_graphgetmem & _graphfreemem examples in c

Header file:
    graphics.h

Synopsis:
      void far * far _graphgetmem(unsigned size);
     void far _graphfreemem(void far *ptr, unsigned size);
    
Description:
     User hooks which can be used for memory allocation and deallocation.

_graphgetmem & graphfreemem functions in c graphics

  #include <graphics.h>
  #include <stdlib.h>
  #include <stdio.h>
  #include <conio.h>
  #include <alloc.h>

  /* called by the graphics kernel to allocate memory */
  void far * far _graphgetmem(unsigned sz) {
        printf("Inside _graphgetmem to allocate %d bytes\n", sz);
        delay(500);
        /* allocate memory from far heap */
        return farmalloc(size);
  }

  /* called by the graphics kernel to free memory */
  void far _graphfreemem(void far *ptr, unsigned sz) {
        printf("Inside _graphfreemem to deallocate %d bytes\n", sz);
        delay(500);
        /* free ptr from far heap */
        farfree(ptr);
  }

  int main(void) {
        /* request auto detection */
        int graphicDriver = DETECT;
        int graphicMode, err;

        /* initialize graphics and local variables */
        initgraph(&graphicDriver, &graphicMode,
                                        "C:/TURBOC3/BGI");

        /* read result of initialization */
        err = graphresult();

        if (err != grOk) {
                /* an error occurred */
                printf("Graphic Error: %s\n",
                                grapherrormsg(err));
                getch();
                return 0;
        }

        /* display a message */
        settextjustify(CENTER_TEXT, CENTER_TEXT);
        outtextxy(getmaxx() / 2, getmaxy() / 2, "Closing graphics");

        /* clean up */
        closegraph();
        return 0;
  }