Programming

What do you mean by a "lower level way" why cant you define "Receive" to be a 30 byte label and fill it with $ signs...which the code below does.

Code:

Receive db 30 dup('$')

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I was asking if someone would show me a way without using dup. Is is possible to do that just using the x86 instruction set?

---------- Post updated at 02:13 AM ---------- Previous update was at 02:11 AM ----------

Also if someone enters exactly 30 characters then it beeps.

Ok I fixed the beeping problem but I still haven't learned how to concatenate.
The fix is:

Code:

        ; Put this right after line 19
        mov ah, 09h
        mov dx, ENDLINE
        int 21h

ENDLINE db '$' ; was added

I basically send that after I send the variable receive and there are no problems. So solved but I would like to kow how to concatenate with assembly also if you want to post something.




I just thought of a better way to question my concat question.
How can I make dx + 30 = '$'
or maybe how can I make receive[30] = '$'

Well assembly aint C where libc guarantees that every literal will be suffixed with a NULL terminator...if you program in assembly language then learn to do most of the stuff yourself unless there is a lib of assembly routines that you can draw from...and there is no instruction in the x86 set that you can use for this because you need to know the last character of the entered string...and without that knowledge it is impossible.
Again the problem is not when the no of characters entered equals 30 but when someone enters less than 30 characters...and by initialising "Receive" to all $ signs you basically eliminate this issue.
If string length is equal to 30 then you can do this too...

Code:

Receive db 30 dup('$'),'$'

Why waste resources just for adding a $ to "Receive+30" when the db directive shown above does it for you.
Unless you know the last character of the entered string it isnt possible to emulate the C function strcat...so forget about it.
Again you are confused between a location dx+30 and its contents [dx+30] so first get that straight...the db directive shown above sets Receive[30]='$' or [dx+30]='$'

Well I solved my problem I was just hoping you would show me how to concatenate. Thanks anyway.

Well i showed you the one and only way it can be done...

Code:

Receive db 30 dup('$'),'$'