Longest an ASCIIZ String Can Be?

[Scott Slater]

What is the longest that an Asciiz string can be? I was trying to
create a 1 megabyte Asciiz string and it causes a Stack fault in
Windows. The most I can make it is around 200 KB. Anyone have any
info on this?


Scott


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[Lance Edmonds]

LOCAL scalar (non-array) variables are created within the stack frame, which limits them to below 1Mb (except dynamic strings because only the handle is stored on the stack). To create larger ASCIIZ or fixed-length strings, make them GLOBAL or STATIC.


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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Steve Hutchesson]

Following from the technical data that Lance has provided, if you
do use a GLOBAL or STATIC ASCIIZ string, your program will increase
in size by the amount that you allocate that way.

Unless you have a very good reason to do that, I would be inclined
to work with dynamic string or GlobalAlloc() style memory as it
does not blow out the size of your EXE file.

The BYCOPY operator in PowerBASIC allows you to use basic dynamic
string where an API call requires a string address so I would be
inclined to look for another way to do what you are after.

Regards,

[email protected]

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[Peter Scheutz]

Originally posted by Steve Hutchesson:
Following from the technical data that Lance has provided, if you
do use a GLOBAL or STATIC ASCIIZ string, your program will increase
in size by the amount that you allocate that way.

I wanted to test this, so I made the following program:

#Compile Exe
 
Global bigString As Asciiz*16777216
 
Function PbMain()
    MsgBox "HI"
End Function

Steve seems to be correct on this.
Mem usage grows to 17 Mb.
Filesize is 5.0 KB

PS: using any number larger than 16777216, gives a "Integer constant expected" error from the compiler (PB6)


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Best Regards
Peter Scheutz

[This message has been edited by Peter Scheutz (edited August 08, 2001).]

[Semen Matusovski]

It's necessary to make dynamic string.
For most operations (=, Mid$ and so on) long Asciiz are bad, because PB searches 0.

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E-MAIL: [email protected]

[Michael Mattias]

If you want a LOCAL large ASCIIZ string, you can:

FUNCTION Foo

  REDIM szFoo(0) AS ASCIIZ * 2000000

END FUNCTION

For arrays it seems only the descriptor comes out of the stack and the dataspace comes out of the far heap (i.e., the GlobalAlloc family)

MCM