#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/socket.h> #include <netinet/in.h> int main (int argc, char *argv[]) { int s, len, o, port = 6666; char buf[512]; struct sockaddr_in addr; socklen_t addr_len = sizeof addr; if (argc > 1) port = atoi (argv[1]); s = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP); o = 1; len = 4; setsockopt (3, SOL_SOCKET, SO_REUSEADDR, &o, len); addr.sin_family = AF_INET; addr.sin_port = htons (port); addr.sin_addr.s_addr = INADDR_ANY; /* receive broadcasts */ bind (s, (struct sockaddr *) &addr, sizeof addr); for (;;) { len = recvfrom (s, buf, sizeof buf, 0, (struct sockaddr *) &addr, &addr_len); if (len < 0) break; if (write (1, buf, len) != len) fprintf(stderr, "WARNING: serial characters dropped\n"); } return 0; }