我如何获取用户输入与NASM？ [英] How do I get user input with NASM?

问题描述

该方案需要采取在来自用户的简单的字符串并显示它后面。我已经得到程序采取从用户的输入，但我似乎无法储存。以下是我迄今为止：

The program needs to take in a simple string from the user and display it back. I have gotten the program to take input from the user but I can't seem to store it. Here is what I have so far:

BITS 32
global _main
section .data

prompt db "Enter a string: ", 13, 10, '$'
input resd 1 ; something I can using to store the users input.

name db "Name: ******", 13, 10,'$'
StudentID db "********", 13, 10, '$'
InBoxID db "*************", 13, 10, '$'
Assignment db "************", 13, 10, '$'
version db "***************", 13, 10, '$'

section .text
_main:

mov ah, 9
mov edx, prompt
int 21h
mov ah, 08h
while:
    int 21h
            ; some code that should store the input.
    mov [input], al
    cmp al, 13
    jz endwhile
    jmp while
endwhile:

mov ah, 9
    ; displaying the input.

mov edx, name
int 21h
mov edx, StudentID
int 21h
mov edx, InBoxID
int 21h
mov edx, Assignment
int 21h
mov edx, version
int 21h
ret

我这个组装使用NASM。

I am assembling this using NASM.

推荐答案

您正在阅读只是人物没有存储起来。而不是存储成输入的，您应该保存AL直接进入StudentID / InBoxID /转让/版本。可以在存储器利用它们的相对位置，并写一个单一的环，以填补所有的人，如在一个连续的空间。

You're only reading the characters without storing them. Instead of storing into that 'input', you should store AL either directly into StudentID/InBoxID/Assignment/Version. You could take advantage of their relative positions in memory and write a single loop to fill all of them, as in a contiguous space.

这可能是这样的：

; For each string already padded with 13, 10, $
; at the end, use the following:
mov ah, 08h
mov edi, string
mov ecx, max_chars
cld
while:
        int 21h
        stosb         ; store the character and increment edi
        cmp ecx, 1    ; have we exhausted the space?
        jz out
        dec ecx
        cmp al, 13
        jz terminate  ; pad the end
        jmp while
terminate:
        mov al, 10
        stosb
        mov al, '$'
        stosb
out:
        ; you can ret here if you wish

我没有测试，所以它可能有失误吧。

I didn't test, so it might have mistakes in it.

您也可以用其他的DOS函数，具体 INT21H / 0AH 。它可能是更理想的和/或更容易。

Or you could use other DOS functions, specifically INT21h/0Ah. It could be more optimal and/or easier.

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