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Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?)

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On 10/16/11 11:39 AM, Martin Jørgensen wrote:
> On Oct 15, 11:35 pm, Richard Damon<news.x.richardda...@xoxy.net>
> wrote:
>> On 10/15/11 3:00 PM, someone wrote:
> ==
>>> I'm stuck...
>>
>>> And what about big endian / little endian? I'm confused. Looking
>>> forward to hear from you!
>>
>> First, what is the first byte in the file? you are saying that you are
>> expecting it to be 72 but you are getting 49. Have you looked at the file..
>
> Good point. The first four bytes of the input file has the values:
> [048h 00h 00h 00h] (hexadecimal, I used a hex editor to see this). And
> 0x48H = 72 decimal... I don't even know if this is little endian or
> not, but what I find very strange is the number 49 then... That number
> makes no sense to me (why is it adding 1, if it's printing the number
> in hexadecimal? What's it thinking?)..?

If you are in a 32 bit little endian (x86) machine, this will work:

#include <iostream>

int main()
{
   char tmp[4] = {0x48,0,0,0};

   std::cout << *reinterpret_cast<int*>(tmp) << std::endl;

   return 0;
}

If not, you will have to build the integer value from the individual 
bytes.  For example if the data were written on a big endian machine:

   char be[4] = {0,0,0,0x48};

   int n = be[3] + (be[2]<<8) + (be[1]<<16) + (be[0]<<24);

   std::cout << n << std::endl;

-- 
Ian Collins

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reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-15 12:00 -0700
  Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Ian Collins <ian-news@hotmail.com> - 2011-10-16 09:29 +1300
    Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-15 14:17 -0700
      Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Ebenezer <woodbrian77@gmail.com> - 2011-10-15 14:41 -0700
      Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Ian Collins <ian-news@hotmail.com> - 2011-10-16 10:45 +1300
        Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Martin Jørgensen <mjoerg@gmail.com> - 2011-10-15 15:43 -0700
          Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-15 21:37 -0400
            Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-15 23:23 -0700
              Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Ian Collins <ian-news@hotmail.com> - 2011-10-16 20:53 +1300
                Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Paavo Helde <myfirstname@osa.pri.ee> - 2011-10-16 03:04 -0500
                Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Ian Collins <ian-news@hotmail.com> - 2011-10-16 21:52 +1300
            Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-10-16 18:21 +0000
              Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-16 16:40 -0400
                Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Ian Collins <ian-news@hotmail.com> - 2011-10-17 10:00 +1300
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 15:19 -0700
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-16 20:03 -0400
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 17:49 -0700
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-16 21:29 -0400
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-10-17 09:10 +0000
  Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-15 17:35 -0400
    Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Martin Jørgensen <mjoerg@gmail.com> - 2011-10-15 15:39 -0700
      Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-15 16:12 -0700
        Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-15 16:32 -0700
          Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-15 19:41 -0400
            Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 11:33 -0700
              Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Paavo Helde <myfirstname@osa.pri.ee> - 2011-10-16 13:54 -0500
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Paavo Helde <myfirstname@osa.pri.ee> - 2011-10-16 14:01 -0500
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 15:12 -0700
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-16 20:14 -0400
                Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 17:56 -0700
      Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Ian Collins <ian-news@hotmail.com> - 2011-10-16 12:33 +1300
        Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-15 16:37 -0700
        Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Leigh Johnston <leigh@i42.co.uk> - 2011-10-16 19:59 +0100
          Re: reading binary file into memory. Converting from char to uint32,   float, double, ASCII strings etc (static_cast< > ?) Leigh Johnston <leigh@i42.co.uk> - 2011-10-16 20:13 +0100
            Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Joshua Maurice <joshuamaurice@gmail.com> - 2011-10-17 18:17 -0700
              Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Joshua Maurice <joshuamaurice@gmail.com> - 2011-10-17 18:32 -0700
  Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Pavel <pauldontspamtolk@removeyourself.dontspam.yahoo> - 2011-10-15 19:56 -0400
    Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-15 23:27 -0700
      Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Paavo Helde <myfirstname@osa.pri.ee> - 2011-10-16 02:48 -0500
        Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 10:57 -0700
          Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Paavo Helde <myfirstname@osa.pri.ee> - 2011-10-16 13:18 -0500
            Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 12:52 -0700
  Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 10:58 -0700
    Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Paavo Helde <myfirstname@osa.pri.ee> - 2011-10-16 13:37 -0500
      Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) someone <newsboost@gmail.com> - 2011-10-16 14:37 -0700
        Re: reading binary file into memory. Converting from char to uint32, float, double, ASCII strings etc (static_cast< > ?) Paavo Helde <myfirstname@osa.pri.ee> - 2011-10-17 01:21 -0500

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