#!/usr/bin/env ruby
#
# rstrings is "strings"... in ruby... with extra stuff
#
# Usage: rstrings [options] <file | blank for stdin>
#   -h, --help                       Show this message
#   -v, --version                    Show version and exit
#   -s, --start=OFFSET               Start at offset
#   -e, --end=OFFSET                 End at offset
#   -t, --encoding-type=TYPE         Encoding: ascii|unicode|both (default=both)
#   -l, --min-length=NUM             Minimum length of strings (default=6)
#   -a, --align=ALIGNMENT            Match only on alignment (default=none)
# 

require 'rbkb'
require 'rbkb/command_line'

include RBkB::CommandLine

#-------------------------------------------------------------------------------
# Init options and arg parsing
OPTS = {
  :start_off => 0, 
  :end_off => -1, 
  :encoding => :both, 
  :minimum => 6,
  :align => nil,
  :indat => Array.new,
  :fnames => Array.new,
}

arg = bkb_stdargs(nil, OPTS)

arg.banner += " <file | blank for stdin>"

#------------------------------------------------------------------------------
# Add local options

arg.on("-s", "--start=OFFSET", "Start at offset") do |s|
  unless m=/^(?:(\d+)|0x([A-Fa-f0-9]+))$/.match(s)
    raise "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)
    raise "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 raise "bad alignment '#{a}'"
end


#------------------------------------------------------------------------------
# Parse arguments
arg.parse!(ARGV) rescue bail "Error: #{$!}\n#{arg}"

# default string arg
if OPTS[:indat].empty? and not ARGV.empty?
  while a=ARGV.shift
    OPTS[:indat] << File.read(a) rescue(bail "Error: Can't open '#{a}'")
    OPTS[:fnames] << a
  end
end

# catchall
if ARGV.length != 0 
  bail "Error: bad arguments - #{ARGV.join(' ')}\n#{arg}"
end

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

#------------------------------------------------------------------------------
# Do stuff

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

begin
  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]
        print "#{OPTS[:fnames][i]}:"
      end
      puts "#{(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}"
    end
    i+=1
  end
rescue
#  STDERR.puts $!
#  exit 1
end