Lua小程序 十六进制字符串与二进制数据间的转换.doc

Lua小程序 十六进制字符串和二进制数据间的转换 从十六进制字符串转为二进制数： 1 #! /usr/local/bin/lua 2  3  4 --Note: Input hex string files content must be  5 --a upper case hex string  6  7 --Check the arguments 8 if #arg ~= 2 then 9 print(Usage:hexstr2bytes.lua Input Hex String File Output Bytes File\n);10 os.exit();11 end12 13 --Open input hex string file14 local hexstrfile = io.open(arg[1], rb);15 if nil == hexstrfile then16 print(Can not open input file!\n);17 os.exit();18 end19 20 --Read from the hex string file21 local hexstr = hexstrfile:read(*a);22 if nil == hexstr then23 print(Can not read hex string from input file!\n);24 elseif 1 == string.len(hexstr)%2 then25 print(Hex string size must be evel!\n);26 os.exit();27 else28 print(Hex String:, hexstr, \n);29 end30 31 --Close hex string file32 hexstrfile:close();33 34 --Open output binary file35 local bytesfile = io.open(arg[2], wb);36 if nil == bytesfile then37 print(Can not open output file to write!\n);38 os.exit();39 end40 41 --Convert hex string to bytes42 for i = 1, string.len(hexstr) - 1, 2 do43 local doublebytestr = string.sub(hexstr, i, i+1);44 local n = tonumber(doublebytestr, 16);45 if 0 == n then46 bytesfile:write(\00);47 else48 bytesfile:write(string.format(%c, n));49 end50 end51 52 --Close output binary file53 bytesfile:close();54 55 56 从二进制数转十六进制字符串： 1 #! /usr/local/bin/lua 2  3  4 --Check the arguments 5 if #arg ~= 2 then 6 print(Usage:bytes2hexstr.lua Input Bytes File Output Hex String File\n); 7 os.exit(); 8 end 9 10 --Open input bytes file11 local bytesfile = io.open(arg[1], rb);12 if nil == bytesfile then13 print(Can not open input file!\n);14 os.exit();15 end16 17 --Read from the bytes file18 local bytes = bytesfile:read(*a);19 if nil == bytes then20 print(Can not read bytes from input file!\n);21 os.exit();22 end23 24 --Close bytes file25 byte