I'm trying to verify my understanding of the signal specifications. On the signal.h man page SA_RESETHAND is defined as: Causes signal dispositions to be set to SIG_DFL on entry to signal handlers On the sigaction() man page action of SA_RESETHAND is defined: If set, the disposition of the signal shall be reset to SIG_DFL and the SA_SIGINFO flag shall be cleared on entry to the signal handler.
My questions are: 1) When using a signal handler defined by sa_handler should signal(2) return SIG_DFL for the old signal value? 2) When using a signal handler defined by sa_handler or sa_sigaction should the signal handler value returned in oact by the call sigaction(sig, NULL, &oact) be set to SIG_DFL? 3) When using a handler defined by sa_sigaction should the sa_flags value returned in oact by the call: sigaction(sig, NULL, &oact) not have SA_SIGINFO set? My tests on different versions of UNIX indicate 1) SIG_DFL is not always set on entry to signal handlers when the SA_RESETHAND flag is set via sigaction(2) 2) The SA_SIGINFO flag is not cleared when returned by sigaction(2) when used in the signal handler. Thank you for clarifying my understanding of the specification.
