linux 共享内存 方案

#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define SHM_SIZE 1024

int main() {
    key_t key = ftok("shmfile", 65);
    int shmid = shmget(key, SHM_SIZE, 0666 | IPC_CREAT);
    char *str = (char*) shmat(shmid, (void*)0, 0);

    printf("Writing to shared memory: \"%s\"
", "Hello, World!");
    strncpy(str, "Hello, World!", SHM_SIZE);

    shmdt(str);
    return 0;
}

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

#define SHM_NAME "/my_shm"
#define SHM_SIZE 1024

int main() {
    int shm_fd = shm_open(SHM_NAME, O_CREAT | O_RDWR, 0666);
    ftruncate(shm_fd, SHM_SIZE);
    char *str = (char*) mmap(0, SHM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);

    printf("Writing to shared memory: \"%s\"
", "Hello, POSIX!");
    strncpy(str, "Hello, POSIX!", SHM_SIZE);

    munmap(str, SHM_SIZE);
    shm_unlink(SHM_NAME);
    return 0;
}