汇编系统调用

section .data                           ;Data segment
   userMsg db 'Please enter a number: ' ;Ask the user to enter a number
   lenUserMsg equ $-userMsg             ;The length of the message
   dispMsg db 'You have entered: '
   lendispMsg equ $-dispMsg                 

section .bss           ;Uninitialized data
   num resb 5

section .text          ;Code Segment
   global _start

_start:                ;User prompt
   mov eax, 4
   mov ebx, 1
   mov ecx, userMsg
   mov edx, lenUserMsg
   int 80h

   ;Read and store the user input
   mov eax, 3
   mov ebx, 2
   mov ecx, num  
   mov edx, 5          ;5 bytes (numeric, 1 for sign) of that @R_834_4045@ion
   int 80h

   ;Output the message 'The entered number is: '
   mov eax, 4
   mov ebx, 1
   mov ecx, dispMsg
   mov edx, lendispMsg
   int 80h  

   ;Output the number entered
   mov eax, 4
   mov ebx, 1
   mov ecx, num
   mov edx, 5
   int 80h  

   ; Exit code
   mov eax, 1
   mov ebx, 0
   int 80h