1*4882a593Smuzhiyun #include <stdio.h>
2*4882a593Smuzhiyun #include <stdlib.h>
3*4882a593Smuzhiyun #include <unistd.h>
4*4882a593Smuzhiyun #include <sys/socket.h>
5*4882a593Smuzhiyun #include <netinet/in.h>
6*4882a593Smuzhiyun
main(int argc,char * argv[])7*4882a593Smuzhiyun int main (int argc, char *argv[])
8*4882a593Smuzhiyun {
9*4882a593Smuzhiyun int s, len, o, port = 6666;
10*4882a593Smuzhiyun char buf[512];
11*4882a593Smuzhiyun struct sockaddr_in addr;
12*4882a593Smuzhiyun socklen_t addr_len = sizeof addr;
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun if (argc > 1)
15*4882a593Smuzhiyun port = atoi (argv[1]);
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun s = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun o = 1;
20*4882a593Smuzhiyun len = 4;
21*4882a593Smuzhiyun setsockopt (3, SOL_SOCKET, SO_REUSEADDR, &o, len);
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun addr.sin_family = AF_INET;
24*4882a593Smuzhiyun addr.sin_port = htons (port);
25*4882a593Smuzhiyun addr.sin_addr.s_addr = INADDR_ANY; /* receive broadcasts */
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun bind (s, (struct sockaddr *) &addr, sizeof addr);
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun for (;;) {
30*4882a593Smuzhiyun len = recvfrom (s, buf, sizeof buf, 0, (struct sockaddr *) &addr, &addr_len);
31*4882a593Smuzhiyun if (len < 0)
32*4882a593Smuzhiyun break;
33*4882a593Smuzhiyun if (write (1, buf, len) != len)
34*4882a593Smuzhiyun fprintf(stderr, "WARNING: serial characters dropped\n");
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun return 0;
38*4882a593Smuzhiyun }
39