#!/usr/bin/lua 
--[===[ 
#(c) 2010 Adam Pridgen adam@praetoriangrp.com, adam.pridgen@thecoverofnight.com
# hexlify.lua:
# 		Provides a LUA command script to perform hexlification and unhexlification
#
#
# GPLv3 License
# 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 3 of the License, or
# 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, see <http://www.gnu.org/licenses/>.
]===]
local todo = arg[1]
local infile = arg[2]
local outfile = arg[3]

if (todo == nil or infile == nil or outfile == nil) then
	print ("usage:\n" .. arg[0] .. " [-u] [-h] infile outfile\n")
	os.exit(-1)
end

if (todo == "-h") then
	print ("Performing hexlify\n")
	local f = io.open(infile, 'rb')
	local bytes = f:read('*all')
	f:close()
	local g = io.open(outfile, 'w')
	for b in string.gfind(bytes, ".") do
		g:write(string.format('%02X', string.byte(b)))
	end
	g:close()
elseif (todo == "-u") then
	print ("Performing unhexlify\n")
	local f = io.open(infile, 'r')
	local bytes = f:read('*all')
	f:close()
	local g = io.open(outfile, 'wb')
	for b in string.gfind(bytes, "..") do
		g:write(string.char(tonumber(b,16)))
	end
	g:close()
else 
	print ("Bad todo string:\nusage:" .. arg[0] .. " [-u] [-h] infile outfile\n")
	os.exit(-1)
end
print('Done reading ' .. infile .. ' and ' .. outfile .. ' was written!\n')
os.exit(0)