Re: [Mingw-users] CygWin paths in MinGW applications?

[Keith M. <kei...@to...>]

Stefan Bellon wrote:
> I'm developing an application using MinGW which has to handle file
> names. On "normal" Windows everything is fine. But the application
> should work under CygWin as well (i.e. it should be independent of the
> environment, be it Windows or CygWin). But it doesn't cope with paths
> like /cygdrive/c/foo/bar at all. Is there some way to get those paths
> working as well in CygWin?

Well, a path like `/cygdrive/c/foo/bar' is unlikely to work anywhere
*but* in Cygwin.  Thus, if you are running your application in any
any other environment, you should *never* see any such Cygwin specific
path.  This implies that you must ensure that you do not hard code any
such path within the application itself, for that is really the only
way that it is likely to show up at run time, in a non-Cygwin env.

FWIW, this is precisely why I recommend configuring applications in
MSYS, with `--prefix=`cd /install/root; pwd -W', which ensures that
the MSYS specific `/install/root' is passed through to the build
process as a *native* Woe32 path -- there are some applications
which encode, e.g.

  #define APPLICATION_ROOT  "@prefix@"

in a `configure' generated header; if that is translated as the MSYS
specific path, in a standard MinGW application, (i.e. *not* linked
with msys-1.0.dll), then it *will* fail at run time.

If you are developing in Cygwin, and creating MinGW apps, then you
could use `cygpath' to achieve a similar effect; the goal is to ensure
that only native Woe32 paths are seen by the application, at run time.

OTOH, if your goal is to run the MinGW application under Cygwin, yet
allow the user to pass Cygwin paths as command line arguments, then
you probably need to follow Tor Lillqvist's advice:

> Well, you would have to write a function that recognizes Cygwin paths
> and converts them to Win32 paths. Shouldn't be that hard. Beware *not*
> to look at Cygwin's (GPL) source code when you do it.

(Of course, that caveat doesn't apply, if your own application, and any
 derivative work, will be published under a GPL compatible license, but
 it is important, if you were to consider contributing to MinGW itself).

In an ideal world, Cygwin would recognise that it is invoking a native
Woe32 application, and would translate the path names for you, just as
MSYS does.  I don't use Cygwin enough to be sure what provision, if any,
it makes to cope with such issues; this isn't the place to ask -- that
would be on a Cygwin list.

Regards,
Keith.