问题
How do I remove everything in the string after the '?' ? The code I have so far searches for the '?'. How do I proceed from there?
This is my code.
INCLUDE Irvine32.inc
.data
source BYTE "Is this a string? Enter y for yes, and n for no",0
.code
main PROC
mov edi, OFFSET source
mov al, '?' ; search for ?
mov ecx, LENGTHOF source
cld
repne scasb ; repeat while not equal
jnz quit
dec edi ; edi points to ?
end main
回答1:
You can replace everything after the "?" by zeroes, so all the characters after "?" are been "removed" :
INCLUDE Irvine32.inc
.data
source BYTE "Is this a string? Enter y for yes, and n for no",0
.code
main PROC
mov edi, OFFSET source
mov al, '?' ; search for ?
mov ecx, LENGTHOF source
cld
repne scasb ; repeat while not equal
jnz quit
dec edi ; edi points to ?
;REPLACE ALL CHARACTERS BY "AL" (ZERO) STARTING WHERE "EDI" WAS AND
;FINISH WHEN "ECX" == 0.
mov al, 0 ;<=====================================
repne stosb ;<=====================================
end main
Notice how we are using the values that EDI and ECX have after searching for "?".
来源：https://stackoverflow.com/questions/37036950/how-do-i-remove-everything-after-a-certain-character-in-a-string