Thread: SetConsoleTextAttribute

Could anybody help me to understand what the | OR bitwise operator doing in this function?

Code:

SetConsoleTextAttribute ( h, BACKGROUND_RED | 8 );

Here's the whole program btw.
http://cboard.cprogramming.com/showthread.php?t=110879

What is it that you do not understand about it?

--
Mats

It would be better to go read the manual to find out what 8 really means (bold, flash, whatever), and use the appropriately named readable constant.

Not some magic number pulled out of the ether.

You mean such as:
FOREGROUND_INTENSITY

--
Mats

Well i already checked out the manual but it says nothing about numbers or bitwise operator.

And what is it that a color has to do with a bitwise operator?

http://msdn.microsoft.com/en-us/libr...47(VS.85).aspx

Im really lame. Im gonna pay more attention next time. Thank you Tabstop!

But what about the number 8, what does it mean?

Originally Posted by Ducky

Im really lame. Im gonna pay more attention next time. Thank you Tabstop!

But what about the number 8, what does it mean?

My guess is that it's the foreground intensity bit [based on guess-and-vague-memory principle] that I posted about earlier, but if you have Visual Studio or some other editor that allows you to "go to definition" of that name, then go to the definition of the background colour, and the all declaration of the foreground and background colours are (I would expect) nearby, so just find which one has the value 8.

--
Mats

As stated by matsp:

Code:

#define FOREGROUND_INTENSITY 0x0008 // text color is intensified.

From: http://doc.ddart.net/msdn/header/include/wincon.h.html

You probably just shouldn't be using 8 in this context. But if you have 8, you can try to find the windows header where all these BACKGROUND_BLUE's and such are defined and see which of these is defined as 8.

In "wincon.h" you'll find the following:

Code:

#define FOREGROUND_BLUE	1
#define FOREGROUND_GREEN	2
#define FOREGROUND_RED	4
#define FOREGROUND_INTENSITY	8
#define BACKGROUND_BLUE	16
#define BACKGROUND_GREEN	32
#define BACKGROUND_RED	64
#define BACKGROUND_INTENSITY	128

Thank you, anon. You sure know how to recognize different types of trees from quite a long way away.

Wow that was simple! Now either these kind of things arent in the tutorials or i must have missed them somehow.

Anyways, thanks a lot everybody!

Also notice that all the constants are powers of two (in binary these are numbers which have one bit set - each value a different bit). This is what allows them to be combined using bitwise or (in case you want to do something like this yourself)