conio.h doesn't contain textcolor()?

Question

I've been looking at using colours in a DOS program I'm writing in C. I was told that conio.h has the textcolor() function, but when I use it in my code, the compiler/linker throws errors at me saying I've an undefined reference to the function.

Does conio.h actually have this function or have I been told bull?

Answer 1

No, the conio.h library does not have the textcolor function defined. One of the ways that that function could be defined is the following (include the windows.h library):

void textcolor (int color)
{
    static int __BACKGROUND;

    HANDLE h = GetStdHandle ( STD_OUTPUT_HANDLE );
    CONSOLE_SCREEN_BUFFER_INFO csbiInfo;


    GetConsoleScreenBufferInfo(h, &csbiInfo);

    SetConsoleTextAttribute (GetStdHandle (STD_OUTPUT_HANDLE),
                             color + (__BACKGROUND << 4));
}

Answer 2

It's a Turbo C/C++ Compiler function. It is in the conio.h header, but only if you're using a Turbo C/C++ Compiler.

See page 384 of the Turbo C/C++ Compiler 2.0 docs, which says:

Function Selects new character color in text mode.

Syntax

#include <conio.h>
void textcolor(int newcolor); 

Prototype in conio.h

Remarks: textcolor selects the foreground character color. The foreground color of all characters subsequently written by the console output functions will be the color given by newcolor. You can give the color using a symbolic constant defined in conio.h. If you use these constants, you must include conio.h.

This function does not affect any characters currently on the screen, but only those displayed using direct console output (such as cprintf) after textcolor has been called.

[...]

See also: Colorizing text in Turbo C++.

Answer 3

Check the textcolor library library, it may do just what you need.

An example, showing how to use it:

#include<stdio.h>
#include<conio.h>
main()
{
   textcolor(RED);
   cprintf("C programming");

   getch();
   return 0;
}