How does one convert an integer to a string using the Nasm preprocessor? For example, consider the following code:
%define myInt 65
%define myString 'Sixty-five is ', myInt
The symbol myString will evaluate to Sixty-five is A. The desired result is Sixty-five is 65. How can I achieve this? It seems like such a trivial question, but the Nasm documentation has yielded nothing. Thanks!
This code
%define myInt 65
%define quot "
%define stringify(x) quot %+ x %+ quot
%strcat myString 'Sixty-five is ', stringify(myInt)
bits 32
db myString
produces the following listing file:
1 %define myInt 65
2 %define quot "
3 %define stringify(x) quot %+ x %+ quot
4 %strcat myString 'Sixty-five is ', stringify(myInt)
5
6 bits 32
7 00000000 53697874792D666976- db myString
8 00000009 65206973203635
and the following binary:
0000000000: 53 69 78 74 79 2D 66 69 │ 76 65 20 69 73 20 36 35 Sixty-five is 65
I used NASM version 2.10 compiled on Mar 12 2012.
%defstrmovzx. I may have missed the option in the docs although I only saw -seg16.
#include <sys/80186.h> is the closest you can get right now.You should use %defstr macro.
%define myInt 65
%defstr strInt myInt
%define myString 'Sixty-five is ', strInt
https://www.nasm.us/xdoc/2.15.05/html/nasmdoc4.html#section-4.1.9
At the moment can't test this with NASM, but this works at least in YASM (I added a Linux x86-64 printing code to make testing easier):
[bits 64]
%define myInt 65
%define myTens myInt/10 + 48
%define myOnes myInt-(myInt/10)*10 + 48
%define myString 'Sixty-five is ', myTens, myOnes
section .text
global _start
_start:
mov edi,1 ; STDOUT
mov rsi,my_string
mov edx,my_string_length ; length of string in bytes.
mov eax,1 ; write
syscall
xor edi,edi
mov eax,60 ; exit
syscall
section .data
my_string db myString
db 0x0a
my_string_length equ $-my_string
