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assemblypreprocessornasm

Nasm: Convert integer to string using preprocessor

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!

Solution

  • 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.