这应该将用户给出的字符串与文本文件的每一行
进行比较如果等于
，则必须打印该行但即使提供了正确的字符串，程序也不会打印任何内容
我可能对push和pop说明
.model small
.stack 100h
.data
filename db 255 dup(0)
text db 255 dup(0)
char db ?
text1 db 0dh, 0ah, 'Enter a string to search for: $'
text2 db 0dh, 0ah, 'Enter a filename : $'
string db 255 dup(0)
filehandle dw ?
.code
newline macro ;NEW LINE
;
mov dl, 10 ;
mov ah, 02h ;
int 21h ;
;
mov dl, 13 ;
mov ah, 02h ; ;
int 21h ;
endm ;NEW LINE
main:
mov ax, @data
mov ds, ax
mov ah, 09h
lea dx, text1 ;'Enter a string to search for: $'
int 21h
lea si, string
mov ah, 01h ;read character
string_input:
int 21h
cmp al, 0dh ;end of string
je zero_terminator2
mov [si], al
inc si
jmp string_input
zero_terminator2:
mov byte ptr [si], 0
mov ah, 09h
lea dx, text2
int 21h
lea si, filename
mov ah, 01h ;read character
char_input:
int 21h
cmp al, 0dh ;end of string
je zero_terminator
mov [si], al
inc si
jmp char_input
zero_terminator:
mov byte ptr [si], 0
open_file:
lea dx, filename
mov al, 0
mov ah, 3Dh ;open file
int 21h
mov filehandle, ax
lea si, text
read_line:
mov ah, 3Fh ;read file
mov bx, filehandle
lea dx, char
mov cx, 1
int 21h
cmp ax, 0 ;EOF
je EO_file
mov al, char
cmp al, 0ah ; line feed
je compare ; compare line with string given by user
mov [si], al
inc si
jmp read_line
EO_file:
push dx ;save dx for later use
push cx ;
push si ;
xor dx, dx
xor si, si
xor di, di
lea si, text
lea di, string
loop_cmp_EOF:
mov al, [si] ;Get the next byte from text
mov bl, [di] ;Get the next byte from string
cmp al, bl ;Compare bytes
jne end_it ;end of program if not equal
cmp al, 0 ;End of string. text=string
je last_print ;Print that line from text
inc si
inc di
jmp loop_cmp_EOF
last_print:
pop dx
pop cx
pop si
newline
lea dx, text ;DX=offset(address) of text
mov ah, 40h ;print
mov cx, si ;CX = # characters. Move pointer to last char to it
sub cx, dx ;Subtract the offset of text (in DX) from CX
;To get the actual number of chars in the buffer
mov bx, 1
int 21h
end_it:
mov ah, 4ch
int 21h
LF_print:
pop dx
pop cx
pop si
newline ;Macro
lea dx, text ;DX=offset(address) of text
mov ah, 40h ;print
mov cx, si ;CX = # characters. Move pointer to last char to it
sub cx, dx ;Subtract the offset of text (in DX) from CX
;To get the actual number of chars in the buffer
mov bx, 1
int 21h
mov si, dx ;Start from beginning of buffer
;(DX=beginning of text buffer)
jmp read_line
compare:
push dx ;save dx for later use
push cx ;
push si ;
xor dx, dx
xor si, si
xor di, di
lea si, text
lea di, string
loop_cmp:
mov al, [si] ;Get the next byte from text
mov bl, [di] ;Get the next byte from string
cmp al, bl ;Compare bytes
jne read_line ;Do not print. Take another line from text
cmp al, 0 ;End of string. text=string
je LF_print ;Print that line from text
inc si
inc di
jmp loop_cmp
end main
答案 0 :(得分：3)
一些问题。
您必须按相反的顺序pop寄存器。
push dx ;save dx for later use
push cx ;
push si ;
...
pop si
pop cx
pop dx
在 loop_cmp 中，你不能只是跳回 read_line ，因为你在堆栈上推了3个字，永远不会被弹出！
loop_cmp:
mov al, [si] ;Get the next byte from text
mov bl, [di] ;Get the next byte from string
cmp al, bl ;Compare bytes
jne read_line ;Do not print. Take another line from text
在 loop_cmp 中，您与零进行比较，但您将该行的结尾定义为换行符（= 10）。这不一致！
cmp al, 0 ;End of string. text=string
je LF_print ;Print that line from text