work with string parts

Index > Macroinstructions > work with string parts

Author

Thread

Lion17

Joined: 30 May 2006
Posts: 5

Lion17 03 Jun 2006, 19:54

have string

Code:

'abcd'

need string

Code:

'abc','d'+80h

if there way to do it?

03 Jun 2006, 19:54

comrade

Joined: 16 Jun 2003
Posts: 1150
Location: Russian Federation

comrade 03 Jun 2006, 20:32

in what context?
you can have it like this:

Code:

original db 'a','b','c','d'
modified db 'a','b','c','d'+80h

or like this:

Code:

mov eax,'abcd'
mov eax,<'abc','d'+80h>

03 Jun 2006, 20:32

comrade

Joined: 16 Jun 2003
Posts: 1150
Location: Russian Federation

comrade 03 Jun 2006, 20:36

Last one doesn't work, it should be:

Code:

mov eax,'abcd' 
mov eax,('abc' shr 8) OR ('d'+80h)

03 Jun 2006, 20:36

comrade

Joined: 16 Jun 2003
Posts: 1150
Location: Russian Federation

comrade 03 Jun 2006, 20:38

Or rather like this:

Code:

mov eax,('a' shl 24) OR ('b' shl 16) or ('c' shl 8) OR ('d')

03 Jun 2006, 20:38

comrade

Joined: 16 Jun 2003
Posts: 1150
Location: Russian Federation

comrade 03 Jun 2006, 20:38

You can swap the order (abcd -> dcba), if you like.

03 Jun 2006, 20:38

Lion17

Joined: 30 May 2006
Posts: 5

Lion17 04 Jun 2006, 06:55

the point is use ordinar string 'abc...def'
and I need modify only last character of it
how I can split string in mscro on two part:
header and last character?

04 Jun 2006, 06:55

comrade

Joined: 16 Jun 2003
Posts: 1150
Location: Russian Federation

comrade 04 Jun 2006, 08:23

please provide more context

how/where are you trying to use this technique?

04 Jun 2006, 08:23

Lion17

Joined: 30 May 2006
Posts: 5

Lion17 04 Jun 2006, 16:07

I use strings with end marked by hi bit of last character.
now I define string with next code:

Code:

db 'Sample strin','g'+80h

but I want macro to define such strings by macro with code like:

Code:

EndBitString 'Sample string'

04 Jun 2006, 16:07

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8354
Location: Kraków, Poland

Tomasz Grysztar 04 Jun 2006, 16:29

Code:

macro EndBitString str
{
  db str
  local lastchr
  load lastchr byte from $-1
  lastchr=lastchr or 80h
  store byte lastchr at $-1
}

04 Jun 2006, 16:29

LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 04 Jun 2006, 17:10

Code:

struc EndBitString str 
{ 
  . db str 
  local ..lastchr 
  load ..lastchr byte from $-1 
  ..lastchr=..lastchr or 80h 
  store byte ..lastchr at $-1 
}

In case you want things like

Code:

aString EndBitString 'Hello World'

Tomasz, is not better to use local names prefixed with two dots?

04 Jun 2006, 17:10

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8354
Location: Kraków, Poland

Tomasz Grysztar 04 Jun 2006, 18:06

It matters when you use those names as labels, but here it is a numeric variable ("=" and "load" define numeric variables).

04 Jun 2006, 18:06

LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 04 Jun 2006, 18:19

Code:

.a = '0'
b = 1
c = .a + b
display c

works

Thanks for the info!!

04 Jun 2006, 18:19

< Last Thread | Next Thread >

Forum Rules:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum