27 replies to this topic

[JanitorMoe]

I can't figure out how to change the color of text in C. I have googled and such but not really any explanations.

[mebob]

You need OS specific functions. If you are using Windows, you need to use functions such as WriteConsole(). To read up on the functions for Windows, go here.

[Ancient Dragon]

What operating system? If MS-Windows you will want to use the Windows Console Functions, specifically WriteConsoleOutputAttribute

Hereis a nice tutorial that shows you how to change the color of the text.

[mebob]

If you are using Windows, this program will display "Hello World!" in bright pink:

#include <windows.h>


int main()

{

	char msg[13] = "Hello World!";

		//Message to be written

	DWORD CharsWritten;

		//An output value of the function used to write to the console

	HANDLE conout;		//An identifier for the console window's text

	conout = CreateFile("CONOUT$",GENERIC_WRITE,0,NULL,3,FILE_ATTRIBUTE_NORMAL,NULL);

		//Sets the identifier to point to the console's window. CreateFile is Windows's function

		//for opening or creating a file

	SetConsoleTextAttribute(conout,FOREGROUND_BLUE|FOREGROUND_RED|FOREGROUND_INTENSITY);

		//Sets the color to a bright magenta

	WriteConsole(conout,msg,12,&CharsWritten,NULL);

		//Writes the message to the console

}

[JanitorMoe]

Yeah its windows, thanks for the links I will definitely read up. Is it possible for doing such a thing in Linux?

[Alexander]

Easily through ANSI terminal escapes, Dargueta has a nice tutorial here:
http://forum.codecal...ell-script.html

[mebob]

For Linux, although I do not know much on the matter, I think you would probably want to use something like ncurses.

EDIT: Or those escape sequences

[AdvMutant]

I'm not sure how helpful I am, but it's easy using TurboC(Windows). Just include conio.h, and use the following functions -

Quote

textcolor(int newcolor)

Quote

textbackground(int newcolor)

You can either provide numbers, or use the pre-defined color constants -

Quote

BLACK (0)
BLUE (1)
GREEN (2)
CYAN (3)
RED (4)
MAGENTA (5)
BROWN (6)
LIGHTGRAY (7)
DARKGRAY (8)
LIGHTBLUE (9)
LIGHTGREEN (10)
LIGHTCYAN (11)
LIGHTRED (12)
LIGHTMAGENTA (13)
YELLOW (14)
WHITE (15)

You can use all colors with textcolor(), but only the black ones with textbackground().

After you used the above functions and set your desired colors, nothing will change if you'll use the standard(puts, putch, printf) output functions. You'll have to use the following functions -

Quote

cprintf();
cputs();

They work the same as puts/printf, but are effected by the colors you set earlier. Here's a small example so you'll see what I'm talking about -

Quote

#include <stdio.h>
#include <conio.h>

int main()
{
clrscr();//Clears the screen.

textcolor(RED);//Makes the text red.
textbackground(BLUE);//Makes the text's background blue.
puts("This is a string");//Not effected.
cputs("This is another string");//The text will be red with blue background.

getch();//Pauses the program till a character is pressed.
return 0;
}

[mebob]

It's probably best to use the Windows API, because the old functions for DOS are slower. You can use the same color codes, so that won't be a problem.

EDIT: Removed the false information. Sorry!

Edited by mebob, 05 November 2010 - 08:15 PM.

[Alexander]

mebob said:

It's probably best to use the Windows API, because the old functions for DOS are much slower, and probably won't be supported in Windows forever. You can use the same color codes, so that won't be a problem.

They work directly with video modes IIRC, there is nothing to really discontinue.

[DarkLordofthePenguins]

Use the escape sequence \e

ex:
\e[31m makes the text red.
\e[32m makes the text green.
\e[3xm makes the text some other color.
\e[0m stops coloring text.

printf( "\e[31mHello World\e[0m\n" ); prints "Hello world" in red.

[Alexander]

DarkLordofthePenguins said:

Use the escape sequence \e

There is only \e in BASH, not in ANSI C. You must use \033 or equivalent.