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Subject: DLL's for Dummies
To: cygwin AT cygwin DOT com
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Message-ID: <OF277487F1.DD007F3A-ON85256AFC.004B9C63@ipaper.com>
From: "David Westbury" <David DOT Westbury AT ipaper DOT com>
Date: Tue, 6 Nov 2001 09:30:08 -0500
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 11/06/2001 08:31:05 AM
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I recently got started with Cygwin. What a great package! Coming from a
Unix programming background I'm completely in the dark about DLL's. I need
to write C programs that access a third party API. I'm experimenting with
gcc but having disappointing results. I'm trying to compile and run an
example C program that came with the third party API package. Although I
don't know how to compile a program against a DLL I've found that the gcc
string below results in an error free compile/link. The resulting
executable runs to some degree. Some API calls execute correctly. However
using the gdb debugger it appears that random memory locations are being
modified as I step through the program. The program employs elements of a
structure as arguments to the API calls. The debugger shows that, in
addition to modifying the correct structure elements, random elements of
the structure are also being modified as I step over many of the API calls.
Also memcpy() appears to produce similar memory corruption. I'm hoping this
will ring a bell with someone who can guide me in the right direction.

Here is the gcc string I'm using:

gcc  -g   myprog.c  -o myprog   /path to third party dll/api.dll

I've been working with this for days.  Forgive me if I haven't read the
right FAQ or documentation. I've scanned about everything I can find. Any
help would be greatly appreciated. Thanks.



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