CODEWITHSUNDEEP
assemblyx86masm32-bitirvine32
Danial Ahmed
Danial Ahmed

Reputation: 866

How to take string input in Assembly

I tried searching the forum for answer but all I got was taking input in 16bit or nasm. I tried using

push ecx
push edx
mov edx, offset myVar
mov ecx, sizeof myVar
call readstring

but it is not working as i expected. I am trying to take a string/character as input and increment it (Like from A to B) and print it on the screen. My code:

include irvine32.inc
.data
myVar BYTE ?
myVar2 BYTE ?
shifts DWORD 3
.code
main proc
    push ecx
    push edx
    mov edx, offset myVar
    mov ecx, sizeof myVar
    call readstring
    mov esi, offset [myVar]
    mov al,[esi]
    mov myVar2, al
    mov eax, DWORD PTR myVar2
    add eax, shifts
    mov DWORD PTR myVar2,eax
    mov edx, offset myVar2
    call writestring
    exit
main endp
end main

Code works fine if I initialize the myVar with a character and increment it but (adds a garbage ascii character to result too I dont know why) So I know the problem is with taking input.

Upvotes: 2

Views: 5112

Answers (1)

Danial Ahmed
Danial Ahmed

Reputation: 866

Sorry, Book had the answer.

.data
buffer BYTE 21 DUP(0)          ; input buffer
byteCount DWORD ?              ; holds counter
.code
mov   edx,OFFSET buffer         ; point to the buffer
mov   ecx,SIZEOF buffer         ; specify max characters
call  ReadString                ; input the string
mov   byteCount,eax             ; number of characters

Upvotes: 2

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