Simple problem

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HtLrR

Joined: 04 Aug 2009
Posts: 5

HtLrR 04 Aug 2009, 01:03

hi every body

I'm begging with assembly

I have simple question

look at the picture

and this my Answer

Code:

.386
.model flat ,stdcall
OPTION CASEMAP:NONE
include windows.inc
include kernel32.inc
include masm32.inc
includelib kernel32.lib
includelib masm32.lib
.DATA
MasgName db "Enter the name  ",0
endl db 00ah,00dh ,0
good db " good name",0
Exit db "Exit   ",0

.DATA?
name1 db ?
.code
start:

invoke StdOut ,addr MasgName
invoke StdIn,addr name1,10
invoke StdOut ,addr name1
invoke StdOut ,addr good
invoke StdOut ,addr endl
invoke StdOut ,addr Exit
invoke StdIn,addr name1,100

invoke ExitProcess,0
end start

04 Aug 2009, 01:03

shoorick

Joined: 25 Feb 2005
Posts: 1614
Location: Ukraine

shoorick 04 Aug 2009, 05:41

so, where is the question exactly? some tips:

1.

Code:

name1 db 16 dup(?)

Code:

invoke StdIn,addr name1,10
mov [name1 + eax - 2],0 ; removing trailing 0Dh,0Ah
invoke StdOut ,addr name1
invoke StdOut ,addr good

3.it is MASM, while here is FASM board Wink

Code:

endl db 00dh,00ah,0

04 Aug 2009, 05:41

HtLrR

Joined: 04 Aug 2009
Posts: 5

HtLrR 04 Aug 2009, 12:20

Thank you for quick reply

if you can't see the picture Smile

this is a question
I- write a console program that receive the name of the user then print it , like this :

note that the program should take the name then print it followed by the sentence "is da best" .
thanks it work now Smile

but how..!!!!

if you can explain this Embarassed

Code:

mov [name1 + eax - 2],0 ;

Sorry ...... Crying or Very sad

04 Aug 2009, 12:20

shoorick

Joined: 25 Feb 2005
Posts: 1614
Location: Ukraine

shoorick 04 Aug 2009, 12:34

you said: "this my Answer" - with this i've supposed that you have wrote that code.
even if not it is working code and there is no need to be a genius to understand how does it work and what to change to get "is da best" there.

do not mix "help" and "do it all instead of me"

mov [name1 + eax - 2],0 - string after StdIn (eg. name) will have "end of line" in the end (two bytes 0Dh,0Ah). since StdIn returns entered striing length in eax, it is ease to cut off this eol (put "0" there)

04 Aug 2009, 12:34

HtLrR

Joined: 04 Aug 2009
Posts: 5

HtLrR 04 Aug 2009, 22:56

thanks for your help Smile

if you please what's the different between

Code:

name1 db 16 dup(?)

and

Code:

name1 db ?

)

04 Aug 2009, 22:56

shoorick

Joined: 25 Feb 2005
Posts: 1614
Location: Ukraine

shoorick 05 Aug 2009, 04:28

name1 db ? allocates one uninitialized byte
name1 db 16 dup(?) allocates 16 uninitialized bytes

you need at least 10 to fit entered name (StdIn,10)

the original code does not fails due to spare space between sections. if in original code name1 were followed with another data, it would be destroyed while entering name there

05 Aug 2009, 04:28

HtLrR

Joined: 04 Aug 2009
Posts: 5

HtLrR 06 Aug 2009, 11:04

Thanks shoorick

06 Aug 2009, 11:04

Pirata Derek

Joined: 31 Oct 2008
Posts: 259
Location: Italy

Pirata Derek 27 Aug 2009, 17:27

Also you can use the "Reserve" declaration:

Code:

rb 10 ; reserve 10 uninizialized bytes
rw 3 ; reserve 3 uninizialized words (3 x 2 btyes)
rd 1 ; reserve 1 double word

They have the same function as:

Code:

db 5 dup (?) ; equivalent to rb 5

Also if you put all the reserved data in the end of a section
you can assemble a file smaller than you imagine!!!

This program will be 1024 bytes...

Code:

; Demonstration 1
Format PE GUI 5.0
entry start
section '.code' code readable executable
start: ret ; simply exit process

JUNK rb 10000h ; the reserved INVISIBLE data

But this one will be 66560 bytes!

Code:

; Demonstration 2
Format PE GUI 5.0
entry start
section '.code' code readable executable
start: ret ; simply exit process

JUNK rb 10000h
var_1 db 0 ; this will increase the size to declare itself

27 Aug 2009, 17:27

Fanael

Joined: 03 Jul 2009
Posts: 168

Fanael 27 Aug 2009, 18:11

Pirata, it won't even compile - look at first post, HtLrR is using MASM, not FASM (very stupid idea IMO).

27 Aug 2009, 18:11

Pirata Derek

Joined: 31 Oct 2008
Posts: 259
Location: Italy

Pirata Derek 27 Aug 2009, 18:31

Yes, you're right Embarassed

But it can always be a valid help for who don't know or doesn't use the Reserve declaration in fasm.

There're much more people that can read that post and learn something from it.

27 Aug 2009, 18:31

HtLrR

Joined: 04 Aug 2009
Posts: 5

HtLrR 29 Aug 2009, 14:17

thanks Pirata Derek i will try to understand it

29 Aug 2009, 14:17

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