we're going to take some research leeway and investigate the implications of {a}
we're not strangers to doing stuff like that (3d(1))
and we're not strangers to having research prove us wrong
On Wed, 29 Aug 2012 14:49:33 +0200 Cedric Blancher wrote:
> On 29 August 2012 13:54, Roland Mainz <roland.ma...@nrubsig.org> wrote:
> > [Forwarding since AT&T's spam filter is on drugs... ;-(( ]
> > ---------- Forwarded message ----------
> > From: ÏÌØÇÁ ËÒÙÖÁÎÏ×ÓËÁÑ <olga.kryzhanov...@gmail.com>
> > Date: Wed, Aug 29, 2012 at 1:20 PM
> > Subject: Re: [ast-developers] Fwd: Per thread open(), stat(), rename()
> > and so on, and *at() API
> > To: Lionel Cons <lionelcons1...@googlemail.com>
> > Cc: Roland Mainz <roland.ma...@nrubsig.org>, ast-developers@research.att.com
> >
> >
> > Lionel, there are 2 purposes:
> >
> > 1. Allow that ksh93/libshell can be embedded in other applications
> > (Roland calls this 'back end usage', i.e. the user is not aware that
> > he is interacting with a shell, and neither do any other apis know
> > that, or at least should not have to know about that), with out
> > interfering the calling application by changing the current working
> > directory.
> > 2. Allow that ksh93/libshell and the libast api can have a per thread
> > current working directory.
> >
> > There are 2 proposals how to accomplish that:
> > a) Add wrapper functions for open(), stat(), lstat(), chdir(),
> > fchdir(), access(), eaccess(), rename() and so on, and redirect them
> > to their *at() counterparts, with dirfd set to the current threads cwd
> > fd.
> >
> > or
> >
> > b) Add wrapper cpp macros which redirect open(), stat(), lstat(),
> > chdir(), fchdir(), access(), eaccess(), rename() and so on to their
> > *at() counterparts, but define an extra macro which is AT_FDCWD for
> > non threaded applications, and calls a function to obtain the current
> > threads working directory fd for the current thread, but allows to
> > override this macro on a per source file basis, so that applications
> > like libshell, who maintain their own cwd directory fd, can use that.
> >
> > David and Glenn seems to prefer {a}, while I and Roland prefer {b},
> > because {b} will allow an application to work as back end api without
> > interfering with the global cwd or any other, may be libast based apis
> > cwd. This includes nested usage of libshell, like for system() or
> > wordexp().
> I'd prefer option {b}, too. Strongly (sorry David and Glenn :)).
> It sounds like the more sane and flexible way to do this. The big road
> block is that you have to find a solution for old platforms which do
> not have openat() and friends, or EOS (end-of-support) them (I'd
> support that if no platform younger than four years lacks openat() and
> friends).
> Ced
> --
> Cedric Blancher <cedric.blanc...@googlemail.com>
> Institute Pasteur
> _______________________________________________
> ast-developers mailing list
> ast-developers@research.att.com
> https://mailman.research.att.com/mailman/listinfo/ast-developers
_______________________________________________
ast-developers mailing list
ast-developers@research.att.com
https://mailman.research.att.com/mailman/listinfo/ast-developers
