Re: porting from Solaris to Windows 2000

[Jerry van Dijk <jvandyk@attglobal.net>]

                                       
"Terry Westley" <westley@yahoo.com> writes:

[BTW, my news server just came online again, I hope that this is going out)

> In investigating porting a largish Ada application (with lots of Unixy stuff
> like shell scripts, Perl, Tcl/Tk, plus an Oracle database) from Solaris to
> Windows  2000,

Sounds like fun, let me know if you need help.
(seriously, I'm trying to start an Ada/Windows consultancy service :-)

> it appears that I have at least two options:
>
> 1) Cygwin
> 2) MS Interix

> Does anyone have experience with either of these and would like to make a
> recommendation?

Well, Interix before the MS takeover seemed OK, but it's difficult to say
where it will be going in the future.

Cygwin is getting quite nice, e.g. now in 1.3.1 you can use .lnk files as
symbolic links. I have had no real problems using it. And I hear that people
who have the pro version get good support.

On the other hand, it's an extra layer of software that you do not control,
and it does have an performance impact. It also is still under very active
development. And it's not cheap stuff...

>  Are there other possibilities?

Yes. If adding conditional packages to the application is Ok, it's possible
that you can use mingw32 directly. Most Un*x calls can replaced by Win32
calls, esp. if they are already supported by existing Ada packages (POSIX,
Sockets, and such). Assumimg you want to stay compatible with Solaris.
(See for example the december 2000 issue of Dr. Dobbs for a description of the
difficulties encountered in porting a fairly low level C++ application from
Sun to Windows).

Als for perl, tcl/tk, etc. These tools are also available mingw based.
(or Win32 based, as MKS).

As you realise, it's difficult to say anything concrete without knowing the
application in question, and the time and monetary restraints.

Also expect some work in the GUI (tk/tcl ?) part, or take the opertunity to
move to GtkAda.

> We are using GNAT and so I'm also worried about whether there will be any
> adverse interaction between Mingw32 and either of cygwin or Interix.

1. I've used cygwin + GNAT a lot, and using cygwin as the toolkit works
   fine. But don't try to mix compilers or libraries directly :-). But this is
   a temporary situation as cygwin supports an -mingw flag to produce mingw
   executables. Once the unified gcc 3.xx appears, this will not be an issue
   anymore. In the meantime, there are always DLL's :-)

2. It is possible to port GNAT to Interix. Depending on available funding
   you might send a inquiry to ACT.

3. Seriously consider the full mingw option. It will take some more time
   up front, but it might be worth it, especially if the application is
   more widely deployed. It's easy to replace a Tcl/Tk or perl
   implementation, but with cygwin you become dependent on it.

Wishing you a lot of wisdom,
Jerry.

-- 
--  Jerry van Dijk   | email: jvandyk@attglobal.net
--  Leiden, Holland  | web:   home.trouwweb.nl/Jerry