p12-28.c

SUN Solaris8平台下进程间通信

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <sys/time.h>
#include "err_exit.h"
#define MAXMSG 512
int main(int argc, char **argv) 
{ 
    int sock,n; 
    struct sockaddr_in name; 
    struct hostent *hp;
    char sndmsg[MAXMSG],rcvmsg[MAXMSG];
    struct timeval timev;
    /* 检查参数的合法性 */
    if (argc < 3) {
        fprintf(stderr, "Usage: a.out <hostname> <port>\n");
        exit(1);
    }
    if ((sock = socket(AF_INET, SOCK_DGRAM, 0))< 0) 
        err_exit("opening datagram socket"); 
    /* 形成发送目的地套接字缺省地址 */ 
    init_sockaddr(&name, argv[1], argv[2]);
    /* 设置套接字接收超时选项 */
    timev.tv_sec = 5;
    timev.tv_usec = 0;
    setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &timev, sizeof(timev));
    while(fgets(sndmsg,MAXMSG,stdin) != NULL){
         /* 发送从终端读入的消息 */
        if (sendto(sock, sndmsg, sizeof(sndmsg), 0, &name, sizeof(name)) < 0) 
            perror("(client) sending error");
         /* 接收并显示服务返回的回答,若超时或出错，终止执行 */
        if ((n = read(sock,rcvmsg, MAXMSG, 0, NULL, NULL)) < 0){
            if (errno == EWOULDBLOCK) 
                fprintf(stderr,"socket timeout\n");
            else
                perror("(client) receive error ");
            close(sock);
            exit(1); 
        }
        rcvmsg[n] = 0;
        printf("client received message: %s",rcvmsg);
    }
    close(sock);
    exit(0); 
}