socket网络编程-----I/O复用之select函数

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/select.h>
#include <sys/time.h>


#define BUFSIZE 255

int rw_opt(int rdfd,int wdfd)
{
    int num;
    char buf[BUFSIZE];
    memset(buf,0,sizeof(buf));
    num = read(rdfd,buf,sizeof(buf));
    if(wdfd == 1)
        write(1,">>>",3);
    write(wdfd,buf,num);
    if(strncmp(buf,"quit",4) == 0)
        return 0;
    return num;
}

int main()
{
    int sockfd,ret;
    int acceptfd;
    struct sockaddr_in s_addr;
    sockfd = socket(AF_INET,SOCK_STREAM,0);
    if(sockfd == -1)
    {
        printf("socket error!
");
        return 0;
    }
    
    memset(&s_addr,0,sizeof(struct sockaddr_in));
    s_addr.sin_family = AF_INET;
    s_addr.sin_port = htons(1234);
    s_addr.sin_addr.s_addr = htons(INADDR_ANY);
    ret = bind(sockfd,(struct sockaddr *)&s_addr,sizeof(struct sockaddr_in));
    if(ret == -1)
    {
        printf("bind error!
");
        return 0;
    }

    ret = listen(sockfd,5);
    if(ret == -1)
    {
        printf("listen error!
");
        return 0;
    }

    int addrlen = sizeof(struct sockaddr);
    acceptfd = accept(sockfd,(struct sockaddr *)&s_addr,&addrlen);
    if(acceptfd == -1)
    {
        printf("accept error!
");
    }
    else
    {
        printf("%s-----%d
",inet_ntoa(s_addr.sin_addr),ntohs(s_addr.sin_port));
    }
    
    fd_set rdfds;
    struct timeval timeout;
    timeout.tv_sec = 5;
    timeout.tv_usec = 1000;
    while(1)
    {
        FD_ZERO(&rdfds);
        FD_SET(0,&rdfds);
        FD_SET(acceptfd,&rdfds);
        ret = select(acceptfd+1,&rdfds,NULL,NULL,&timeout);
        if(ret < 0)
        {
            printf("polling Monitor failed!
");
            continue;
        }
        if(FD_ISSET(0,&rdfds))
        {
            ret = rw_opt(0,acceptfd);
            if(ret == 0)
                break;
        }
        if(FD_ISSET(acceptfd,&rdfds))
        {
            ret = rw_opt(acceptfd,1);
            if(ret == 0)
                break;
        }
    }
    close(acceptfd);
    close(sockfd);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/select.h>
#include <sys/time.h>


#define BUFSIZE 255

int rw_opt(int rdfd,int wdfd)
{
    int num;
    char buf[BUFSIZE];
    memset(buf,0,sizeof(buf));
    num = read(rdfd,buf,sizeof(buf));
    if(wdfd == 1)
        write(1,">>>",3);
    write(wdfd,buf,num);
    if(strncmp(buf,"quit",4) == 0)
        return 0;
    return num;
}


int main(int argc,char **argv)
{
    int sockfd,ret;
    int acceptfd;
    struct sockaddr_in s_addr;
    sockfd = socket(AF_INET,SOCK_STREAM,0);
    if(sockfd == -1)
    {
        printf("socket error!
");
        return 0;
    }

    memset(&s_addr,0,sizeof(struct sockaddr_in));
    s_addr.sin_family = AF_INET;
    s_addr.sin_port = htons(1234);
    s_addr.sin_addr.s_addr = inet_addr(argv[1]);
    ret = connect(sockfd,(struct sockaddr *)&s_addr,sizeof(struct sockaddr_in));
    if(ret == -1)
    {
        printf("connect error!
");
        return 0;
    }
    fd_set rdfds;
    struct timeval timeout;
    timeout.tv_sec = 5;
    timeout.tv_usec = 1000;

    while(1)
    {
        FD_ZERO(&rdfds);
        FD_SET(0,&rdfds);
        FD_SET(sockfd,&rdfds);
        ret = select(sockfd+1,&rdfds,NULL,NULL,&timeout);
        if(ret < 0)
        {
            printf("polling Monitor failed!
");
            continue;
        }
        if(FD_ISSET(0,&rdfds))
        {
            ret = rw_opt(0,sockfd);
            if(ret == 0)
                break;
        }
        if(FD_ISSET(sockfd,&rdfds))
        {
            ret = rw_opt(sockfd,1);
            if(ret == 0)
                break;
        }

    }
    close(sockfd);
    return 0;
}