receiver.c

这是一个在局域网下的即时聊天工具, 由于本人是编程初学者, 非常希望从贵站点中得到宝贵的源码资料供我学习和参考, 请站长允许我加入,谢谢!

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <string.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>

#define MY_PORT 9999

main(int argc, char **argv)
{
int sock_fd;
char message[256];
int sin_len;
struct sockaddr_in sin;
ssize_t recv_rc;
long save_file_flags;

printf("Your instant message program is running..\n");

bzero(&sin, sizeof(struct sockaddr_in));
sin.sin_family = AF_INET;
sin.sin_port = htons(MY_PORT);
sin.sin_addr.s_addr = htonl(INADDR_ANY);

sin_len = sizeof(struct sockaddr_in);

if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
 {
 printf("Socket error!\n");
 exit(255);
 }

if (bind(sock_fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in)) < 0)
 {
 printf("Bind error!\n");
 exit(255);
 }

save_file_flags = fcntl(sock_fd, F_GETFL);
//printf("File flags are %ld\n", save_file_flags);
save_file_flags |= O_NONBLOCK;

if (fcntl(sock_fd, F_SETFL, save_file_flags) == -1)
 {
 printf("trying to set socket to non-blocking error!\n");
 exit(255);
 }
//printf("File flags are now %ld\n", save_file_flags);

while(1)
 {
 sleep(1);

 recv_rc = recvfrom(sock_fd, message, sizeof(message), 0, (struct sockaddr *)&sin, &sin_len);

 if (recv_rc == -1 && errno != EAGAIN)
  {
  printf("Received from sender %s error!\n", inet_ntoa(sin.sin_addr));
  exit(255);
  }

 if (recv_rc == 0 | errno == EAGAIN)
  {
  //printf("No data yet\n");
  errno = 0;
  continue;
  }

 errno = 0;

 printf("Get a message from sender %s:\n%s\n", inet_ntoa(sin.sin_addr), message);

 }

if (close(sock_fd) == -1)
 {
 printf("Close file failed.\n");
 exit(255);
 }

exit(0);
}