otherwise cause no action: SIGUSR1, SIGUSR2, SIGPIPE, SIGALRM,
SIGCHLD, SIGCONT, SIGURG, SIGXCPU, SIGXFSZ, SIGVTALRM, SIGWINCH,
SIGIO, SIGPWR, SIGINFO, SIGTHR, SIGWAITING, SIGLWP, SIGFREEZE,
SIGTHAW, SIGLOST, SIGXRES, SIGJVM1, SIGJVM2, and any real time signals
used on the system. Note that not all of these signals are available
on all systems.