udp_cli.c

   1 #include <sys/types.h>
   2 #include <sys/socket.h>
   3 #include <string.h>
   4 #include <netinet/in.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <arpa/inet.h>
   8 #include <unistd.h>
   9
  10 #define MAXLINE 1024
  11 #define SERV_PORT 4000
  12
  13 void do_cli(FILE *fp, int sockfd, struct sockaddr *pservaddr, socklen_t servlen)
  14 {
  15         int n;
  16         char sendline[MAXLINE], recvline[MAXLINE + 1];
  17
  18
  19         if(connect(sockfd, (struct sockaddr *)pservaddr, servlen) == -1)
  20         {
  21                 perror("connect error");
  22                 exit(1);
  23         }
  24         else
  25         {
  26                 printf("connect OK\n");
  27         }
  28
  29         fgets(sendline, MAXLINE, fp);
  30         n = write(sockfd, sendline, strlen(sendline)-1);
  31         if ( n <= 0)
  32                 perror("write error\n");
  33         printf("write %s \n",sendline);
  34
  35 }
  36
  37 int main(int argc, char **argv)
  38 {
  39         int sockfd;
  40         struct sockaddr_in servaddr;
  41
  42         bzero(&servaddr, sizeof(servaddr));
  43         servaddr.sin_family = AF_INET;
  44         servaddr.sin_port = htons(SERV_PORT);
  45         inet_aton("127.0.0.1",&(servaddr.sin_addr));
  46
  47         sockfd = socket(AF_INET, SOCK_DGRAM, 0);
  48
  49         do_cli(stdin, sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
  50
  51         return 0;
  52 }