#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/utsname.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <netdb.h>#include <unistd.h>#include <fcntl.h>#define bufsize 255#define namesize 20int tcpSocket(){  int n;  if ( (n = socket(PF_INET,SOCK_STREAM,0))==-1)  {    perror("TCP Socket error");    exit(1);  }  return(n);}void Setsockopt(int s){  int on = 1;  struct linger linger = { 0 };  linger.l_onoff = 1;  linger.l_linger = 30;  if ( setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *) &on, sizeof(on))==-1)  {    perror("Setsockopt(...,SO_REUSEADDR,...)");    exit(1);  }  if ( setsockopt(s, SOL_SOCKET, SO_LINGER, (const char *) &linger, sizeof(linger))==-1)  {    perror("Setsockopt(...,SO_LINGER,...)");    exit(1);  }}int Bind(int sockfd, const struct sockaddr *my_addr, socklen_t addrlen){  return bind(sockfd,my_addr,addrlen);}void Listen(int s){  if (-1 == listen(s,5))  {    perror("Listen()");    exit(1);  }}int Accept(int s, struct sockaddr *addr, socklen_t *addrlen){  int newSocket;  if ((newSocket=accept(s, addr, addrlen))==-1)  {    perror("Accept()");    exit(1);  }  return newSocket;}void Connect(int  sockfd,  const  struct sockaddr *sock_addr){  if (-1 == connect(sockfd, sock_addr, sizeof(*sock_addr)))  {    printf("Server haven't started\n");    exit(1);  }}void GetHostName(char *buffer, int length){  struct utsname sysname = { 0 };  int status = 0;  status = uname(&sysname);  if (-1 != status)  {    strncpy(buffer, sysname.nodename, length);  }  else  {    perror("GetHostName()");    exit(1);  }}void CreateSockAddr(const char *hostname,struct sockaddr_in *sockaddress,int port){  struct hostent *host = NULL;  host = gethostbyname(hostname);  if (NULL == host)  {    host = gethostbyaddr(hostname,                         strlen(hostname), AF_INET);    if (NULL == host)    {      perror("Error resolving server address");      exit(1);    }  }  (void) memset(sockaddress, 0, sizeof(sockaddress));  (void) memcpy(&((*sockaddress).sin_addr), host->h_addr, host->h_length);  sockaddress->sin_addr.s_addr=htonl(INADDR_ANY);  sockaddress->sin_family = AF_INET;  sockaddress->sin_port = htons(port);}ssize_t Send(int s, const void *buf){  ssize_t sendn;  if( -1==(sendn=send(s, buf, strlen(buf), 0)))  {    perror("Send()");    close(s);  }  return sendn;}ssize_t Recv(int s, void *buf){  ssize_t recvn;  if( -1==(recvn= recv(s, buf, bufsize, 0)))  {    perror("Recv()");    close(s);  }  return recvn;}char *Fgets(char *s){  bzero(s,bufsize);  if(fgets(s,bufsize,stdin)==NULL)  {    perror("Fgets()");    exit(1);  }  return s;}void Rtrim(char *buf){  int i;  for(i=0;i<255;i++)  {    if(buf[i]=='\n')    {      buf[i]=0;      break;    }  }}