#include<stdio.h>
#include<sys/mman.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>

int main() {
    const char *name = "/my_shared_memory";
    int shm_fd = shm_open(name, O_CREAT | O_RDWR, 0666);
    if (shm_fd == -1) {
        perror("shm_open");
        return 1;
    }

    // Set the size of the shared memory region
    size_t size = 1024;

    // Resize the shared memory object to the desired size
    if (ftruncate(shm_fd, size) == -1) {
        perror("ftruncate");
        return 1;
    }

    // Map the shared memory object into the process address space
    void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
    if (ptr == MAP_FAILED) {
        perror("mmap");
        return 1;
    }

    // Write data to the shared memory
    sprintf(ptr, "Hello, shared memory!");

    // Unmap the shared memory object
    if (munmap(ptr, size) == -1) {
        perror("munmap");
        return 1;
    }

    // Close the shared memory file descriptor
    if (close(shm_fd) == -1) {
        perror("close");
        return 1;
    }

    // Unlink the shared memory object
    if (shm_unlink(name) == -1) {
        perror("shm_unlink");
        return 1;
    }

    return 0;
}