Class: Rbkb::Cli::Rstrings

Inherits:
Executable show all
Defined in:
lib/rbkb/cli/rstrings.rb

Overview

Copyright 2009 emonti at matasano.com See README.rdoc for license information

rstrings is Unix “strings” in ruby… with some extra stuff

Instance Attribute Summary

Attributes inherited from Executable

#argv, #exit_status, #oparse, #opts, #stderr, #stdin, #stdout

Instance Method Summary collapse

Methods inherited from Executable

#bail, #bail_args, #exit, run

Constructor Details

#initialize(*args) ⇒ Rstrings

Returns a new instance of Rstrings.



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# File 'lib/rbkb/cli/rstrings.rb', line 8

def initialize(*args)
  super(*args) do |this|
    {
      :start_off => 0, 
      :end_off => -1, 
      :encoding => :both, 
      :minimum => 6,
      :align => nil,
      :indat => Array.new,
      :fnames => Array.new,
    }.each {|k,v| this.opts[k] ||= v }

    yield this if block_given?
  end
end

Instance Method Details

#go(*args) ⇒ Object 



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# File 'lib/rbkb/cli/rstrings.rb', line 77

def go(*args)
  super(*args)

  start_off = @opts[:start_off]
  end_off   = @opts[:end_off]
  enc  = @opts[:encoding]
  min  = @opts[:minimum]
  align = @opts[:align]

  @opts[:pr_fnames]=true if @opts[:fnames].size > 1

  i=0
  while buf=@opts[:indat].shift
    buf[start_off..end_off].strings(
      :encoding => enc,
      :minimum => min,
      :align => align
    ) do |off, len, type, str|
      if @opts[:pr_fnames]
        @stdout << "#{@opts[:fnames][i]}:"
      end
      @stdout << "#{(off+start_off).to_hex.rjust(8,"0")}:"+
                 "#{(len+start_off).to_hex.rjust(8,"0")}:"+
                 "#{type.to_s[0,1]}:#{str.delete("\000").inspect}\n"
    end
    i+=1
  end

  self.exit(0)
end

#make_parser ⇒ Object 



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# File 'lib/rbkb/cli/rstrings.rb', line 24

def make_parser()
  arg = super()
  arg.banner += " <file ... || blank for stdin>"

  arg.on("-s", "--start=OFFSET", "Start at offset") do |s|
    unless m=/^(?:(\d+)|0x([A-Fa-f0-9]+))$/.match(s)
      bail "invalid offset '#{s}'"
    end
    @opts[:start_off] = (m[2])? m[0].hex : m[0].to_i
  end

  arg.on("-e", "--end=OFFSET", "End at offset") do |e|
    unless m=/^(?:(\d+)|0x([A-Fa-f0-9]+))$/.match(e)
      bail "invalid offset '#{e}'"
    end
    @opts[:end_off] = (m[2])? m[0].hex : m[0].to_i
  end

  arg.on("-t", "--encoding-type=TYPE", 
    "Encoding: ascii/unicode/both (default=#{@opts[:encoding]})") do |t|
      @opts[:encoding] = t.to_sym
  end

  arg.on("-l", "--min-length=NUM", Numeric,
    "Minimum length of strings (default=#{@opts[:minimum]})") do |l|
      @opts[:minimum] = l
  end

  arg.on("-a", "--align=ALIGNMENT", Numeric, 
    "Match only on alignment (default=none)") do |a|
      (@opts[:align] = a) > 0 or bail "bad alignment '#{a}'"
  end

  return arg
end

#parse(*args) ⇒ Object 



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# File 'lib/rbkb/cli/rstrings.rb', line 60

def parse(*args)
  super(*args)
  if @opts[:indat].empty? and not @argv.empty?
    while a=@argv.shift
      @opts[:indat] << do_file_read(a)
      @opts[:fnames] << a
    end
  end

  parse_catchall()

  if @opts[:indat].empty?
    @opts[:indat] << @stdin.read() if @opts[:indat].empty?
    @opts[:fnames] << "[STDIN]"
  end
end