在裝配中接受用戶輸入嗎？ 簡單程序（在macOS上）

Question

我在使用這個簡單的程序時遇到了一些麻煩，該程序接受了用戶的名字並顯示“ Hello，name here”

到目前為止，這是我的代碼...

%define SYSCALL_WRITE 0x2000004
%define SYSCALL_EXIT  0x2000001
%define SYSCALL_READ  0x2000003

SECTION .data
  prompt db "Enter name "
  text2 db "Hello, "

SECTION .bss
  name resb 16

SECTION .text
  global _start

_start:
  call _printText1
  call _getInput
  call _printText2
  call _printName
  mov rax, SYSCALL_EXIT
  mov rdi, 0
  syscall

_printText1:
  mov rax, SYSCALL_WRITE
  mov rdi, 1
  mov rsi, prompt
  mov rdx, 11
  syscall
  ret

_getInput:
  mov rax, SYSCALL_READ
  mov rdi, 0
  mov rsi, name
  mov rdx, 1
  syscall
  ret

_printText2:
  mov rax, SYSCALL_WRITE
  mov rdi, 1
  mov rsi, text2
  mov rdx, 7  
  syscall
  ret

_printName:
  mov rax, SYSCALL_WRITE
  mov rdi, 1
  mov rsi, name
  mov rdx, 16
  syscall
  ret

當我執行它時，輸出不會顯示“ Hello，”。 輸入的名稱的第一個字母打印在下一個命令行之前...

nMy-MacBook:Assembly username$ ame

名稱的其余部分被接受為命令參數，系統會對此進行回復

-bash: ame: command not found

我到底在做什么錯？ 我刪除了_getInput和_printName函數，它仍然只打印“輸入名稱”而不打印“ Hello”。

謝謝。

Answer 1

在組裝中，您必須考慮到每一點； 特別是在進行輸入和輸出時。

以下是您對RDX進行編輯的部分代碼，其中我選擇了任意長度。

最后一行顯示了命令行程序的執行，提示，用戶輸入以及最終輸出。

; reference:
; https://stackoverflow.com/questions/47889972/accepting-user-input-in-assembly-simple-program-on-macos

; lsb_release -a
; Distributor ID: Ubuntu
; Description:    Ubuntu 16.04.3 LTS
; Release:        16.04
; Codename:       xenial

; assemble and link
; nasm -f elf64 -g -F dwarf srsrso_001.s -o srsrso_001.o  && ld srsrso_001.o -o srsrso_001

;%define SYSCALL_WRITE 0x2000004
;%define SYSCALL_EXIT  0x2000001
;%define SYSCALL_READ  0x2000003

SECTION .data
  prompt db "Enter name "
  text2 db "Hello, ",0xa,0

        SYSCALL_WRITE equ       1
        SYSCALL_EXIT  equ       60
        SYSCALL_READ  equ       0

SECTION .bss
  name resb 0xff                ; some length

SECTION .text
  global _start

_start:
 call _printText1
 call _getInput
 call _printText2
 call _printName

  mov rax, 60
  mov rdi, 0
  syscall

_printText1:
  mov rax, SYSCALL_WRITE
  mov rdi, 1
  mov rsi, prompt
  mov rdx, 11
  syscall
  ret

_getInput:
  mov rax, SYSCALL_READ
  mov rdi, 0
  mov rsi, name
  mov rdx, 0xff ; some length
  syscall
  ret

_printText2:
  mov rax, SYSCALL_WRITE
  mov rdi, 1
  mov rsi, text2
  mov rdx, 7
  syscall
  ret

_printName:
  mov rax, SYSCALL_WRITE
  mov rdi, 1
  mov rsi, name
  mov rdx, 0xff ; some length
  syscall
  ret

輸出示例：

$ ./srsrso_001
Enter name David John Lewis Benjamen Kyle Smith-Wenson
Hello, David John Lewis Benjamen Kyle Smith-Wenson