下面是一个程序，使每个句子的第一个字母大写。但是，我需要修改这个程序，以便让任何其他单词字母小写。此外，可能会有很多句子。到目前为止，我已经注意到程序在我的电脑上运行得不是很好，但这可能不是我程序的错。无论如何，我在确定如何正确修改此程序以满足要求方面遇到了很多麻烦。非常感谢你提前了！
.model small
.stack 100h
.data
BUFSIZE EQU 4096 ; constant - the size of the buffer
input db 'data.txt',0 ; default input file
output db 'result.txt',0 ; default output file
msg1 db 'Choose data file [data.txt]: $'
msg2 db 10,13,'Choose result file [rezult.txt]: $'
msg3 db 10,13,'Error, the file could not be found, working with default file: data.txt $'
string1 db 11 dup (?) ; the name of input file
string2 db 11 dup (?) ; the name of result file
handle1 dw ? ; file handles
handle2 dw ?
buffer db BUFSIZE dup (' ') ; buffer
.code
mov ax, @data ; loading data segment
mov ds,ax
sub cx,cx
mov si, 80h
mov cl,es:[si]
cmp cx, 0
mov bx,0
je label1
inc si
inc si
dec cx
read: mov al,es:[si]
cmp al,' '
je second
mov string1[bx],al
inc si
inc bx
loop read
second:
mov string1[bx],0
mov bx,0
dec cx
looper: inc si
mov al,es:[si]
mov string2[bx],al
inc bx
loop looper
mov string2[bx],0
mov bx,100h
push bx
jmp open
label1: mov ah, 9
mov dx, offset msg1
int 21h
named: mov ah, 1h
int 21h
cmp al, 13
je eof1
mov string1[bx],al
inc bx
jmp named
eof1: mov string1[bx],00h
open: mov ah, 3dh
mov al, 2
mov dx, offset string1
int 21h
mov handle1, ax
mov ah, 59h
int 21h
cmp al, 2
je deflt
jmp cont
deflt: mov ah,9
mov dx,offset msg3
int 21h
mov ah, 3dh
mov al, 2
mov dx,offset input
int 21h
mov handle1,ax
cont: pop bx
cmp bx,100h
je creat2
mov ah, 9
mov dx, offset msg2
int 21h
mov bx,0000h
label2: mov ah, 1h
int 21h
cmp al, 13
je eof2
mov string2[bx],al
inc bx
jmp label2
eof2: mov string2[bx],0
cmp bx, 0
je creat1
jmp creat2
creat1: mov ah, 3ch
mov cx, 0
mov dx, offset output
int 21h
mov handle2, ax
mov ah, 3eh
mov bx, handle2
int 21h
mov ah, 3dh
mov al, 2
mov dx, offset output
int 21h
mov handle2, ax
jmp read_s
creat2: mov ah, 3ch
mov cx, 0
mov dx, offset string2
int 21h
mov handle2, ax
mov ah, 3eh
mov bx, handle2
int 21h
mov ah, 3dh
mov al, 2
mov dx, offset string2
int 21h
mov handle2, ax
doin:
read_s: mov ah, 3fh
mov bx, handle1
mov cx, BUFSIZE
mov dx, offset buffer
int 21h
cmp ax, 0
je theend
mov bx,ax
cmp buffer[0], 'z'
ja searching
cmp buffer[0], 'a'
jb searching
sub buffer[0], 32
dec bx
cc:
edit: cmp buffer[bx], '?'
je higher
cmp buffer[bx], '!'
je higher
cmp buffer[bx], '.'
je higher
jmp searching
higher: cmp buffer[bx+1], 'a'
jae lower
jmp searching
lower: cmp buffer[bx+1], 'z'
jbe changing;
jmp searching
changing: sub buffer[bx+1], 32
searching: dec bx ;
jnz cc
mov cx, ax
mov ah, 40h
mov bx, handle2
mov dx, offset buffer
int 21h
jmp doin
theend: mov ah, 3eh
int 21h
mov bx, handle1
int 21h
mov ah, 4ch
int 21h
end
答案 0 :(得分：1)
嗯，在这两种情况下你必须确保角色是一个大写 - 对于字符串中的第一个字符以及跟随＆＃39;之后的任何字符。 ＆＃39 ;.每个其他char应该是小写的。
首先创建一个函数，将'A' - 'a'（32）添加到char中，如果char在[a..z]范围内，则将其称为toupper.Now复制此函数并更改它以便减去'A'-'a'（32）来自char，如果它落在[A..Z]范围内。
现在只需遍历字符串，加载每个字符。如果它是空终止符，那么你就完成了。如果它是第一个char，则将其大写，然后将save保存为最后一个char，加载另一个字符并再次尝试。如果它不是null并且它不是第一个char，请检查最后一个char是否是空格。如果是，则将char大写，将其保存为last，然后返回以加载下一个char。但是，如果最后一个char不是空格，则将char设置为小写，将其保存为最后一个char，然后返回加载下一个char。
您可以将lastChar变量初始化为0，以确定当前char是否是字符串中的第一个char。 此外，一些注释和一些更有意义的标签名称将使您的代码更容易在以后返回，或更容易为其他人阅读。 ;） 这是一个值得进入的习惯。
这是一个有效的例子。输出为This Is My Message
;==========================================
; nasm toupper.asm -f bin -o toupper.com
;==========================================
[BITS 16]
[ORG 0x100] ; DOS .com program, no header, CS=DS
EntryPoint:
mov ax, 0x03 ; set text mode 3 - we should already be in this mode, done to clear the screen
int 0x10
push word myMessage
call makePrettyCase
push word myMessage
call printString
int 0x20 ; exit back to dos
;void printString(*str)
printString:
push bp
mov bp, sp
add bp, 4
mov si, [bp+0] ; ds:si ---> string
.getChar:
lodsb
test al, 0xff ; sets the flags as if we did 'and al, 0xff' - if the zero flag is set, there are no bits set in al, i.e it's 0
jz .printStringDone
mov ah, 0xe
int 0x10
jmp .getChar
.printStringDone:
pop bp
ret 2
; input:
; AL = char
; outpt:
; if al if an alpha char, ensures it is in range A-Z
toupper:
cmp al, 'a'
jb .toupperDone
cmp al, 'z'
ja .toupperDone
add al, 'A' - 'a'
.toupperDone:
ret
; input:
; AL = char
; outpt:
; if al if an alpha char, ensures it is in range a-z
tolower:
cmp al, 'A'
jb .tolowerDone
cmp al, 'Z'
ja .tolowerDone
sub al, 'A' - 'a'
.tolowerDone:
ret
; void makePrettyCase(char *string)
makePrettyCase:
push bp
mov bp, sp
add bp, 4 ; add 2 for the bp we just saved, and 2 for the return address. bp now points at out input var, a pointer to the string
pusha
mov si, [bp+0] ; point source index to string
mov di, si ; point dest index to string
xor dl, dl ; DL = lastChar, holds 0 for the first char in the string
mov dh, ' ' ; DH = spaceChar (' ') - holds the ascii code for a space
.getNextChar:
lodsb ; ds:[si] --> al, si = si+1
test al, 0xff
jz .makePrettyCaseDone
.checkIfFirstInString: ; if so, capitalize
; cmp byte [lastChar], 0
cmp dl, 0
jne .checkIfLastWasSpace
jmp .makeUpper
.checkIfLastWasSpace: ; if so, capitalize
;cmp byte [lastChar], spaceChar
cmp dl, dh
jne .makeLower
.makeUpper:
call toupper
stosb ; al --> es:[di], di = di+1
mov dl, al ; save this char as our lastChar
;mov byte [lastChar], al
jmp .getNextChar
.makeLower:
call tolower
stosb ; al --> es:[di], di = di+1
mov dl, al ; save this char as our lastChar
;mov byte [lastChar], al
jmp .getNextChar
.makePrettyCaseDone:
popa
pop bp
ret 2 ; return and remove the 2 bytes of the input var from the stack
;==========================================
[section .data]
myMessage db "THIS IS MY MESSAGE",0