#include <stdio.h> /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket(), connect(), sendto(), and recvfrom() */
#include <arpa/inet.h> /* for sockaddr_in and inet_addr() */
#include <stdlib.h> /* for atoi() and exit() */
#include <string.h> /* for memset() */
#include <unistd.h> /* for close() */
#define MAXRECVSTRING 255 /* Longest string to receive */
int main(int argc, char *argv[])
{
int sock; /* Socket */
struct sockaddr_in broadcastAddr; /* Broadcast Address */
unsigned int broadcastPort; /* Port */
char recvString[MAXRECVSTRING+1]; /* Buffer for received string */
int recvStringLen; /* Length of received string */
if (argc != 2) /* Test for correct number of arguments */
{
fprintf(stderr,"Usage: %s <Broadcast Port>\n", argv[0]);
exit(1);
}
broadcastPort = atoi(argv[1]); /* First arg: broadcast port */
/* Create a best-effort datagram socket using UDP */
if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
printf("socket() failed");
/* Construct bind structure */
memset(&broadcastAddr, 0, sizeof(broadcastAddr)); /* Zero out structure */
broadcastAddr.sin_family = AF_INET; /* Internet address family */
broadcastAddr.sin_addr.s_addr = htonl(INADDR_ANY); /* Any incoming interface */
broadcastAddr.sin_port = htons(broadcastPort); /* Broadcast port */
/* Bind to the broadcast port */
if (bind(sock, (struct sockaddr *) &broadcastAddr, sizeof(broadcastAddr)) < 0)
printf("bind() failed");
/* Receive a single datagram from the server */
if ((recvStringLen = recvfrom(sock, recvString, MAXRECVSTRING, 0, NULL, 0)) < 0)
printf("recvfrom() failed");
recvString[recvStringLen] = '\0';
printf("Received: %s\n", recvString); /* Print the received string */
close(sock);
exit(0);
}