#include <signal.h>

int sigaction(int signum, 
              const struct sigaction *restrict act,
              struct sigaction *restrict oldact);

struct sigaction {
    void     (*sa_handler)(int);
    void     (*sa_sigaction)(int, siginfo_t *, void *);
    sigset_t   sa_mask;
    int        sa_flags;
    void     (*sa_restorer)(void);
};

#include <sys/param.h>
#include <rpc/types.h>
#include <strings.h>
#include <time.h>
#include <signal.h>


static void alarmHandler(int signal)
{
   printf("function alarmHandler\n");
}

int main() {

    struct sigaction sa;

    sa.sa_handler = alarmHandler;
    sa.sa_flags = 0;

    if(sigaction(SIGALRM, &sa, NULL)) {
        printf("Error: sigaction!");
    }
    alarm(1);

    sleep(10); // 延时以便触发 SIGALRM 信号后，输出alarmHandler函数中的 printf
}