Class: PacketGen::Types::IntString

Inherits:
Object
  • Object
show all
Defined in:
lib/packetgen/types/int_string.rb

Overview

Provides a class for creating strings preceeded by their length as a Int. By default, a null string will have one byte length (length byte set to 0).

Author:

  • Sylvain Daubert

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(str = '', len_type = Int8) ⇒ IntString

Returns a new instance of IntString.

Parameters:

  • str (::String) (defaults to: '')
  • len_type (Class) (defaults to: Int8) —

    should be a PacketGen::Types::Int subclass



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# File 'lib/packetgen/types/int_string.rb', line 21

def initialize(str='', len_type=Int8)
  @string = Types::String.new(str)
  @length = len_type.new
  calc_length
end

Instance Attribute Details

#string ⇒ String

internal string

Returns:



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# File 'lib/packetgen/types/int_string.rb', line 17

def string
  @string
end

Instance Method Details

#calc_length ⇒ Integer

Set length from internal string length

Returns:

  • (Integer) 


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# File 'lib/packetgen/types/int_string.rb', line 58

def calc_length
  @length.read @string.length
end

#length ⇒ Integer

Returns:

  • (Integer) 


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# File 'lib/packetgen/types/int_string.rb', line 46

def length
  @length.to_i
end

#length=(l) ⇒ Integer

Parameters:

  • l (Integer)

Returns:

  • (Integer) 


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# File 'lib/packetgen/types/int_string.rb', line 40

def length=(l)
  @length.read l
  l
end

#read(str) ⇒ IntString

Returns self.

Parameters:

  • str (::String)

Returns:



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# File 'lib/packetgen/types/int_string.rb', line 29

def read(str)
  unless str[0, @length.width].size == @length.width
    raise ParseError, "String too short for type #{@length.type}"
  end
  @length.read str[0, @length.width]
  @string.read str[@length.width, @length.to_i]
  self
end

#sz ⇒ Integer

Give binary string length (including length field)

Returns:

  • (Integer) 


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# File 'lib/packetgen/types/int_string.rb', line 64

def sz
  to_s.size
end

#to_s ⇒ ::String

Get binary string

Returns:

  • (::String) 


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# File 'lib/packetgen/types/int_string.rb', line 52

def to_s
  @length.to_s << @string.to_s
end