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Question

我需要从带有缓冲区的键盘读取字符串。

在示例和文献的帮助下，我设法编写了这段代码，但是当我尝试打印出我插入的字符串时，它只是给我一条消息“再次输入你的字符串：”。

我的代码应该更改一下，以便打印我插入的内容？

.model small

stack 100h

.data

    ;reading buffer
    buffSize DB 255       ;Number of maximum characters than can be read
    read DB ?             ;Number of characters that was read
    buffer  DB 255 dup (?) ;Read characters are placed here

    ;Other data
    input DB "Input your string: $",13,10
.code

Start:

    MOV ax,@data
    MOV ds,ax

    MOV ah,9
    MOV dx, OFFSET input
    INT 21h                     ;Prints input string

    MOV ah, 0Ah
    MOV dx, OFFSET buffSize
    INT 21h                     ;Text is read

    MOV bx, OFFSET buffer       ;Address of buffer is inserted to bx
    MOV cl, read                ;Content of read is inserted to cl
    MOV ch, 0                   ;In cl there is a number of inserted characters

    MOV byte ptr [ds:bx], '$'

    MOV ah, 9
    MOV dx, OFFSET buffer
    INT 21h

    MOV ah,4Ch
    INT 21h
END Start

Answer 1

input DB "Input your string: "
nextLine db "$",13,10

nextLine 不会做太多。将“$”置于后面13,10 Best还会在同一行上划分输入文字。

input    db "Input your string: $"
nextLine db 13,10,"$"

buffSize DB 255       ;Number of maximum characters than can be read
read DB ?             ;Number of characters that was read
buffer  DB 25 dup (?) ;Read characters are placed here

如果允许输入255个字符，还应该定义一个足够大的缓冲区！ 25 dup (?)远小于255的规定大小。

要重新打印输入，请在文字后面添加 $ ：

mov  bx, OFFSET buffer     ;Start of the text
add  bl, read              ; plus the number of characters in the text
adc  bh, 0                 ;Maybe there was a carry from previous addition!
mov  byte ptr [bx], "$"    ;DOS needs string $-terminated
mov  ah, 09h               ;DOS.DisplayString
mov  dx, OFFSET buffer
int  21h

Answer 2

你把'$'放在缓冲区的开头。尝试

    mov di, cx
    mov [bx+di], '$'