Re: SIGPIPE not properly reset with 'trap - PIPE'

[Bob Proulx]

Hi Ralf!

Andreas Schwab wrote:
> Ralf Wildenhues writes:
> > I noticed the following bash bug when using gnulib-tool.  The script
> > below outputs
> >
> > foo: line 20: echo: write error: Broken pipe
> > foo: line 21: echo: write error: Broken pipe
> >...
> > Please also note that the above errors occur also when
> >   trap '' PIPE
> > is used instead of 'trap - PIPE'.
> 
> You probably have SIGPIPE ignored when you start the script.  From
> POSIX:
>     Signals that were ignored on entry to a non-interactive shell cannot
>     be trapped or reset, although no error need be reported when
>     attempting to do so.

This sounds very familiar...  Are you suffering from this bug?

  http://lists.gnu.org/archive/html/bug-coreutils/2007-11/msg00154.html

There Jim Meyering wrote (abbreviated):
> I've tracked it down.
> mingetty exec's /bin/login, which calls pam stuff, which in turn uses
> libdbus.  And that is the culprit:
> 
> ./dbus/dbus-sysdeps-unix.c-_dbus_disable_sigpipe (void)
> ./dbus/dbus-sysdeps-unix.c-{
> ./dbus/dbus-sysdeps-unix.c:  signal (SIGPIPE, SIG_IGN);
> ./dbus/dbus-sysdeps-unix.c-}

Bob