[Unix network programming] chapter5TCP echo server program

chapter5
 5.1 Overview
 5.2 TCP echo server program: main function

•   int main(int argc, char **argv)
•   {
•    int listenfd,connfd;
•    pid_t childpid;
•    socket_t clilen;
•    struct sockaddr_in, cliaddr, servaddr;
•    listenfd = Socket (AF_INET, SOCK_STREAM, 0);
•    bzero(&servaddr, sizeof(servaddr));
•    servaddr.sin_famlily = AF + INET;
•    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
•    servaddr.sin_port = htons(SERV_PORT);
•    Bind(listenfd, (SA*)&servaddr, sizeof(servaddr));
•    Listne(listenfd,LISTENQ);
•    for(;;)
•    {
•     client = sizeof(cliaddr);
•     connfd = Accept(listenfd, (SA*)&cliaddr, &client);
•     if( (childpit = Fork()) == 0)
•     {
•      Close(listenfd);
•      str_echo(connfd);
•      exit(0);
•     }
•     Close(connfd);
•    }
•   }

 5.3 TCP echo server program: str_echo function

•   void str_echo(int sockfd)
•   {
•    ssize_t n;
•    char buf[MAXLINE];
•   again:
•    while( (n = read(sockfd, buf, MAXLINE)) > 0)
•     Writen(sockfd,buf, n);
•    if(n < 0 && error =- EINTR)
•     goto again;
•    else if(n < 0)
•     err_sys("error");
•   }

 5.4 TCP echo client program: main function
 5.5
 5.6 Normal startup
 5.7 Normal termination
 5.8 POSIX signal
 5.9 Handling SIGCHILD signal
 5.10 wait and waitpid functions

•   #include <sys/wait.h>
•   pid_t wait(int *status);
•   pid_t waitpid(pit_t pid, int *status, int options);