Some basic assembly questions involving user input

[sharpnova]

I'm trying to modify some sample codes to get a handle on ASM.

I don't have a problem with output, but I can't seem to get input working correctly.

How would I for example input a string from the user?

I've seen ReadString mentioned here and there but can't get any good documentation on how to implement this procedure that makes sense to a complete novice.


Also how could I input some integers? I want to have an array of integers that the user can input into but I don't even have a clue what command you use in ASM for inputting an integer.

[PBrennick]

sharpnova.

Also how could I input some integers? I want to have an array of integers that the user can input into but I don't even have a clue what command you use in ASM for inputting an integer.

Specifically, you don't. You would input characters that represent integers. Once you get the characters into a buffer or something, you process them into integers. It is easy to convert 37h to 7, for example.

Are you writing a console app? The answer to your first question would depend upon your answer to my question. If it is a console app, Hutch has already done the work for you. wait_key, for example, quickly comes to my mind but there is more than one method in his library. For a windows app, there is GetTextInput (I think).

Anyway, take a look at what he has in there. There is no sense in re-inventing the wheel.

Paul

[ToutEnMasm]

Hello,

How would I for example input a string from the user?

For this ,use a window and a dialog box with an edit control.

[MichaelW]

sharpnova,

The ReadString procedure most frequently mentioned here is from the Irvine32 library and it is designed to read a string from the console. If you have that library then you should have the source for it, and a description of how to use it should be in the comment header just above the procedure definition. If you do not have that library then there are multiple alternatives, but without knowing more about what you're trying to do and what libraries and code you have available (MASM32, GeneSys, Irvine32, etc), it's hard to know what to suggest.

[Vortex]

Hi sharpnova,

There are functions provided with masm32.lib to receive keyboard input and convert NULL terminated strings to DWORD.

Here is a quick example :

Code Select Expand


include     InputTest.inc

BUFFER_LENGTH  = 100
BUFFER_LENGTH2 = 16

.data

message1    db 'Type a string :',13,10,0
message2    db 'Type an integer, x = ',13,10,0
format1     db 'String = %s',13,10,'2 * x + 1 = %d',13,10,0

.data?

string      db BUFFER_LENGTH  dup(?)
integer     db BUFFER_LENGTH2 dup(?)
buffer      db 256 dup(?)

.code

start:

    invoke  StdOut,ADDR message1            ; output a NULL terminated string
    invoke  StdIn,ADDR string,BUFFER_LENGTH ; read keyboard input from console
    invoke  StdOut,ADDR message2
    invoke  StdIn,ADDR integer,BUFFER_LENGTH2
                                            ; StdIn returns the lenght of the input text
    mov     BYTE PTR [integer+eax-2],0      ; remove the CR+LF terminator
    invoke  atodw,ADDR integer              ; convert the decimal string to dword
    shl     eax,1                           ; multiply by 2
    inc     eax                             ; add 1

    invoke  wsprintf,ADDR buffer,ADDR format1,ADDR string,eax
    invoke  StdOut,ADDR buffer
    invoke  ExitProcess,0

END start

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