HELP! - why does this process die?

[Dave Lennert]

>      The problem is that because shell C exits, it leaves D in the background
> without a parent. Any process without a parent that receives the signal
> SIGTSTP (which is what a <ctrl>-Z sends), or the signal SIGTTIN or SIGTTOU,
> is silently killed by the kernel with a SIGKILL, which is why you can't trap
> it.

Technically, any process without a parent (orphaned to init) that *stops*
as a result of receiving SIGTSTP, SIGTTIN, or SIGTTOU is sent SIGKILL.
(SIGSTOP does not have this side effect.)

An application can become immune to this side effect (the SIGKILL) by
catching, ignoring, or masking SIGTSTP, SIGTTIN, and SIGTTOU.  This
will also prevent the application from being stopped by these signals.

    Dave Lennert                ucbvax!hpda!davel               [UUCP]
    Hewlett-Packard - 47UX      ihnp4!hplabs!hpda!davel         [UUCP]
    19447 Pruneridge Ave.       hpda!davel at Berkeley.edu         [ARPA]
    Cupertino, CA  95014        (408) 447-6325                  [AT&T]