[vox-tech] quick, stupid bash question
Peter Jay Salzman
vox-tech@lists.lugod.org
Wed, 29 May 2002 14:40:25 -0700
begin msimons@moria.simons-clan.com <msimons@moria.simons-clan.com>
> On Wed, May 29, 2002 at 03:18:08PM -0400, msimons@moria.simons-clan.com wrote:
> > On Wed, May 29, 2002 at 11:29:29AM -0700, Peter Jay Salzman wrote:
> > > begin nbs <nbs@sonic.net>
> > > > strace lsof 2>&1 1> /dev/null | grep
> > >
> > > ok, haven't tried this, but this looks to me like:
> > >
> > > put stderr into stdout
> > > redirect stdout (and therefore stderr) into /dev/null
> > > pipe stdout (which should be null) to grep.
> >
> > The order of operation of file operators is right to left.
>
> On Wed, May 29, 2002 at 12:32:45PM -0700, Shawn P. Neugebauer wrote:
> > The order of redirects is left to right.
>
> Based on Shawn's comment I've done some tests and operation is very
> much left to right like he says. Now I have a better understanding of
> how dup2 works... but I hope I really don't need to use this anytime
> soon.
(snip)
this was a very valuable thread -- i'm very glad i asked the question
and even more glad people riffed with the theme.
but the actual answer is completely unacceptable.
i can't believe that this is so complicated under bash! i really wish
that the bash developers would so something like:
strace foo 2| grep bar
i see this as a bash deficiency. :(
but it _was_ a great lesson!
pete