struct siginfo {
int si_signo; /* signal number */
int si_errno; /* if nonzero, errno value from <errno.h> */
int si_code; /* additional info (depends on signal) */
pid_t si_pid; /* sending process ID */
uid_t si_uid; /* sending process real user ID */
void *si_addr; /* address that caused the fault */
int si_status; /* exit value or signal number */
long si_band; /* band number for SIGPOLL */
/* possibly other fields also */
};
我不明白si_band
。什麼是SIGPOLL的樂隊號碼?