Com-port for arduino

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>

int open_port(const char *port) {
    int fd = open(port, O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd == -1) {
        perror("open_port: Unable to open port");
        return -1;
    }

    struct termios options;
    tcgetattr(fd, &options);
    cfsetispeed(&options, B9600);
    cfsetospeed(&options, B9600);
    options.c_cflag &= ~PARENB;
    options.c_cflag &= ~CSTOPB;
    options.c_cflag &= ~CSIZE;
    options.c_cflag |= CS8;
    options.c_cflag |= (CLOCAL | CREAD);
    tcsetattr(fd, TCSANOW, &options);

    return fd;
}

int main() {
    int fd = open_port("/dev/ttyUSB0");
    if (fd == -1) {
        return -1;
    }

    char write_buffer[] = "Hello Arduino!";
    int bytes_written = write(fd, write_buffer, strlen(write_buffer));
    if (bytes_written < 0) {
        perror("write");
        close(fd);
        return -1;
    }

    char read_buffer[256];
    int bytes_read = read(fd, &read_buffer, sizeof(read_buffer));
    if (bytes_read < 0) {
        perror("read");
        close(fd);
        return -1;
    }

    read_buffer[bytes_read] = '\0';
    printf("Received: %s\n", read_buffer);

    close(fd);

    return 0;
}