NasmLessons/03-printf.asm

;;; Required packages: nasm, gcc, gcc-multilib
;;; Compile commands:
;;;     nasm -f elf 03-printf.asm -o bin/03-printf.o
;;;     gcc -m32 -o bin/03-printf.out bin/03-printf.o
;;;
section .data
    message_fmt db "Value %d, address %d", 0xa, 0 ; 0 - end of string, required by printf func
    variable dd 120 ; 4 byte

section .text 
    extern printf
    global main

main:
    ; output
    push variable ; get memory address
    push DWORD [variable] ; get value by memory address
    push message_fmt 
    call printf
    add esp, 12 ; sizeof(variable) + sizeof(DWORD [variable]) + sizeof(message_fmt)

    ; exit code 
    mov eax, 1 ; 1 - system call sys_exit
    mov ebx, 0 ; 0 - error code 0
    int 0x80 ; processor interruption to run syscall