| 1 | //#define _GNU_SOURCE |
| 2 | |
| 3 | #include <stdio.h> |
| 4 | #include <sys/types.h> |
| 5 | #include <sys/stat.h> |
| 6 | #include <sys/mman.h> |
| 7 | #include <fcntl.h> |
| 8 | #include <unistd.h> |
| 9 | #include <string.h> |
| 10 | |
| 11 | #define MEM_PATH "hello.bin" |
| 12 | #define MEM_SIZE 1048576 |
| 13 | |
| 14 | int main() { |
| 15 | int fd; |
| 16 | fd = open(MEM_PATH, O_RDWR | O_SYNC | O_CREAT | O_CLOEXEC, S_IRUSR | S_IWUSR); |
| 17 | ftruncate(fd, MEM_SIZE); |
| 18 | |
| 19 | void *mem; |
| 20 | mem = mmap(NULL, MEM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED , fd, 0); |
| 21 | close(fd); |
| 22 | |
| 23 | char hello[] = "Hello!"; |
| 24 | memcpy(mem, hello, sizeof(hello)); |
| 25 | msync(mem, sizeof(hello), MS_SYNC); |
| 26 | } |