在linux会用到sigaction函数，这个函数干什么用的呢？ SIGACTION(2) Linux Programmer’s Manual SIGACTION(2)
NAME sigaction, rt_sigaction - examine and change a signal action
SYNOPSIS
#include <signal.h>
int sigaction(
int signum,
const struct sigaction *act,
struct sigaction *oldact);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
sigaction(): _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE
siginfo_t: _POSIX_C_SOURCE >= 199309L
DESCRIPTION
The sigaction() system call is used to change the action taken by a process on receipt of a specific signal. (See signal(7) for an overview of signa
