Class: Samplelines

Inherits:
Object
  • Object
show all
Defined in:
lib/samplelines.rb,
lib/samplelines/version.rb

Defined Under Namespace

Classes: MultiFile

Constant Summary collapse

VERSION = 
"0.0.1"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(argv = ARGV) ⇒ Samplelines

Returns a new instance of Samplelines.



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# File 'lib/samplelines.rb', line 45

def initialize(argv = ARGV)
  self.orig_argv = argv.dup
  self.remaining_argv = argv
  
  self.slop = self.create_slop!
  self.options = parse_options(self.remaining_argv)
  
end

Instance Attribute Details

#input ⇒ Object

Returns the value of attribute input.



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# File 'lib/samplelines.rb', line 43

def input
  @input
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/samplelines.rb', line 43

def options
  @options
end

#orig_argv ⇒ Object

Returns the value of attribute orig_argv.



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# File 'lib/samplelines.rb', line 43

def orig_argv
  @orig_argv
end

#remaining_argv ⇒ Object

Returns the value of attribute remaining_argv.



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# File 'lib/samplelines.rb', line 43

def remaining_argv
  @remaining_argv
end

#slop ⇒ Object

Returns the value of attribute slop.



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# File 'lib/samplelines.rb', line 43

def slop
  @slop
end

Instance Method Details

#create_picker(opts) ⇒ Object 



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# File 'lib/samplelines.rb', line 89

def create_picker(opts)
  if opts[:percent]
    cutoff = opts[:percent].to_i
    out_of = 100
  elsif opts[:'one-in']
    cutoff = 1
    out_of = opts[:'one-in'].to_i
  else
    raise "Samplelines must take either -p or -1"
  end
  ->() do
    rand(out_of) < cutoff
  end
end

#create_slop! ⇒ Object 



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# File 'lib/samplelines.rb', line 104

def create_slop!
  return Slop.new(:strict=>true) do
    banner "samplelines [options] [filename(s) and/or STDIN and/or STDERR]"

    on 'v', 'version', 'print version info'
    on 'h', 'help',    'print usage information'
    on 'p', 'percent', 'set % chance of a line being output [trumps use of -1]', :argument=>true
    on '1', 'one-in',  'compute odds of outputing a line as 1 out of every N', :argument=>true
    on 'm', 'max', 'return at most this many lines', :argument => true
    on 't', 'time', 'stop running after N seconds', :argument => true
  end
end

#execute ⇒ Object 



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# File 'lib/samplelines.rb', line 55

def execute
  if options[:version]
    $stderr.puts "Samplelines version #{Samplelines::VERSION}"
    return
  end
  
  if options[:help] or orig_argv.empty?
    $stderr.puts slop.help
    return
  end
  
  input = Samplelines::MultiFile.new(self.remaining_argv)
  picker = create_picker(options)
  max = options[:max] ? options[:max].to_i : nil
  
  timer_finished = if options[:time]
                    seconds = options[:time].to_i
                    start_time = Time.new
                    ->() { Time.new - start_time > seconds}
                  else
                    ->() { false }
                  end
  
  total = 0
  input.each do |l|
    if picker.call
      total += 1
      print l 
    end
    return if max and total == max
    return if timer_finished.call
  end
end

#parse_options(argv) ⇒ Object 



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# File 'lib/samplelines.rb', line 117

def parse_options(argv)

  begin
    self.slop.parse!(argv)
  rescue Slop::Error => e
    $stderr.puts "Error: #{e.message}"
    $stderr.puts "Exiting..."
    $stderr.puts
    $stderr.puts slop.help
    exit 1
  end

  return self.slop.to_hash
end