client_win32.c

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <winsock2.h>
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <unistd.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

#ifdef _WIN32
#pragma comment(lib,"ws2_32.lib")
#endif

char *getmessage() {
    srand(time(0));
    const char *header = "POST / HTTP/1.1\r\nContent-Type: application/json\r\nContent-Length: %d\r\n\r\n%s";
    const char *json = "\"name\":\"%s\",\"interval\":%d,\"value\":%d";
    
    int l = (strlen(json)*10);
    char* json_list = (char *)malloc(l);
    memset(json_list, '\0', l);
    
    char tmp[1024] = {0};
    strcat(json_list, "{");
    sprintf(tmp, json, "system", 60, rand()%11);
    strcat(json_list, tmp);
    strcat(json_list, "}");
    
    l = (strlen(json_list) + strlen(header))*2;
    char* result = (char *)malloc(l);
    sprintf(result, header, strlen(json_list), json_list);
    free(json_list);

    return result;
}

int senddata() {
#ifdef _WIN32
    WSADATA wsaData = {0};
    SOCKET sock = INVALID_SOCKET;
#else
    int sock = 0;
#endif
    struct sockaddr_in server;
    char *message = 0;
    char server_reply[2000] = {0};
    int recv_size = 0;

#ifdef _WIN32
    printf("Initializing socket\n");
    if(WSAStartup(0x101,&wsaData) != 0) {
        printf("ERROR: initializing socket\n");
        return -1;
    }

    printf("Initialized\n");
#endif

    if((sock=socket(AF_INET,SOCK_STREAM,0)) < 0 ) {
        printf("ERROR: creating socket\n");
        return -2;
    }

    printf("Socket created\n");

    server.sin_addr.s_addr = inet_addr("127.0.0.1");
    server.sin_family = AF_INET;
    server.sin_port = htons( 8889 );

    if (connect( sock, (struct sockaddr *)&server , sizeof(server)) < 0) {
        printf("ERROR: connecting socket\n");
        return -3;
    }

    printf("Socket connected\n");
    message = getmessage();
    if( send(sock , message , strlen(message) , 0) < 0)
    {
        printf("Send failed\n");
        return -4;
    }
    
    free(message);

    return 0;
}

int main(int argc, char *argv[]) {
    time_t last = time(0);
    for(;;) {
        if ((time(0)-last)==5) {
            senddata();
            last = time(0);
        }
#ifdef _WIN32
        Sleep(100);
#else
        usleep(100 * 1000);
#endif        
    }        
}