#!/usr/bin/env ruby
# $Id: iso2.rb,v 1.7 2006/12/16 03:44:48 rocky Exp $
# A program to show using iso9660 to extract a file
# from an ISO-9660 image.
#
# If a single argument is given, it is used as the ISO 9660 image to
# use in the extraction. Otherwise a compiled in default ISO 9660
# image name (that comes with the libcdio distribution) will be used.

#  Copyright (C) 2006 Rocky Bernstein <rocky@gnu.org>
#  
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#  
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#  
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

mypath = File.dirname(__FILE__)
if(File::exists?(mypath + "/../lib/cdio.rb"))
  $: << File.dirname(__FILE__) + '/../lib'
  $: << File.dirname(__FILE__) + '/../ext/cdio'
  $: << File.dirname(__FILE__) + '/../ext/iso9660'
else
  require 'rubygems'
  require_gem "rbcdio"
end

require "iso9660"

# The default CD image if none given
cd_image_path = "../data"
cd_image_fname = cd_image_path +  "/isofs-m1.cue"

# File to extract if none given.
iso9660_path="/"
local_filename="COPYING"

if ARGV.length() > 1
    cd_image_fname = ARGV[0]
    if ARGV.length() > 2
        local_filename = ARGV[1]
        if ARGV.length() > 3
            puts "\nusage: %s [CD-ROM-or-image [filename]]\nExtracts filename from CD-ROM-or-image." % $0
            exit(1)
        end
    end
end

begin 
    cd = ISO9660::FS::new(cd_image_fname)
rescue
    puts "Sorry, couldn't open %s as a CD image." % cd_image_fname
    exit(1)
end

statbuf = cd.stat(local_filename, false)

if not statbuf
    puts "Could not get ISO-9660 file information for file %s in %s" % 
    [local_filename, cd_image_name]
    cd.close()
    exit(2)
end

o = open(local_filename, "w", 0664)
if not o
    puts "Can't open %s for writing" % local_filename
end

# Copy the blocks from the ISO-9660 filesystem to the local filesystem. 
blocks = (statbuf['size'].to_f / Rubycdio::ISO_BLOCKSIZE).ceil()
for i in 0 .. blocks - 1
    lsn = statbuf['lsn'] + i
    size, buf = cd.read_data_blocks(lsn)

    if size < 0
        puts "Error reading ISO 9660 file %s at LSN %d" % [
            local_filename, lsn]
        exit(4)
    end
    
    o.write(buf)
end

o.close()

# Make sure the file size has the exact same byte size. Without the
# truncate below, the file will a multiple of ISO_BLOCKSIZE.

f = File.new(local_filename, "r+")
f.truncate(statbuf['size'])
f.close()

puts "Extraction of file '%s' from %s successful." % [
    local_filename,  cd_image_fname]

cd.close()
exit(0)