Ok, what I am trying to do is set a certain bit of a byte. I want to be able to set the 3rd most significant byte to 1. If the byte was 00000000, I want it to be 00100000. If it was 10001100, I would want to change it to 10101100. The way I am going about it should work, according to according to Joseph Farrels article here in bitwise operations. But it dosn''t. I am basically doing this: BYTE BitMask = 32; // is 00100000 binary BYTE MyByte = 22; // is 00010110 binary MyByte = MyByte | BitMask; // MyByte should now equal 00110110 binary. //but it dosn''t. This is probably extremely obvious. But I cannot figure it out. That article explained it very well, but it failed to give an example. This is all I could come up with, but it dosn''t work. And of course, this is a simplified version of my problem. What I am really trying to do is to convert an 8 char string containing 1''s and 0''s to an 8 bit variable. I could just create a huge lookup table, but this should work, and is a much easier way to do it. If I could get it to work. If it matters, I am programming in Borland C++ 5.02 with windows 98. If you could help, I would really appreciate it.

I really couldn''t tell. You see, in practice the variables are different all the time. This is just an example I have made up. When I fputc() the byte, it always winds up showing as an y with two dots on top of it. I am not sure what it is called, and I couldn''t find it on my ascii tables.

And cloxs, isn''t that basically what I am doing?

Thank you,invective. That is so much easier then what I was attempting. I am still open to suggestions as to what went wrong, however.

Ok, I rewrote all my code in a much more efficient manner. I am now having different problems, but they are related. I really cannot find out what is wrong with this:

  void TextToBin(void){   const BYTE BitMask[8] = {128,64,32,16,8,4,2,1};   char c;   int i;   while(c != EOF)   {      c = fgetc(fOriginal);      if(c == EOF)      	break;      // each loop converts 1 char to 8 chars      for(i = 0;i <= 7;i += 1)      {      	if(c & BitMask[i])         {         	fputc('1',fNew);         }         else         {         	fputc('0',fNew);         }      }   }}  

This is the routine I use for translating a file into binary. The input file on my test was a plain text file containing:

abcdefghijklmnopqrstuvwxyz(return)
ABCDEFGHIJKLMNOPQRSTUVWXYZ

I am sure this is working, because looking at the output and manually converting the first few bits it does seem ok. The first 8 chars are binary for an ascii 'a', the next 8 are binary for an ascii 'b', and so on.

  void BinToText(void){   char c,cr;   int i;   while(c != EOF)   {      // each loop reads 8 chars      for(i = 0;i <= 7;i += 1)      {      	c = fgetc(fOriginal);        cr = 0;         if(c == EOF)        	break;         if(c == '1')         {            cr = cr | 1; // 1 is decimal for 00000001            cr << 1;          }      }      fputc(cr,fNew);   }}  

This is what seems not to be working. I first ran the first function, then ran this one on the results of that. It should turn it back into readable text, but the result file is merely junk, namely:






Edited by - Gwahir the Windlord on November 5, 2001 1:41:44 PM

Make your BiteMask array a static global outside of your two functions. Then, replace your last lines with this:

    if (cr == '1')    cr |= BitMask[i];    

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Edited by - bishop_pass on November 5, 2001 1:49:40 PM