Class: CFA::Grub2::Default::KernelParams

Inherits:
Object
  • Object
show all
Defined in:
lib/cfa/grub2/default.rb

Overview

Represents kernel append line with helpers to easier modification. TODO: handle quoting, maybe have own lense to parse/serialize kernel

params?

Defined Under Namespace

Classes: ParamTree

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(line, key) ⇒ KernelParams

Returns a new instance of KernelParams.



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# File 'lib/cfa/grub2/default.rb', line 147

def initialize(line, key)
  @tree = ParamTree.new(line)
  @key = key
end

Instance Attribute Details

#key ⇒ Object (readonly)

Returns the value of attribute key.



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# File 'lib/cfa/grub2/default.rb', line 145

def key
  @key
end

Instance Method Details

#add_parameter(key, value, placer = AppendPlacer.new) ⇒ Object

Adds new parameter to kernel command line. Uses augeas placers. To replace value use ReplacePlacer



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# File 'lib/cfa/grub2/default.rb', line 194

def add_parameter(key, value, placer = AppendPlacer.new)
  element = placer.new_element(@tree)

  element[:operation] = :add
  element[:key]   = key
  element[:value] = value
end

#empty? ⇒ Boolean

checks if there is any parameter

Returns:

  • (Boolean) 


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# File 'lib/cfa/grub2/default.rb', line 162

def empty?
  serialize.empty?
end

#parameter(key) ⇒ Object

gets value for parameters.

Examples:

different values

line = "quite console=S0 console=S1 vga=0x400"
params = KernelParams.new(line)
params.parameter("quite") # => true
params.parameter("verbose") # => false
params.parameter("vga") # => "0x400"
params.parameter("console") # => ["S0", "S1"]

Returns:

  • possible values are ‘false` when parameter missing, `true` when parameter without value placed, string if single instance with value is there and array if multiple instance with values are there.



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# File 'lib/cfa/grub2/default.rb', line 180

def parameter(key)
  values = @tree.data
                .select { |e| e[:key] == key }
                .map { |e| e[:value] }

  return false if values.empty?
  return values if values.size > 1
  return true if values.first == true

  values.first
end

#remove_parameter(matcher) ⇒ Object

Removes parameter from kernel command line.

Parameters:

  • matcher (Matcher) —

    to find entry to remove



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# File 'lib/cfa/grub2/default.rb', line 204

def remove_parameter(matcher)
  @tree.data.select(&matcher).each { |e| e[:operation] = :remove }
end

#replace(line) ⇒ Object

replaces kernel params with passed line



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# File 'lib/cfa/grub2/default.rb', line 157

def replace(line)
  @tree = ParamTree.new(line)
end

#serialize ⇒ Object 



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# File 'lib/cfa/grub2/default.rb', line 152

def serialize
  @tree.to_string
end