Unix网络编程笔记(第四章)

TCP时间服务:

server.c:

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


#define bzero(ptr , n) memset(ptr, 0, n)
#define MAXLINE 4096
#define SA struct sockaddr
#define ENDLESS for( ; ; )   //just for fun...

int
main(int argc ,char** argv)
{
    int  listenfd, connfd;
    socklen_t len;
    struct sockaddr_in servaddr, cliaddr;
    char  buff[MAXLINE];
    time_t ticks;
    
    if(argc != 2){
        fprintf(stderr,"Usage: %s port\n",argv[0]);
        exit(1);
     }
    
    listenfd = socket(AF_INET, SOCK_STREAM, 0);
    
    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(atoi(argv[1]));   //choice the port you like...
    
    bind(listenfd, (SA*)&servaddr, sizeof(servaddr));
    listen(listenfd, 5);
    ENDLESS {
        len = sizeof(cliaddr);
        connfd = accept(listenfd, (SA*)&cliaddr, &len);
        printf("Got connection from %s, port %d\r\n",
                inet_ntop(AF_INET, &cliaddr.sin_addr, buff, sizeof(buff)),
                ntohs(cliaddr.sin_port));
        ticks = time(NULL);
        snprintf(buff, sizeof(buff), "%.24s\r\n",ctime(&ticks));
        write(connfd, buff, strlen(buff));
        close(connfd);
     }

}

client.c:

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

#define bzero(ptr , n) memset(ptr, 0, n)
#define MAXLINE 4096
#define SA struct sockaddr

int main(int argc,char ** argv)
{
	int    sockfd, n;
	char   recvline[MAXLINE];
	struct sockaddr_in servaddr;

	if (argc != 3) {
		fprintf(stderr, " Usage: %s IPAddress,Port ", argv[0]);
		exit(1);
	}

	if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0 ) {
		fprintf(stderr, "socket error\n ");
		exit(1);
	}

	bzero(&servaddr, sizeof(servaddr));
	servaddr.sin_family = AF_INET;
	servaddr.sin_port = htons( atoi(argv[2]) );
	if ( inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0) {
		fprintf(stderr, "inet_pton error for %s ", argv[1]);
		exit(1);
	}

	if( (connect(sockfd, (SA*)&servaddr, sizeof(servaddr))) < 0 ) {
		fprintf(stderr, "connect error\n");
		exit(1);
	}

	while ( (n= read(sockfd,recvline,MAXLINE)) > 0) {
		recvline[n]=0;
		if ( fputs(recvline,stdout) == EOF) {
			fprintf(stderr, "fputs error\n");
			exit(1);
		}
	}

	if(n < 0) {
		fprintf(stderr, "read error\n");
		exit(1);
	}

	exit(0);
 
}

运行结果:

另外一个实例见另一篇文章:

http://blog.youkuaiyun.com/breakback/article/details/7288400