#!/usr/bin/ruby 

# Copyright 2010, Geir Isene. Released under the GPL v. 2
# Version 0.1 (2010-03-08)

def help
puts <<HELPTEXT

NAME
        lifasread - LIF ascii file read

SYNOPSIS
	lifasread [-hv] [--help, --version] [lif-file] [destination file]

DESCRIPTION
	lifasread is used as a tool for HP-41 or HP-71 connected to a PC.
	lifasread reads an ascii file inside a lif formated file.
	It reads only the first ascii file and so the lif-file should
	be consisting of only one file. To create a lif file with only
	one file from an HP-41, have your calculator hooked to the PC
	and/or a lif-writing mass storage device and XEQ "NEWM 001". Then
	put the size of the ascii file in the X register and its name in
	the Alpha register. Then XEQ "CRFLAS". Fill it with content as needed,
	and XEQ "SAVEAS" to save the file to mass storage.
	Then from your PC execute lifasread to extract the content.
	The sister-script "lifaswrite" will reverse the process.

OPTIONS
        -h, --help
                Show this help text
    
        -v, --version
                Show the version of imap_search

EXAMPLE
	lifasread hdrive1.lif textfile.txt

	This would extract the ascii file from "hdrive1.lif" and write
	it to the file "textfile.txt".
    
COPYRIGHT:
        Copyright 2010, Geir Isene (http://www.geir.isene.com, g@isene.com)
        This program is released under the GNU General Public lisence v3
        For the full lisence text see: http://www.gnu.org/copyleft/gpl.html

HELPTEXT
end

require 'getoptlong'

opts = GetoptLong.new(
    [ "--help",             "-h",   GetoptLong::NO_ARGUMENT ],
    [ "--version",          "-v",   GetoptLong::NO_ARGUMENT ]
)

version = "0.1"

opts.each do |opt, arg|
  case opt
    when "--help"
      help
      exit
    when "--version"
      puts "\nlifasread version " + version + "\n\n"
      exit
  end
end

if ARGV.empty? then 
  puts "No arguments supplied!"
  exit 
end

if ARGV.length < 2 
  puts "Too few arguments supplied!"
  exit 
end

lif_file = ARGV[0]
txt_file = ARGV[1]

# Get lif-file from HDRIVE1
f = File.open(lif_file, 'r') {|f| f.read }

# Strip the front and back of the file and collect the ascii file name
fname = f.sub(/^.*?(\w+).*$/,'\1')
fcont = f.sub(/^.*REMF.*?\000[\014-\376](\w.*?)\000\377.*$/,'\1')
fcont = fcont.gsub(/\000[\014-\376]/,"\n")
fcont = fcont.gsub(/\000/,'')
lif_total = fname + "\n\n" + fcont

# Save it to text file
File.open(txt_file, 'w') {|f| f.write(lif_total) }

# Tell the user to complete the synchronization by pressing R/S on his 41
puts "\"#{lif_file}\" extracted to \"#{txt_file}\""