我需要提示用户一个消息,告诉他写一个数字,然后存储此数字并对其进行一些操作
在INT 21h中搜索后,我发现了这一点:

INT 21h / AH=1 - read character from standard input, with echo, result is stored in AL.
if there is no character in the keyboard buffer, the function waits until any key is pressed.

example:

    mov ah, 1
    int 21h


主要问题是,这仅读取一个字符并将其表示为ASCII
所以如果我需要写数字“ 357”
我将其读为3,5,7

这不是我的目标。
有任何想法吗 ?

最佳答案

When you managed to get the user input,将其指针放在ESI中(ESI =字符串的地址)

.DATA
myNumber BYTE "12345",0        ;for test purpose I declare a string '12345'

Main Proc
    xor ebx,ebx                ;EBX = 0
    mov  esi,offset myNumber   ;ESI points to '12345'

loopme:

    lodsb                      ;load the first byte pointed by ESI in al

    cmp al,'0'                 ;check if it's an ascii number [0-9]
    jb noascii                 ;not ascii, exit
    cmp al,'9'                 ;check the if it's an ascii number [0-9]
    ja noascii                 ;not ascii, exit

    sub al,30h                 ;ascii '0' = 30h, ascii '1' = 31h ...etc.
    cbw                        ;byte to word
    cwd                        ;word to dword
    push eax
    mov eax,ebx                ;EBX will contain '12345' in hexadecimal
    mov ecx,10
    mul ecx                    ;AX=AX*10
    mov ebx,eax
    pop eax
    add ebx,eax
    jmp loopme                 ;continue until ESI points to a non-ascii [0-9] character
    noascii:
    ret                        ;EBX = 0x00003039 = 12345
Main EndP

07-24 09:38
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