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

int main() {
    // Open a file for reading and writing
    int fd = open("example.txt", O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
    // int fd = 2; // jam in STDERR_FILENO ...
    if (fd == -1) {
        perror("Error opening file");
        return EXIT_FAILURE;
    }

    // Write to the file
    const char *text = "Hello, file descriptors!";
    ssize_t bytes_written = write(fd, text, strlen(text));
    if (bytes_written == -1) {
        perror("Error writing to file");
        close(fd);
        return EXIT_FAILURE;
    }

    // Move the file offset to the beginning
    if (lseek(fd, 0, SEEK_SET) == -1) {
        perror("Error seeking in file");
        close(fd);
        return EXIT_FAILURE;
    }

    // Read from the file
    char buffer[256];
    ssize_t bytes_read = read(fd, buffer, sizeof(buffer) - 1);
    if (bytes_read == -1) {
        perror("Error reading from file");
        close(fd);
        return EXIT_FAILURE;
    }

    // Null-terminate the buffer and print the content
    buffer[bytes_read] = '\0';
    printf("File content: %s\n", buffer);

    // Close the file
    if (close(fd) == -1) {
        perror("Error closing file");
        return EXIT_FAILURE;
    }

    return EXIT_SUCCESS;
}