TCP服务器，实现client发送消息，server接收消息

static void usage(const char *proc)
{
 printf("Usage: %s [ip] [port]\n",proc);
}

void *thread_run(void *arg)
{
 printf("create a new thread\n");
 int fd=(int)arg;
 char buf[1024];
 while(1){
  memset(buf,‘\0‘,sizeof(buf));
  ssize_t _s=read(fd,buf,sizeof(buf)-1);
  if(_s>0){
   buf[_s]=‘\0‘;
   printf("client# %s\n",buf);
   write(fd,buf,strlen(buf));
  }else if(_s==0){
   printf("client close...\n");
   break;
  }else{
   printf("read error...\n");
   break;
  }
 }
 return(void *)0;
}

int main(int argc,char *argv[])
{
 if(argc!=3){
  usage(argv[0]);
  exit(1);
 }

//1. creat sock
 int listen_sock=socket(AF_INET,SOCK_STREAM,0);
 if(listen_sock<0){
  perror("socket");
  return 1;
 }

struct sockaddr_in local;
 local.sin_family=AF_INET;
 local.sin_port=htons(atoi(argv[2])); //端口号
 local.sin_addr.s_addr=inet_addr(argv[1]); //IP地址

//2. bind
 if(bind(listen_sock,(struct sockaddr*)&local,sizeof(local))<0){
  perror("bind");
  return 2;
 }

//3. listen
 listen(listen_sock,5);

//4. accept
 struct sockaddr_in peer;
 socklen_t len=sizeof(peer);
 while(1){
 int fd=accept(listen_sock,(struct sockaddr*)&peer,&len);
 if(fd<0){
  perror("accept");
  return 3;
 }
 printf("get a new link,socket -> %s:&d\n",inet_ntoa(peer.sin_addr),ntohs(peer.sin_port));

pthread_t id;
 pthread_create(&id,NULL,thread_run,(void*)fd);

pthread_detach(id);
 }
 return 0;
}

static void usage(const char *proc)
{
 printf("Usage: %s [ip] [port]\n",proc);
}

int main(int argc,char *argv[])
{
 if(argc!=3){
  usage(argv[0]);
  exit(1);
 }
 int sock=socket(AF_INET,SOCK_STREAM,0);
 if(sock<0){
  perror("socket");
  return 2;
 }

struct sockaddr_in remote;
 remote.sin_family=AF_INET;
 remote.sin_port=htons(atoi(argv[2])); //argv[2]
 remote.sin_addr.s_addr=inet_addr(argv[1]);//argv[1]

if(connect(sock,(struct sockaddr*)&remote,sizeof(remote))<0){
  perror("connect");
  return 3;
 }

char buf[1024];
 while(1){
  memset(buf,‘\0‘,sizeof(buf));
  printf("please Enter: ");
  fflush(stdout);
  ssize_t _s=read(0,buf,sizeof(buf)-1);
  if(_s>0){
   buf[_s-1]=‘\0‘;
   write(sock,buf,strlen(buf));
   _s=read(sock,buf,sizeof(buf));
   if(_s>0){
    buf[_s]=‘\0‘;
    printf("%s\n",buf);
   }
  }
 }
 return 0;
}