ughisuck
Joined: 31 Mar 2021
Posts: 1
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Hi, I'm trying to make a calculator to learn and I'm running into an issue when I use ReadConsole. It's loading the value but then I want to chop off the extra string characters so I can convert the string to a decimal representation but I'm struggling just at the string part and chopping off the extra two bytes "\r\n"
Here's the code, int3 is already in the area I was trying (I put comments on what I'm thinking as well).
Essentially want to take the two inputs:
1. 100 which turns into "100\r\n"
2. 50 which turns into "50\r\n"
3. Chop off \r\n on both
4. Convert 100 and 50 to decimal
5. Add them
Would love tips on at least getting to 3, if any tips on 4 I'd really appreciate it so much. Thank you.
format PE64 Console
include 'win64axp.inc'
.code
start:
sub rsp,8
invoke GetStdHandle,STD_INPUT_HANDLE
mov [stdin],eax
invoke GetStdHandle,STD_OUTPUT_HANDLE
mov [stdout],eax
; outer loop - command
invoke WriteConsole,[stdout],addr sError,sErrorSz,addr outSz,0
invoke ReadConsole,[stdin],buff,1024,addr count,0
mov edi,buff
; ? cmds
cmp byte [edi],'+'
je HANDLEADD
cmp byte [edi],'-'
je HANDLESUB
cmp byte [edi],'*'
je HANDLEMUL
cmp byte [edi],'/'
je HANDLEDIV
jmp error
jmp error
error:
mov rcx,sError
invoke WriteConsole,[stdout],addr sError,sErrorSz, addr count, 0
jmp clear
HANDLEADD:
push r12
push r13
invoke WriteConsole,[stdout],addr sAdd,sAddSz,addr outSz,0
invoke ReadConsole,[stdin],buff,1024,addr count,0
;:: If I type in "100" the buffer will have "100\r\n"
;:: I want to take the bytes written to -2 and put it anywhere (stack or register is fine)
;:: So basically just push 100. In my mind this makes sense: push count-2 [buff-count-2] (so it would only push the byte size of count - 2 bytes)
;:: but all I'm getting is something like the address and not sure how to take off the two bytes, maybe I could do string operation but not sure?
;:: push count-2
;::
;:: 0000000000402000 31 30 30 0D 0A 00 00 00 00 00 00 00 00 00 00 00 100.............
mov eax,buff
int3
push buff
; mov by
push qword [eax]
push count-2
int3
movzx r12,byte [buff]
; ask for second number
invoke WriteConsole,[stdout],addr sAdd2,sAdd2Sz,addr outSz,0
invoke ReadConsole,[stdin],buff,1024,addr count,0
int3
movzx r13,byte [buff]
; add it!
add r12,r13
pop r13
pop r12
jmp clear
HANDLESUB:
invoke WriteConsole,[stdout],addr sAdd,sErrorSz, addr count, 0
jmp clear
HANDLEMUL:
invoke WriteConsole,[stdout],addr sAdd,sErrorSz, addr count, 0
jmp clear
HANDLEDIV:
invoke WriteConsole,[stdout],addr sAdd,sErrorSz, addr count, 0
jmp clear
equal:
invoke WriteConsole,[stdout],addr sAdd,sErrorSz, addr count, 0
jmp clear
notequal:
invoke WriteConsole,[stdout],addr sAdd,sErrorSz, addr count, 0
jmp clear
clear:
xor rcx,rcx
xor rdi,rdi
xor rsi,rsi
xor eax,eax
xor ecx,ecx
jmp start
.data
buff rb 1024
buff2 rb 1024
count dd ?
outSz dd ?
count2 dd ?
stdin dd ?
stdout dd ?
pMath dd 0
sError db 'Try +, -, *, /',10,0
sErrorSz = $ - sError
sEqual db 'It is equal',10,0
sEqualSz = $ - sEqual
sNotEqual db 'Not Equal',10,0
sNotEqualSz = $ - sNotEqual
sAdd db 'First number to add?',10,0
sAddSz = $ - sAdd
sAdd2 db 'Second number?',10,0
sAdd2Sz = $ - sAdd2
sMul db 'First number to multiply?',10,0
sMulSz = $ - sMul
sMul2 db 'Second number to multiply?',10,0
sMul2Sz = $ - sMul2
sSub db 'First number to subtract?',10,0
sSubSz = $ - sSub
sSub2 db 'Second number to subtract?',10,0
sSub2Sz = $ - sSub2
sDiv db 'First number to divide?',10,0
sDivSz = $ - sDiv
sDiv2 db 'Second number to divide?',10,0
sDiv2Sz = $ - sDiv2
.end start
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> Windows > Please help, lost, confused... would appreciate it.
31 Mar 2021, 14:01
