[汇编] 比较2个字符串是否相等

; multi-segment executable file template.

data segment
STRING DB 'SPACE EXPLORERS INC'
PRLINE DB 'SPACE EXPLORERS INCE'
LAST   DB ' '
same   DB 'MATCH$'
nsame  DB 'NO MATCH$'
ends

stack segment
dw   128  dup(0)
ends

code segment
start:
; set segment registers:
mov ax, data
mov ds, ax
mov es, ax

; add your code here
mov cx,PRLINE-STRING        ;先判断长度，长度不相等直接不匹配
cmp cx,LAST-PRLINE
jnz NEQUAL

lea si,STRING               ;长度相等则逐个匹配
mov di,offset PRLINE
cld
rep cmpsb
jz  EQUAL
jnz NEQUAL

EQUAL:                      ;输出结果
lea dx,same
jmp NEXT
NEQUAL:
lea dx,nsame
NEXT:
mov ah, 9
int 21h        ; output string at ds:dx

; wait for any key....
mov ah, 1
int 21h

mov ax, 4c00h ; exit to operating system.
int 21h
ends

end start ; set entry point and stop the assembler.