Re: exit value of intermediate program in pipe

[Sweth Chandramouli <sweth@astaroth.nit.gwu.edu>]

On Sat, May 02, 1998 at 04:24:40PM -0600, Steve Talley wrote:
> I have a function foo:
> 
> foo () {
> 	/bin/blah | grep -v "foo"
> }
> 
> I would like this function to exit with the exit value from the
> /bin/blah process, but it exits with the exit value from grep instead.

	if running /bin/blah isn't very compute-intensive, and doesn't
change its own subsequent input in any way (so that it can be run twice
consecutively with the same results), why not try

foo () {
   /bin/blah > /dev/null ; exitstatus=$?
   /bin/blah | grep -v "bar"
   return $exitstatus
}

	in theory, there should be some cleaner way to do this using
a two-way pipe, but i've never been able to get them to work correctly.
i think there are ways to export the value of a variable out of a code
block, which would also do the trick, but 

{ /bin/blah ; export exitstatus=$? } | grep -v "bar" ; return $exitstatus

, which is how i thought that was done, didn't work.

	-- sweth.

-- 
"Countin' on a remedy I've counted on before
Goin' with a cure that's never failed me
What you call the disease
I call the remedy"  -- The Mighty Mighty Bosstones