Thread: write to hex, is it possible?

Please let me know if this is possible or even remotely possible! I need to write to a file, but directly to hex. For example, if I write "2D" to the file, i want to be able to open the file in a hex editor and see "2D" in the hex portion, not the ASCII portion. the only way i have been able to get "2D" into the hex portion is by writing "-" to the file.

i have been told this is possible, but so far have come up empty-handed. any ideas, hints, code, or suggestions would be greatly appreciated! Thanks!

keith

awesome, that worked! thanks much.

followup question, though - this just converts a char. what if i had, say something that looked like this that needed converting:

100000000100020080BB000000EE0200

is there a more convenient way than just doing it character by character?

please let me know, and thanks so much for the help!

keith

ok, this isn't working for me. i get an error when i compile. perhaps you could look at my code and see what i am doing wrong (something stupid, probably). here is a copy of the error for the following code:
--------------------------------------------------------------------------------
error C2664: 'write' : cannot convert parameter 1 from 'char (*)[100]' to 'const char *'
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
--------------------------------------------------------------------------------
and here is the code:


main() {
char blah[100];
string userfilename;
string useroutput;
cout <<"type in output filename." <<endl;
cin >> useroutput;

std::ofstream fout;
blah[100] = 0x2D;
fout.open(useroutput.c_str(), std::ios::binary);
fout.write(&blah,100);

return 0;

}

Code:

main() {
   char blah[100];
   string userfilename;
   string useroutput;
   cout <<"type in output filename." <<endl;
   cin >> useroutput;

   std::ofstream fout;
   blah[100] = 0x2D;
   fout.open(useroutput.c_str(), std::ios::binary);
   fout.write(blah,100);
   return 0;
}

Remove the & from the write function. blah is already a pointer. Actually is a const pointer.

ok. ALMOST there!

when i compile this, i get gibberish for everything except for a 2D wherever i put 0x2D in the array. this is correct, but if i put anything longer than 2D, like

0x2D003EE0

it gives me an error...understandable. is there anyway to stick 0x2D003EE0---------- into more than one slot in the array? because by the looks of it, right now i still have to write out each char, i.e. blah[0] = , blah[1] = , and so on and so forth....

any ideas? thanks so much.

Most excellent!

Thanks SO much for all your help, this worked, and i think that's it for now.



keith

Say I have something like the following:

int total_after_data = x - 44;

is there anyway to make total_after_data convertible to hex, and printable like the following?

*(long*)ib = 0x46464952;
fout.write(ib,4);

where "total_after_data_converted" would replace '46464952'?


thanks,
keith.

p.s. - if this is too ambiguous i can describe in fuller detail. thanks.