sleep (/bin/sleep) isn't built-in to /bin/sh, so my guess is that /bin/sleep is catching signal. I think that the 2nd version works because when you have a loop in sh and sleep for 1 second and there is time for /bin/sh to catch the signal.
This could be tested by modifying /bin/sleep to catch SIGHUP, printing a response in the handler and running the first script you posted. I could be totally wrong, but that's what I'm guessing. On Thu, Aug 20, 2015 at 5:36 PM, J. Lewis Muir <jlm...@imca-cat.org> wrote: > Hello, NetBSD Users! > > I can't get /bin/sh to trap the SIGHUP signal on amd64 NetBSD > 6.1_STABLE. Does anyone know why? > > Here's a test program exhibiting the behavior: > > === test-program === > #!/bin/sh > > trap 'echo SIGHUP; exit 1' 1 > > sleep 3600 & > wait > ==================== > > I start the test program in one terminal like this: > > $ ./test-program > > And then in another terminal, I find the process ID, 354 in this case, > and send it the SIGHUP signal: > > $ kill -1 354 > > Nothing happens; test-program continues running. > > If I replace running sleep in the background and waiting with the > following: > > === test-program-mod === > #!/bin/sh > > trap 'echo SIGHUP; exit 1' 1 > > while true; do > sleep 1 > done > ======================== > > It responds to a SIGHUP and exits. > > So, is something wrong with the wait command in /bin/sh? > > Thank you! > > Lewis
