Textwidth function returns the width of a string in pixels.
Declaration: int textwidth(char *string);
C programming source code for textwidth
#include <stdio.h>
#include <graphics.h>
#include <conio.h>
#include <graphics.h>
#include <conio.h>
int main()
{
int gd = DETECT, gm, width;
char array[100];
initgraph(&gd, &gm, "C:\\TC\\BGI");
width = textwidth("C programming");
sprintf(array,"Textwidth = %d",width);
outtext(array);
getch();
closegraph();
return 0;
}