feat(strcpy): adding my own strcpy version

src/ft_strcpy.s

@@ -0,0 +1,23 @@
+segment .note.GNU-stack
+
+section .text
+	global ft_strcpy
+
+ft_strcpy:
+	mov	rax, rdi					; dest is the return value
+	cmp rdi, 0						; check if dest is NULL
+	je .exit						; if true return NULL
+	cmp rsi, 0						; check if dest is NULL
+	je .exit						; if true return NULL
+	xor ecx, ecx					; index set to 0
+
+.loop:
+	mov dl, BYTE [rsi + rcx]		; take the value of src
+	mov BYTE [rax + rcx], dl		; copy the value of src in dst
+	cmp dl, 0						; check if the null byte is the last copied
+	je .exit						; return if it was the last byte
+	inc rcx							; increment the index
+	jmp .loop						; restart the loop again
+
+.exit:
+	ret								; return the rax (dest) value