extensions.rb', line 23

def read_wide_string(num_bytes = size)
  read_bytes(num_bytes).force_encoding("UTF-16LE")
    .encode("UTF-8", invalid: :replace, undef: :replace)
    .split(0.chr).first.force_encoding(Encoding.default_external)
rescue
  ""
end

#read_wstring(num_wchars = nil) ⇒ Object

Read null-terminated Unicode strings.



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# File 'lib/ffi/win32/extensions.rb', line 33

def read_wstring(num_wchars = nil)
  if num_wchars.nil?
    # Find the length of the string
    length = 0
    last_char = nil
    while last_char != "\000\000"
      length += 1
      last_char = get_bytes(0, length * 2)[-2..-1]
    end

    num_wchars = length
  end

  wide_to_utf8(get_bytes(0, num_wchars * 2))
end

#wide_to_utf8(wstring) ⇒ Object 



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# File 'lib/ffi/win32/extensions.rb', line 49

def wide_to_utf8(wstring)
  # ensure it is actually UTF-16LE
  # Ruby likes to mark binary data as ASCII-8BIT
  wstring = wstring.force_encoding("UTF-16LE")

  # encode it all as UTF-8 and remove trailing CRLF and NULL characters
  wstring.encode("UTF-8").strip
end