/*next*/
Allgmeines Kommunikationsbeispiel mit Threads
=============================================

Headerfile fuer Server und Client:
----------------------------------
/* inet.h  */

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define SERV_TCP_PORT 8002
#define SERV_HOST_ADDR "141.20.20.139"

#define MAXLINE 512


Client-Programm mit Sockets:
----------------------------

/* c_sock.c - client for tcp-socket */
#include "inet.h"
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
pthread_t       threadread, threadwrite;
/* read from 0, write to socket */

void *talkread(sockfd)
int *sockfd;
{
   int n;
   char sendline[MAXLINE];
   while (write(1,"c: ",3),(n=read(0,sendline,
                                MAXLINE)) > 0) {
      if (write(*sockfd,sendline,n) != n) break;
   }
   pthread_cancel(threadwrite);
}
/*next*/
/* read from socket, write to 1 */
void *talkwrite(sockfd)
int *sockfd;
{
   int n;
   char sendline[MAXLINE];
   while (1) {
      if ((n=read(*sockfd,sendline,MAXLINE)) 
                                  <= 0) break;
      write(1,"\n",1);
      write(1,sendline,n);
      write(1,"C: ",3);
   }
   pthread_cancel(threadread);
}

main(argc,argv)
int argc;
char *argv[];
{
   int sockfd;
   struct sockaddr_in serv_addr;
   pthread_t       thread1, thread2;

   bzero((char *)&serv_addr,sizeof(serv_addr));
   serv_addr.sin_family = AF_INET;
   serv_addr.sin_port = htons(SERV_TCP_PORT);
   serv_addr.sin_addr.s_addr = 
                     inet_addr(SERV_HOST_ADDR);
   if((sockfd=socket(AF_INET,SOCK_STREAM,0))<0){
      fprintf(stderr,
           "c_sock: can't open stream socket\n");
      exit(-1);
   }
/*next*/
   if (connect(sockfd,
               (struct sockaddr *) &serv_addr,
                        sizeof(serv_addr)) < 0) {
      fprintf(stderr,
            "c_sock: can't connect to server\n");
      exit(-2);
   }
  pthread_create(&threadread, NULL,
                 (void *) talkread, (void *) &sockfd); 
  pthread_create(&threadwrite, NULL,
                 (void *) talkwrite, (void *) &sockfd); 

   pthread_join(threadread, NULL);
   write(1,"main read\n",10);
   pthread_join(threadwrite, NULL);
   write(1,"\nconnection down\n",17);
   exit(0);
}
/*next*/
Server-Programm (1.Variante):
-----------------------------
/* s_sock1.c  - Server for tcp-socket */
#include "inet.h"
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
pthread_t       threadread, threadwrite;
/* read from 0 and write to socket */
void *talkread(sockfd)
int *sockfd;
{ 
   int n;
   char sendline[MAXLINE];
   while (write(1,"s: ",3),(n=read(0,sendline,
                      MAXLINE)) > 0) {
      if (write(*sockfd,sendline,n)!=n)break;
   }
   pthread_cancel(threadwrite);
   n=0;
   pthread_exit(&n);
}
/* write to 1 and read from socket */
void *talkwrite(sockfd)
int *sockfd;
{ 
   int n;
   char sendline[MAXLINE];
   while (1) {
           if ((n=read(*sockfd,sendline,MAXLINE))
                               <= 0) break;
           write(1,"\n",1);
           write(1,sendline,n);
           write(1,"S: ",3);
    }
   pthread_cancel(threadread);
   n=0;
   pthread_exit(&n);
}
/*next*/
main(argc,argv)
int argc;
char *argv[];
{
   int sockfd, newsockfd, clilen, childpid;
   struct sockaddr_in  cli_addr, serv_addr;
        int i;

   if ((sockfd=socket(AF_INET,SOCK_STREAM,0))<0){
      fprintf(stderr,
          "server: can't open stream socket\n");
      exit(-1);
        }
   bzero((char *)&serv_addr,sizeof(serv_addr));
   serv_addr.sin_family = AF_INET;
   serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); 
                  /* or your own address */
   serv_addr.sin_port = htons(SERV_TCP_PORT);
   if ((i=bind(sockfd, (struct sockaddr *) &serv_addr,
                        sizeof(serv_addr))) < 0){
    fprintf(stderr, "server: can't bind local address: %d\n",i);
    exit(-2);
   }
   listen(sockfd,5);
   for (;;) {
      clilen = sizeof(cli_addr);
      newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
      if  (newsockfd < 0){
        fprintf(stderr,"server: accept error\n");
        exit(-3);
      }
      pthread_create(&threadread, NULL,
                     (void *) talkread, (void *) &newsockfd);
      pthread_create(&threadwrite, NULL,
                     (void *) talkwrite, (void *) &newsockfd);
      pthread_join(threadread, NULL);
      pthread_join(threadwrite, NULL);
      write(1,"\nconnection down\n",17);
      close(newsockfd);
   }
}
/*next*/
Server-Programm (2.Variante):
-----------------------------

/* s_sock2.c  - Server for tcp-socket */
#include "inet.h"
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
pthread_t       threadread, threadwrite, threadwait;

/* wait for child */
void *waitchild(pid)
int *pid;
{
   wait(NULL);
}

/* read from 0 and write to socket */
void *talkread(sockfd)
int *sockfd;
{ 
   int n;
   char sendline[MAXLINE];

   while (write(1,"s: ",3),(n=read(0,sendline,
                                MAXLINE)) > 0) {
      if (write(*sockfd,sendline,n) !=n) break;
   }
   pthread_cancel(threadwrite);
}
/*next*/
/* write to 1 and read from socket */
void *talkwrite(sockfd)
int *sockfd;
{ 
   int n;
   char sendline[MAXLINE];

   while (1) {
           if ((n=read(*sockfd,sendline,
                       MAXLINE)) <= 0) break;
           write(1,"\n",1);
           write(1,sendline,n);
           write(1,"S: ",3);
    }
   pthread_cancel(threadread);
}

main(argc,argv)
int argc; char *argv[];
{
   int sockfd, newsockfd, clilen, childpid;
   struct sockaddr_in  cli_addr, serv_addr;
        int i;

   if ((sockfd=socket(AF_INET,SOCK_STREAM,0))<0){
      fprintf(stderr,
         "server: can't open stream socket\n");
      exit(-1);
   }
   bzero((char *) &serv_addr, sizeof(serv_addr));
   serv_addr.sin_family = AF_INET;
   serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); 
                  /* or your own address */
   serv_addr.sin_port = htons(SERV_TCP_PORT);
   if ((i=bind(sockfd, (struct sockaddr *) &serv_addr,
                        sizeof(serv_addr))) < 0){
    fprintf(stderr, "server: can't bind local address: %d\n",i);
    exit(-2);
   }
/*next*/
   listen(sockfd,5);

   for (;;) {
      clilen = sizeof(cli_addr);
      newsockfd = accept(sockfd,
          (struct sockaddr *)&cli_addr, &clilen);
      if  (newsockfd < 0){
        fprintf(stderr,"server: accept error\n");
         exit(-3);
      }
      if ((childpid = fork()) < 0) {
         fprintf(stderr,"server: fork error\n");
         exit(-4);
      }

      else if (childpid == 0) {
              close(sockfd);
              pthread_create(&threadread,
#ifdef DEC
                          pthread_attr_default,
#else
                          NULL,
#endif
                          (void *) talkread,
                          (void *) &newsockfd);
              pthread_create(&threadwrite,
#ifdef DEC
                          pthread_attr_default,
#else
                          NULL,
#endif
                          (void *) talkwrite,
                          (void *) &newsockfd);

              pthread_join(threadread, NULL);
              pthread_join(threadwrite, NULL);
              write(1,"\nconnection down\n",17);
              exit(0);
           }
      close(newsockfd);
      pthread_create(&threadwait,
#ifdef DEC
                          pthread_attr_default,
#else
                          NULL,
#endif
                          (void *) waitchild,
                          (void *) &childpid);
   }
}