daytimecli.c

SUN Solaris8平台下进程间通信

#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h> 
#include "err_exit.h"    
#define  MAXBUFFSIZE    256
void init_sockaddr(struct sockaddr_in *, const char *, const char *);

int socket_connect(const char *hostname, const char *serv_port)
{
    int sockfd;
    struct sockaddr_in sockaddr;
    struct hostent *hp;
    char *host, myname[104];
    /* 初始服务器的IP地址和端口 */
    init_sockaddr(&sockaddr, hostname, serv_port);
    /* 创建套接字 */
    if ((sockfd = socket(AF_INET,SOCK_STREAM,0)) < 0)
        err_exit("socket error");
    /* 建立与服务的连接 */
    if(connect(sockfd, (struct sockaddr *)&sockaddr,sizeof(sockaddr)) < 0)
        err_exit("connect error");
    return(sockfd);
}

int main(int argc, char **argv)
{
    int sockfd,n;
    char recvbuff[MAXBUFFSIZE], *host;
    struct sockaddr_in servaddr;
    /* 检查参数 */
    if(argc < 2)
        host = NULL;
    else
        host = argv[1];
    /* 创建套接字并建立与服务的连接 */
    sockfd = socket_connect(host,"13");
    /* 读服务的回答并显示结果 */
    while((n = read(sockfd,recvbuff,MAXBUFFSIZE)) > 0){
        recvbuff[n] = 0;    /* 填入终止符 */
        fputs(recvbuff,stdout);
    }
    if(n<0)
        err_exit("read error");
    exit(0);
}

void init_sockaddr(struct sockaddr_in *name, const char *hostname, 
                     const char *serv)
{
    struct hostent *hp;
    char *host,myname[255];
    if (hostname == NULL){
        gethostname(myname, sizeof(myname));
        host = myname;
    }
    else
        host = hostname;
    /* 获取主机地址信息 */
    if ((hp = gethostbyname(host)) == NULL){
        printf("Unknown host: %s\n", host);
        exit(-1);
    }
    /* 填入服务器的IP地址和端口 */
    bzero(name,sizeof(struct sockaddr));
    if (hp->h_addrtype == AF_INET){   
        name->sin_family = AF_INET;
        bcopy(hp->h_addr_list[0], &name->sin_addr, hp->h_length);
        if (serv == NULL)
            name -> sin_port = htons(0);
        else
            name -> sin_port = htons(atoi(serv));
    }
    else {
        printf("Unknown address type\n");
        exit(-1);
    }
}