Plan 9 from Bell Labs’s /usr/web/sources/contrib/anothy/src/lib/djb-ape/sig/trysgprm.c
#include <signal.h> main() { sigset_t ss; sigemptyset(&ss); sigaddset(&ss,SIGCHLD); sigprocmask(SIG_SETMASK,&ss,(sigset_t *) 0); }