share/common/quvi/hex.lua

   1 -- libquvi-scripts
   2 -- Copyright (C) 2013  Toni Gundogdu <legatvs@gmail.com>
   3 --
   4 -- This file is part of libquvi-scripts <http://quvi.sourceforge.net/>.
   5 --
   6 -- This program is free software: you can redistribute it and/or
   7 -- modify it under the terms of the GNU Affero General Public
   8 -- License as published by the Free Software Foundation, either
   9 -- version 3 of the License, or (at your option) any later version.
  10 --
  11 -- This program is distributed in the hope that it will be useful,
  12 -- but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 -- GNU Affero General Public License for more details.
  15 --
  16 -- You should have received a copy of the GNU Affero General
  17 -- Public License along with this program.  If not, see
  18 -- <http://www.gnu.org/licenses/>.
  19 --
  20
  21 local M = {}
  22
  23 -- Returns an array of the numerical codes of the hexadecimal string.
  24 function M.to_arr(s)
  25   if not (#s % 2 ==0) then
  26     error(string.format('%s: invalid hexstring', s))
  27   end
  28   local B = require 'bit'
  29   local r = {}
  30   s:gsub('%x%x', function(n)
  31       table.insert(r, B.tobit(tonumber(n,16)))
  32     end)
  33   return r
  34 end
  35
  36 -- Returns an array of the internal numerical codes of the characters.
  37 function M.to_bytes(s)
  38   local r = {}
  39   s:gsub('.', function(c)
  40       table.insert(r, c:byte(1))
  41     end)
  42   return r
  43 end
  44
  45 -- Returns a hexadecimal string created from the array of the internal
  46 -- numberical codes of the characters.
  47 function M.from_bytes(b)
  48   local B = require 'bit'
  49   local r = {}
  50   for _,v in pairs(b) do
  51     table.insert(r, B.tohex(v,2))
  52   end
  53   return table.concat(r,'')
  54 end
  55
  56 -- Data to a hexadecimal string.
  57 function M.to_hex(s)
  58   local t = type(s)
  59   if t == 'string' then
  60     return M.from_bytes(M.to_bytes(s))
  61   elseif t == 'table' then
  62     return M.from_bytes(s)
  63   else
  64     error(string.format('invalid type: %s', t))
  65   end
  66 end
  67
  68 -- Returns a string of the internal numerical codes created from
  69 -- the hexadecimal string or the array of numerical codes of the
  70 -- hexadecimal string.
  71 function M.to_str(s)
  72   local a,t = type(s)
  73   if type(s) == 'string' then
  74     a = M.to_arr(s)
  75   elseif type(s) == 'table' then
  76     a = s
  77   else
  78     error(string.format('invalid type: %s', t))
  79   end
  80   local r = {}
  81   for _,v in pairs(a) do
  82     table.insert(r, string.char(v))
  83   end
  84   return table.concat(r,'')
  85 end
  86
  87 --[[
  88 --
  89 -- tests
  90 --
  91
  92 function test_eq(t,r,e)
  93   if not (r == e) then error(string.format('%s: failed', t)) end
  94 end
  95
  96 -- to_hex(string)
  97 test_eq('test/to_hex #1', M.to_hex({0x0b,0x02,0x04,0x08,0xa}), '0b0204080a')
  98 test_eq('test/to_hex #2', M.to_hex('foo'), '666f6f')
  99
 100 -- to_str
 101 test_eq('test/to_str #1', M.to_str({0x66,0x6f,0x6f}), 'foo')
 102 test_eq('test/to_str #2', M.to_str('666f6f'), 'foo')
 103 ]]--
 104
 105 return M
 106
 107 -- vim: set ts=2 sw=2 tw=72 expandtab: