[Python-checkins] commit of r41662 - in python/trunk: Misc/NEWS Objects/fileobject.c configure configure.in pyconfig.h.in

[Guido van Rossum]

Isn't it expensive to call isatty() on every tell() call? Is it worth
it just to make a unit test pass?

Or is there a real bug caused by tell() lying?

--Guido

On 12/13/05, hyeshik.chang <python-checkins at python.org> wrote:
> Author: hyeshik.chang
> Date: Tue Dec 13 17:44:02 2005
> New Revision: 41662
>
> Modified:
>    python/trunk/Misc/NEWS
>    python/trunk/Objects/fileobject.c
>    python/trunk/configure
>    python/trunk/configure.in
>    python/trunk/pyconfig.h.in
> Log:
> Add a workaround for file.ftell() to raise IOError for ttys.
> ftell(3) on BSD doesn't set errno even for ttys and returns useless
> values.
>
>
> Modified: python/trunk/Misc/NEWS
> ==============================================================================
> --- python/trunk/Misc/NEWS      (original)
> +++ python/trunk/Misc/NEWS      Tue Dec 13 17:44:02 2005
> @@ -12,6 +12,9 @@
>  Core and builtins
>  -----------------
>
> +- Added a workaround for file.tell() to raise IOError when the file
> +  is a tty on every platforms as documented in our library reference.
> +
>  - Patch #1350409: Work around signal handling bug in Visual Studio 2005.
>
>  - Bug #1281408: Py_BuildValue now works correct even with unsigned longs
>
> Modified: python/trunk/Objects/fileobject.c
> ==============================================================================
> --- python/trunk/Objects/fileobject.c   (original)
> +++ python/trunk/Objects/fileobject.c   Tue Dec 13 17:44:02 2005
> @@ -482,6 +482,13 @@
>  static Py_off_t
>  _portable_ftell(FILE* fp)
>  {
> +#ifdef HAVE_BROKEN_FTELL
> +       /* ftell doesn't fail for tty fds on FreeBSD and some others */
> +       if (isatty(fileno(fp))) {
> +               errno = ESPIPE;
> +               return -1;
> +       }
> +#endif
>  #if !defined(HAVE_LARGEFILE_SUPPORT)
>         return ftell(fp);
>  #elif defined(HAVE_FTELLO) && SIZEOF_OFF_T >= 8
>
> Modified: python/trunk/configure
[...]

--
--Guido van Rossum (home page: http://www.python.org/~guido/)