; Filename: Strings-64.nasm
; Author:  Vivek Ramachandran
; Website:  http://securitytube.net
; Training: http://securitytube-training.com 
;
;
; Purpose: String Operations in 64-bit CPU

global _start			

section .text
_start:

	; scasb/w/d/q 
	; Compare memory to register 

	cld
	mov rax, 0x1234567890abcdef
	lea rdi, [var1]
	scasq

	lea rdi, [var2]
	scasq


	; cmpsb/w/d/q
	; Compare memory to memory

	cld
	lea rsi, [var1]
	lea rdi, [var3]
	cmpsq
	
		
	; exit the program gracefully  

	mov rax, 0x3c
	mov rdi, 0		
	syscall


section .data

	var1:	dq	0x1234567890abcdef
	var2:	dq	0xfedcba1234567890
	var3:	dq	0x1234567890abcdef