首先创建两个管道：p1,p2

lkmao@ubuntu:/big/libevent/libevent-2.1.12-stable/_install/learn$ mkfifo p1 p2
lkmao@ubuntu:/big/libevent/libevent-2.1.12-stable/_install/learn$ ls -lshF p1 p2
0 prw-rw-r-- 1 lkmao lkmao 0 6月  29 20:39 p1|
0 prw-rw-r-- 1 lkmao lkmao 0 6月  29 20:39 p2|
lkmao@ubuntu:/big/libevent/libevent-2.1.12-stable/_install/learn$

看到p1和p2名字后面都有一根竖线，这是参数-F的作用，表示这两个文件是管道文件。

 测试代码：

#include <sys/types.h>
#include <event2/event-config.h>
#include <stdio.h>
#include <event.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <string.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>

#define _DEBUG_INFO
#ifdef _DEBUG_INFO
#define DEBUG_INFO(format, ...) printf("%s:%d $$ " format "\n" \
,__func__,__LINE__ \
, ##__VA_ARGS__)
#else
#define DEBUG_INFO(format, ...)
#endif

struct private_data{
    struct event ev;
    char buffer[1024];
};

struct event_base *base = NULL;
void stdin_callback(int fd, short event, void *argc)
{
    struct private_data *p = (struct private_data *)argc;    
    memset(p->buffer, 0, sizeof(p->buffer));
    int res = read(fd,p->buffer,sizeof(p->buffer));
    DEBUG_INFO("res = %d",res);
    if(res == 0){
        close(fd);
        free(p);
    }else{
         DEBUG_INFO("read = %d,buffer = %s",fd,p->buffer);
        event_add(&p->ev, NULL);
    }
   
}

void* add_fd_thread(void *arg){
    int i = 0;
    int fd = 0;
    char **argv = (char**)arg;
    while(base == NULL){
        sleep(1);
    }
    for(int i = 1; i < 3;i++){
        fd = open(argv[i],O_RDONLY);
        if(fd < 0){
            perror("open");
            exit(-1);
        }
        DEBUG_INFO("open %s ok",argv[i]);
        struct private_data *p = malloc(sizeof(struct private_data));
        event_set(&p->ev, fd, EV_READ, stdin_callback,p);
        event_base_set(base, &p->ev);
        event_add(&p->ev, NULL);
    }
    DEBUG_INFO("open all file");
    return NULL;
}
static void
signal_cb(evutil_socket_t sig, short events, void *user_data)
{
	struct event_base *base = user_data;
	struct timeval delay = { 2, 0 };

	printf("Caught an interrupt signal; exiting cleanly in two seconds.\n");

	event_base_loopexit(base, &delay);
}
void *run_thread(void *arg){
    int res = 0;
    struct event *signal_event;
    base = event_init();
    signal_event = evsignal_new(base, SIGINT, signal_cb, (void *)base);
    if (!signal_event || event_add(signal_event, NULL)<0) {
		fprintf(stderr, "Could not create/add a signal event!\n");
		return NULL;
	}
    DEBUG_INFO("start");
    do{
        res = event_base_dispatch(base);
        if(res < 0){
            perror("event_base_dispatch");
            DEBUG_INFO("res = %d", res);
            exit(-1);
        }
        DEBUG_INFO("res = %d",res);
    }while(0);
    event_free(signal_event);
	event_base_free(base);
    base = NULL;
    DEBUG_INFO("end");
    return NULL;
}

int main(int argc,char *argv[])
{
    pthread_t t1,t2;
    int res = 0;
    DEBUG_INFO("pid = %d",getpid());
    if(argc < 3){
        DEBUG_INFO("Usage:%s p1 p2",argv[0]);
        return -1;
    }
    res = pthread_create(&t1,NULL,add_fd_thread,argv);
    if(res < 0){
        perror("1:pthread_create");
        return -1;
    }
    res = pthread_create(&t2,NULL,run_thread,NULL);
    if(res < 0){
        perror("2:pthread_create");
        return -1;
    }
    sleep(1);
    while(1){
        sleep(1);
        if(base == NULL){
            break;
        }
    }
    DEBUG_INFO("bye bye");
    return 0;    
}

运行代码：

./_build_/app p1 p2

测试第一个管道

 测试第二个管道

 测试结束

小结