Simple console output

[hamper]

One of the biggest hurdles I've faced while trying to learn assembly language programming (which I'm still doing) is how to output some simple variables to the console, so that I can see what happens when I'm trying things out. Just some humble variables - an unsigned integer, a signed integer, a floating point and a string. I searched but could only find examples that did literal strings, or examples that seemed like gibberish at my level - i.e. not much help. So after much sussing out I've finally managed to put together a simple little console program that does the trick, and I'm posting it here in case it comes in handy for anyone else trying to learn assembly language as I am:

;######################################################################################
; Output to console using printf and print          CONSOLE BUILD            conout.asm
;######################################################################################

; Make sure any floating point values are declared as real8
; Make sure any integer values are declared as either sdword or dword

; printf operates in the normal C manner and can take the following (useful) format specifiers:
;   i   signed integer
;   u   unsigned integer
;   f   floating point
; All the usual escape sequences can be used, for example \n

; print outputs any predefined nul-terminated string
;    so assuming for example you have already defined
;       mystring byte "hello",13,10,0
;    then the syntax is
;       print addr mystring

;--------------------------------------------------------------------------------------

.686
.model flat, stdcall
option casemap :none

; the following are the MINIMUM include and includelib files required for printf and
; print to function properly, but you may need to include others depending on what you
; wish to do if it is more than the small example shown below

include kernel32.inc
include macros.asm
include msvcrt.inc
include masm32.inc
includelib kernel32
includelib msvcrt
includelib masm32

.data
mysdword sdword -1234
mydword dword 5678
myreal8 real8 123.456789
mystring byte "Hello, World",13,10,0

.code
start:

printf("My sdword is %i\n",mysdword)
printf("My dword is  %u\n",mydword)
printf("My real8 is  %f\n",myreal8)
print addr mystring

printf("\n\n")
exit

end start

[herge]

Hi hamper:

try:

Code Select Expand


include \masm32\include\masm32rt.inc


Which is this:

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; \MASM32\INCLUDE\MASM32RT.inc Wednesday, March 18, 2009 4:21 AM
comment * «««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««

    The MASM32 Runtime Library include file.

    Differing from most compilers, MASM does not contain any built in
    run time library so it is difficult for a programmer starting with
    MASM to to get any code up and running without having to learn a lot
    of extra information just to do basic things.
   
    This file simplifies entry into assembler programming by making the
    full capacity of the MASM32 library, macro system and include files
    available to programmers undertaking this quest.

    It specifies the normal conditions for building a 32 bit Windows
    program with the minimum processor type, memory model and the need
    for case sensitive capacity.

    The include files are declared in the correct order so that the
    windows.inc file is always first followed by static libraries and
    import libraries for Windows API functions.

    Where there is a corresponding library for either static or import
    libraries, it is included after the include files.

    NOTE : It is to the advantage of the programmer once they have their
    basic code up and running to properly understand the architecture
    of a MASM executable file so that they can construct their own
    projects to more accurately reflect their own application design.

  ««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««« *

      .486                                      ; create 32 bit code
      .model flat, stdcall                      ; 32 bit memory model
      option casemap :none                      ; case sensitive

;     include files
;     ~~~~~~~~~~~~~
      include \masm32\include\windows.inc       ; main windows include file
      include \masm32\include\masm32.inc        ; masm32 library include

    ; -------------------------
    ; Windows API include files
    ; -------------------------
      include \masm32\include\gdi32.inc
      include \masm32\include\user32.inc
      include \masm32\include\kernel32.inc
      include \masm32\include\Comctl32.inc
      include \masm32\include\comdlg32.inc
      include \masm32\include\shell32.inc
      include \masm32\include\oleaut32.inc
      include \masm32\include\ole32.inc
      include \masm32\include\msvcrt.inc

      include \masm32\include\dialogs.inc       ; macro file for dialogs
      include \masm32\macros\macros.asm         ; masm32 macro file

;     libraries
;     ~~~~~~~~~
      includelib \masm32\lib\masm32.lib         ; masm32 static library

    ; ------------------------------------------
    ; import libraries for Windows API functions
    ; ------------------------------------------
      includelib \masm32\lib\gdi32.lib
      includelib \masm32\lib\user32.lib
      includelib \masm32\lib\kernel32.lib
      includelib \masm32\lib\Comctl32.lib
      includelib \masm32\lib\comdlg32.lib
      includelib \masm32\lib\shell32.lib
      includelib \masm32\lib\oleaut32.lib
      includelib \masm32\lib\ole32.lib
      includelib \masm32\lib\msvcrt.lib

; «««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««



And note the windows.inc
which should always be first.

Regards herge

[herge]

 Hi hamper:

Code Select Expand


mystring byte "hello",13,10,0


try:

Code Select Expand


mystring db "hello",13,10,0


Code Select Expand


.data
date_buf db 260 dup (0)
read_buf    DB    128 DUP (0)
crlf        DB  13,0
Sfile    dd 0 ; Std Output(Console)
ByteSent dd 0 ; Byte Count
ByteRead dd 0 ; Byte Count

.code
      invoke GetStdHandle, STD_OUTPUT_HANDLE
      mov   Sfile, eax
      invoke WriteConsole, Sfile, addr date_buf, 128, addr ByteSent, 0
      invoke WriteConsole, Sfile, addr crlf, 2, addr ByteSent, 0
      invoke WriteConsole, Sfile, addr read_buf, 128, addr ByteSent, 0
      invoke WriteConsole, Sfile, addr crlf, 2, addr ByteSent, 0
      inkey "Hit any Key"; masm32\include\macros\macros.asm
      invoke CloseHandle, Sfile
      invoke ExitProcess, 0


You will have to put data in read_buf and date_buf
yourself  but I think you will get the idea.

For windows APIs see if you can find this file:win32.hlp
It's a god send. Just google it and download it.

Regards herge

[japheth]

Code Select Expand


mystring byte "hello",13,10,0


try:

Code Select Expand


mystring db "hello",13,10,0


herge, the first definition is quite fine. You're only confusing a newbie with such proposals. Actually, hamper didn't even ask for help, on the contrary, he offered help for others.

[MichaelW]

hamper,

AFAIK the cfm$ macro, and its supporting macros, that the printf macro calls to process the format string, passes the format specification part of the string to the CRT function as is, so you can use the full range of types, flags, etc, for example:

Code Select Expand


.data
mysdword  sdword -1234
mydword   dword 5678
myqword   qword 123456789123456789
myreal8   real8 123.456789
mystring  byte "Hello, World",13,10,0

.code
start:

printf("My sdword is %i\n",mysdword)
printf("My dword is  %u\n",mydword)
printf("My dword is  %Xh\n",mydword)
printf("My qword is  %I64d\n",myqword)
printf("My real8 is  %f\n",myreal8)
printf("My real8 is  %.15f\n",myreal8)
printf("My string is %s\n\n",addr mystring)


[hutch--]

Hi hamper,

Welcome on board and compliments on your posted example. There are easier way to do many of these things but you have done well with your example.

[Gunther]

Hi  hamper,

welcome to the forum and have fun.  :t

Gunther

[hamper]

Thanks all.

I realise that my example might not be the prettiest way of doing things, but at least it works and I can understand it (at least on the surface, what goes on behind the scenes to make it that simple on the surface I can't imagine). It's amazing how often I've used it so far, just trying things out to see what happens to bytes, words, doublewords and strings etc. when you play around with them -- all part of the learning process I guess.

Right, time for some structures of pointers to pass as parameters to procedures for pointers to structures...

[herge]

Hi Hamper:

Welcome to the forum.

Regards herge

[Vortex]

Hi hamper,

Welcome to the forum.