DOS.Printnumberofcharactersread|int21h,ah=0Ah

DOS中的“Print number of characters read”可以翻译为“打印读取的字符数”。对应的汇编指令为int 21h, ah = 0Ah。

以下是汇编代码示例，用于在DOS中打印读取的字符数：

section .data
    message db 0ah, "Enter a string: $"
    buffer db 20, 0
    input db ""

section .text
    global _start

_start:
    ; print message
    mov ah, 09h ; DOS function for printing string
    mov dx, message ; point to message
    int 21h ; call DOS

    ; read user input
    mov ah, 0Ah ; DOS function for buffered input
    mov dx, buffer ; point to buffer
    int 21h ; call DOS
    mov si, dx ; point to user input

    ; print user input
    mov ah, 09h ; DOS function for printing string
    mov dx, si ; point to user input
    int 21h ; call DOS

    ; print number of characters read
    mov ah, 02h ; DOS function for printing character to stdout
    mov dl, byte [buffer + 1] ; get the character count from buffer
    add dl, 30h ; convert to ascii value
    int 21h ; call DOS

    ; exit program
    mov ah, 4ch ; DOS function for exiting program
    int 21h ; call DOS

在该示例中，使用int 21h和ah = 02h来将字符计数打印到屏幕上。注意，字符计数位于输入缓冲区的第二个字节中。