"UNIX Network Programming," Chapter 1 - an easy time acquiring a client / server program

The program for the "UNIX Network Programming" in the first chapter of the first volume appeared in the program, the program after I test.

Operating System: CentOS 7

Compiler: GCC

Time acquired server program as follows:

 

#include        <sys/types.h>
#include        <sys/socket.h>
#include        <arpa/inet.h>
#include        <unistd.h>
#include        <time.h>
#define  MAX    1024

int main(int argc, char **argv)
{
        int                     listenfd, connfd;
        struct sockaddr_in      servaddr;
        char                    buff[MAX];
        time_t                  ticks;

        if((listenfd = socket(AF_INET, SOCK_STREAM, 0))<0)
        {
                perror("socket fail");
                return 1;
        }
        bzero(&servaddr, sizeof(servaddr));
        servaddr.sin_family      = AF_INET;
        servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
        servaddr.sin_port        = htons(13);   /* daytime server */

        bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));

        listen(listenfd, 10);

        while(1) 
        {
                connfd = accept(listenfd, (struct sockaddr *) NULL, NULL);
                ticks = time(NULL);
                snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks));
                write(connfd, buff, strlen(buff));

                close(connfd);
        }
        return 0;
}

Time acquired client program as follows:

 

#include        <sys/types.h>
#include        <sys/socket.h>
#include        <unistd.h>
#include        <arpa/inet.h>
#include        <stdio.h>

#define PORT    13
#define MAXLINE 1024
int main(int argc, char **argv)
{
        int                     sockfd, n;
        char                    recvline[MAXLINE + 1];
        struct sockaddr_in      servaddr;

        if (argc != 2)
                puts("usage: t.out <IPaddress>");

        if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
                perror("socket error");

        bzero(&servaddr, sizeof(servaddr));
        servaddr.sin_family = AF_INET;
        servaddr.sin_port   = htons(PORT);
        if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0)
                printf("inet_pton error for %s", argv[1]);

        if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0)
                perror("connect error");

        while ( (n = read(sockfd, recvline, MAXLINE)) > 0) 
        {             
                recvline[n] = 0;
                if (fputs(recvline, stdout) == EOF)
                perror("fputs error");
        }
        if (n < 0)
                perror("read error");

        exit(0);
}

Compile server program:

[root@mylinux 1]# gcc -o time_s time_s.c

Compile the client program:

[root@mylinux 1]# gcc -o t.out time_c.c

Next First run the server program:

[root@mylinux 1]# ./time_s

Then run the client program, get the time returned by the server:

[root@mylinux 1]# ./t.out 127.0.0.1
Sat Sep 10 09:36:03 2016