talk_tcp_cl.c

unix/linux使用socket编程的一个具体示例

/*mytalk.c*/
#include <stdio.h>      /*fputs()*/
#include <stdlib.h>     /*exit()*/
#include <string.h>    	/*memset(),atoi()*/
#include <errno.h>      /*strerror()*/

#include <netinet/in.h> /*struct sockaddr_in,htons(),inet_addr()*/
#include <sys/types.h>  /*socket()*/
#include <sys/socket.h> /*socket(),inet_addr()*/
#include <arpa/inet.h>  /*inet_addr()*/

static void
myerr(const char *on_what)
{
  if(errno!=0){
    fputs(strerror(errno),stderr);
    fputs(":",stderr);
  }
  fputs(on_what,stderr);
  fputc('\n',stderr);
  exit(1);
}

extern int read();
extern int write();
extern int close();

int main(int argc,char **argv)
{
  int z; /*state code of back*/
  int s; /*local socket*/
  char *server_ip=NULL;
//  char *client_ip=NULL;
  char *server_port="9095";
//  char *client_port="9096";
  struct sockaddr_in server_address;
//  struct sockaddr_in client_address;
  int len_inet;
//  char receive_buf[512];
  char send_buf[512];
  
  if(argc>=2)server_ip=argv[1];
//  if(argc>=3)client_ip=argv[2];

  
  /*creat server socket address*/
  memset(&server_address,0,sizeof server_address);
  server_address.sin_family=AF_INET;
  server_address.sin_port=htons(atoi(server_port));
  server_address.sin_addr.s_addr=inet_addr(server_ip);
  
  /*generat local socket*/
  s=socket(PF_INET,SOCK_STREAM,0);/*creat a TCP socket*/
  if(s==-1) myerr("socket()");
  len_inet=sizeof server_address;
  
  z=connect(s,(struct sockaddr *)&server_address,len_inet);
  if(z==-1)myerr("connect(2)");
      
  for(;;){
    scanf("%s",send_buf);
   
    z=write(s, send_buf, sizeof send_buf);
    if(z==-1) myerr("write(2)");
  }
  close(s);
  putchar('\n');
  return 0;
}