zhangyang-libzt/tests/udp_client.c

// UDP Client test program

#include <sys/socket.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/socket.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

int main(int argc, char * argv[])
{
    if(argc < 3) {
        printf("usage: udp_client <addr> <port>\n");
        return 0;
    }
    int sock = -1, port = atoi(argv[1]);
    ssize_t n_sent;
    struct sockaddr_in server;
    char buf[64];    

    if(sock == -1) {
        sock = socket(AF_INET , SOCK_DGRAM , 0);
        if (sock == -1) {
            return 1;
        }
    }
    // Construct address
    server.sin_addr.s_addr = inet_addr(argv[1]);
    server.sin_family = AF_INET;
    server.sin_port = htons(port);
    // Connect to server
    if (connect(sock , (struct sockaddr *)&server , sizeof(server)) < 0) {
        printf("api_test: error while connecting.\n");
        return 1;    
	}

    // TX
    char *msg = "Welcome to the Machine";
    int count = 0;
    
    while(1) {
        count++;
        usleep(1000000);
        n_sent = send(sock,msg,sizeof(msg),0);

        if (n_sent<0) {
            perror("Problem sending data");
            return 1;
        }
        if (n_sent!=sizeof(msg))
            printf("Sendto sent %d bytes\n",(int)n_sent);
        printf("n_sent = %d, count = %d\n", n_sent,count);
    } 
    
    // RX from server
    /*
    socklen_t recv_addr_len;
    // Clear address info for RX test
    server.sin_addr.s_addr = inet_addr("");
    server.sin_port = htons(-1);
    
    while (1) {
        n_sent=recvfrom(sock,buf,sizeof(buf),0,(struct sockaddr *)&server,&recv_addr_len);
        printf("Got a datagram from %s port %d\n", inet_ntoa(server.sin_addr), ntohs(server.sin_port));
        if (n_sent<0) {
            perror("Error receiving data");
        }
        else {
            printf("RXed: %s\n", buf);
        }
    }
    */
    return 1;
}