tcp

服务器：tcpsrv.c

#include<stdio.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<netinet/ip.h>
#include<strings.h>
#include<string.h>
#include<arpa/inet.h>

static int connfd;

int main(int argc, char **argv)
{
 int sockfd;
 sockfd = socket(AF_INET, SOCK_STREAM, 0);

 int on = 1;
 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);

 struct sockaddr_in my_addr, cli_addr;
 bzero(&my_addr, sizeof my_addr);
 my_addr.sin_family = AF_INET;
 my_addr.sin_port = htons(atoi(argv[1]));
 my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
 bind(sockfd, (struct sockaddr *)&my_addr, sizeof(my_addr));

 listen(sockfd, 4);

 socklen_t len;
 len = sizeof(cli_addr);
 bzero(&cli_addr, len);
 connfd = accept(sockfd, (struct sockaddr *)&cli_addr, &len);

 printf("new connection: %s:%hu\n",inet_ntoa(cli_addr.sin_addr),ntohs(cli_addr.sin_port));

 char buf[1024];
// char b[1024];
 int n;
 while(1){
  bzero(buf, 1024);
//  bzero(b, 1024);
  if((n = read(connfd, buf, 1023)) <= 0)
   break;
  write(connfd, buf, strlen(buf));
  printf("srv: %s\n",buf);
//  fgets(b, 1024, stdin);
//  write(connfd, b, 1023);
 
 }
 return 0;
}

客服端：tcpcli.c

#include<stdio.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<netinet/ip.h>
#include<strings.h>
#include<string.h>

int main(int argc, char **argv)
{
 int sockfd;
 sockfd = socket(AF_INET, SOCK_STREAM, 0);

 struct sockaddr_in src_addr;
 bzero(&src_addr, sizeof src_addr);
 src_addr.sin_family = AF_INET;
 inet_pton(AF_INET, argv[1],(struct sockaddr *)&src_addr.sin_addr);
 src_addr.sin_port = htons(atoi(argv[2]));

 connect(sockfd, (struct sockaddr *)&src_addr, sizeof src_addr);
 
 char buf[1024];
 char b[1024];
 while(1){
  bzero(b, 1024);
  fgets(buf, 1024, stdin);
  write(sockfd, buf, strlen(buf));
  read(sockfd, b ,1023);
  printf("b: %s\n",b);
 }
 return 0;
}