neomaniakov
18th October 2002 13:13 UTC

Global variables scope when !define is used
Hi all

I try to use Gloval variables with !define statement
when i receive values from extended DLL. I dont wanted to call
DLL twice or 5 time when i need some global value

When i use
CODE:--------------------------------------------
pluginDllName::Fill_S0
Pop $0
!define GLOBAL1 $0
CODE:END --------------------------------------------

if after that on some place in NSIS script
CODE:--------------------------------------------
StrCpy $0 "test2"
CODE:END --------------------------------------------
${GLOBAL1} value changes to "test2" too ?!?!? ...
I thought that statement "!define GLOBAL1 $0"
can be used for init ${GLOBAL1} with value of $0
not to Link with $0
What I suppose to do if I want to keep variable GLOBAL1
with global scope not to change when $0 changes ?
Some kind of:
CODE:--------------------------------------------
pluginDllName::Fill_S0
Pop $0
!define GLOBAL1
StrCpy ${GLOBAL1} $0
CODE:END --------------------------------------------

But in this case I receive Error when compile:
ERR: ---------------------------------------
StrCpy expects 2-2 parameters, got 1.
Usage: StrCpy $(user_var: output) str [maxlen] [startoffset]
ERR:END ---------------------------------------

kichik
18th October 2002 13:40 UTC

!define is a compile time command. It defines a symbol as a certain string at compile time, not runtime. If you define GLOBAL as $0 everytime the compiler will encouter ${GLOBAL} it will replce it with the string $0, which later, at runtime, will be translated to whatever value it holds.

You can't create more variables than what you already have in NSIS ($0...$9, $R0...$R9). Those variables are already global, you can use them everywhere in the script, and they will maintain the same value all over it.

If you want to keep a certain value in some variable you will have to reserve a variable from the existing variables for it. $R8 for example.

neomaniakov
18th October 2002 14:09 UTC

10ks kichik,

it helps me a lot, I'll fix my scripts

vtsaran
13th June 2003 19:24 UTC

Sorry. Do you mean to say that all variables in NSIS scripting language are global? If I used $R1 in function1, the $R1 in function2 will overwrite the first one? O gee, I hope this is not the case.

Lilla
13th June 2003 21:14 UTC

I am doing something similar and it is working fine so far.
I had problems until I finally figured out that the variable I used
($0) could not be used by any function, or else it would be overwritten. I need to test on WIN_VER in several different sections
and I didn't want to use $0, I wanted a meaningful name, like WIN_VER.

The way I see it now, it's like ${WIN_VER} is a friendly name for $0.
I'm new to NSIS, so if this is not a good way, please advise.

Call GetWindowsVersion
Pop $0 ; at this point $0 is "NT 4.0" or whatnot
!define WIN_VER $0 ; create a global variable
; MessageBox MB_OK "GetWindowsVersion ${WIN_VER}"
StrCmp ${WIN_VER} '98' ContinueAsk
StrCmp ${WIN_VER} '98 SE' Continue2
StrCmp ${WIN_VER} 'XP' Continue2

; Usage:
; Call GetWindowsVersion
; Pop $R0 ; at this point $R0 is "NT 4.0" or whatnot
Function GetWindowsVersion
Push $R0
Push $R1
... snip...

Lilla

Joost Verburg
13th June 2003 21:19 UTC

That's right. ${WINVER} will be replaced by $0. Maybe you'd better use a variable that is not so common, like $9.

Support for real user variables ($USER) will be added very soon (it's already in the development snapshot, but not enabled by default).

Sunjammer
13th June 2003 22:50 UTC

Originally posted by vtsaran
Sorry. Do you mean to say that all variables in NSIS scripting language are global? If I used $R1 in function1, the $R1 in function2 will overwrite the first one? O gee, I hope this is not the case.