Have just started teaching myself C and thought the following may be useful to fellow strugglers!
They use inline asm to print messages and also clear the screen in one line with system("cls")
There are no header files needed ie no <stdio.h> stuff
/* test01.c Shows using _asm to print message ( See Test02.c for arrays */
main()
{
char *namer = "Hello, world pointers! $";
system("cls"); //Clear Screen
_asm
{
mov dx, namer ; ";" is for comments
mov ah,09h
int 21h ;A DOS interrupt
}
}
/* test02.c Access contents of an array using _asm */
main()
{
char name[20] = "Hello, double pointers! $";
char *dummy = name;
/* So dummy contains the address of pointer */
_asm
{
mov dx, byte ptr dummy
;The above is tricky - it moves the address
;of dummy into dx for the DOS interrupt
mov ah,09h
int 21h
}
}
THE FOLLOWING DOES NOT WORK
/* DOES NOT WORK ( See Test 01 & Test02 for ones that work ) */
main()
{
char name[30] = "Hello, world fails! $";
_asm
{
mov dx, name
mov ah,09h
int 21h
}
}
I think it fails because although "name" is the pointer to name[30] it is a kind of hybrid as far as asm is concerned ( or something ) If you run this program you will find it ploughs through huge amounts of memory and finally prints garbage ending with Hello, world fails! So it sort of works ...
