Linux Client TCP/IP for Modelica

#include <stdio.h>
#include <stdlib.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#include <string.h>

double RPI(double val, double m_time) {

    // logging
    FILE *log = fopen("/home/czajos/MOS/log.txt", "a+");
    if (log == NULL) {
        return -1;
    }
    // time log
    fprintf(log, "time %f\r\n", m_time);

    int sd, portno, n;
    struct sockaddr_in serv_addr;
    struct hostent *server;

    char buffer[256];

    // Create a socket point
    sd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

    if (sd < 0) {
        fprintf(log, "opening socket FAILED\r\n");
        return 1;
    }

    // setup socket
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr("192.168.0.14");
    serv_addr.sin_port = htons(8888);

    // connect
    if (connect(sd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) < 0) {
        fprintf(log, "connecting FAILED\r\n");
        return 1;
    }

    // turn led on/off depending on the value
    int slen = sprintf(buffer, "%d", (int)(val) % 2) + 1;

    // send value to RPI
    int bwrote = write(sd, buffer, slen);
    if (bwrote < 0) {
        fprintf(log, "writing to socket FAILED\r\n");
    }
    // shutdown write ops.
    shutdown(sd, SHUT_WR);

    // receive RPI temperature
    double temp = -1;
    int bread = read(sd, buffer, 256);
    if (bread > 0) {
        fprintf(log, "%d received\r\n", bread);
        temp = atof(buffer);
    } else if (bread == 0) {
        fprintf(log, "none received\r\n");
    } else {
        fprintf(log, "receive FAILED\r\n");
    }

    // shutdown read ops.
    shutdown(sd, SHUT_RD);
    // close socket
    int result = close(sd);
    if (result == 0) {
        fprintf(log, "close OK\r\n");
    } else {
        fprintf(log, "close FAILED\r\n");
    }

    // optional sleep
    usleep(100*1000);

    // return temperature
    return temp;
}