信号例子

这是根据setjmp/longjmp,sigaction signal，sigqueue函数写的一个对信号这章的大体程序：

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<setjmp.h>
#include<signal.h>
#include<string.h>

jmp_buf buf;

void handler_sigint1(int signo)
{
    printf("recv SIGINT\n");
    longjmp(buf,1);
}
void handler_sigint2(int signum,siginfo_t *info,void *myact)
{
    int i;
    for(i=0;i<5;i++)
        printf("%d\n",*((int *)(info->si_value.sival_ptr)+i));
    printf("handle signal %d over\n",signum);
    longjmp(buf,2);
}
int main(int argc,char **argv)
{
    struct    sigaction act;
    union sigval mysigval;
    int i;
    int sig;
    pid_t pid;
    int data[10];
    memset(data,0,sizeof(data));
    for(i=0;i<5;i++)
        data[i]=2;
    mysigval.sival_ptr=data;
//    sig=atoi(argv[1]);
    pid=getpid();
    sigemptyset(&act.sa_mask);

    switch(setjmp(buf))
    {
        case 0:
            break;
        case 1:
               printf("return from handler_sigint1\n");
               break;
        case 2:
                printf("wait for handler_sigint2\n");
                break;
        default:
               break;
    }
    sig=2;
    signal(SIGINT,handler_sigint1);
    raise(sig);
    act.sa_sigaction=handler_sigint2;
    act.sa_flags=SA_SIGINFO;
    sigaction(SIGRTMIN+15,&act,NULL);
    sig=49;
    sigqueue(pid,sig,mysigval);


    while(1);



    return 0;
}