Conio.h in C

Header files are the source files with the extension of .h. In c language header files are referred to as the helping files and they contain definitions of various functions and macro definitions to be shared between various source files. Header files are used in the program with the C preprocessor directive i.e “#include”.

Here are some of the header files in C language.

#include<stdio.h>

#include<conio.h>

#include<string.h>

#include<iostream.h>

#include<iomanip.h>

Conio.h

Conio. h is an abbreviation for console input/output header file, which manages input/output on the console, here console is the screen where output is displayed.

MS-DOC compilersuse it mostly for console input/output.C standard library or ISO C does not contain this header file, also not defined by POSIX.

This conio.h header file declares many useful functions such as shown below. The header file in our program is to be included to use the following functions.In conio.h the declared library functions vary from compiler to compiler

• kbhit();
• textColor();
• textbackground();
• clrscr();
• getch();
• getche();
• gotoxy();
• wherex();
• wherey();

There are mainly two functions i.e getch() and clrscr() which are used with the conio.h apart from these many other functions are also used.

getch();(get a character)

This function is nonstandard.From the keyboard,it reads a single character and doesnot print it on console. It is alsoused to hold the output window until any key is pressed. It is without echo that means does not print on screen.

Example:

#include <stdio.h>
#include <conio.h> //header file
void main()
{
Printf(“hold the screen”);
getch();  //getch function
}

Output

hold the screen

clrscr();   (clear screen)

To clear the previous output in the console window this function is used. The output window will become messy if we won’t use this function.

Example:

#include <stdio.h>
#include <conio.h>
void main()
{
		clrscr();//clrscr function
Printf(“hello javatpoint with clear console”);
getch();
}

Output

hello javatpoint with clear console

kbhit();    (keyboard hit)

This functionis used to check whether a key is pressed or not. It returnsa zero value when a key is not pressed and returnsa non-zero value when a key is pressed. It should be avoided.

Example:

#include <stdio.h>
#include <conio.h>
int main()
{
do {
printf("stop loop by entering any key");
} 
while (!kbhit());//getch function
return 0;
}

Output

stop loop by entering any key
stop loop by entering any key
stop loop by entering any key
stop loop by entering any key
stop loop by entering any key
Till N time, until you don't press any key.

textcolor();

The color of the text can be changed by using this textcolor( ) function. It is mostly not supported.Here we directly color the name or integer value from 0 to 15. Use the colors in the upper case.

BLACK0

BLUE1

GREEN2

CYAN 3

RED4

MAGENTA5

BROWN6

LIGHT GRAY7

DARK GRAY8

LIGHT BLUE 9

LIGHT GREEN10

LIGHT CYAN11

LIGHT RED12

LIGHT MAGENTA13

YELLOW 14

WHITE15

Example:

#include<stdio.h>
#include<conio.h>
Void Main(){
textcolor(RED);// textcolor function 
cprintf("C");
getch();
return 0
}

Output

C

Note: cprintf function is used in place of printf. Because the formatted output to the text window on the screen is sent by cprintf where printf sends it to stdin.

textbackground();

The background color in text mode can be changed by using this textbackground(). It is also not supported mostly. Use the color name in the upper case.

Example:

include<stdio.h>
#include<conio.h>
main()
{
textbackground(YELLOW); // textbackground function
cprintf("change background color");
getch();
return 0;
}

Output

change background color

getche();   (get character with echo)

From the keyboard, it takes the input and immediately it displays without waiting until enter key is pressed.It is with an echo which means itprintsa character on screen.

Example:

#include<stdio.h>
#include<conio.h>
void main()
{
char ch;
printf(“Press any character: ”);
ch = getche();// getche function
printf(“\nPressed character is: %c”, ch);
}

Output

Press any character: e
Pressed character is: e

wherex();

Used for getting cursor position. The co-ordinate of x is given by the wherex() function. Mainly used in game making.

Example:

#include <stdio.h>
#include <conio.h>
main()
{
int a;
printf("Includehelp\n\n");
a = wherex();// printing the position of cursor
printf("The cursor position on X-axis after message printing = %d\n",a);
getch();
return 0;
}

Output:

Includehelp
The cursor position on X-axis after message printing =1

The cursor position on X-axis after message printing =1

wherex();

Used for getting cursor position. The co-ordinate of y is given by the wherex() function. Mainly used in game making.

Example:

#include <stdio.h>
#include <conio.h>
main()
{
int a;
printf("Includehelp\n\n");
a = wherey();   // printing the position of cursor
printf("The cursor position on Y-axis after message printing = %d\n",a);
getch();
return 0;
}

Output:

Includehelp
The cursor position on Y-axis after message printing =1

Important Points

• In turbo C/C++ we find the conio.h header file that uses a 16-bit compiler. It is not used in the GCC compilers because, functions like getch(),clrscr() etc, are not available to use.
• In GCC compiler clear of the console is done automatically and no need to worry about getch() functions.