进程间共享数据 linux

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

int main() {
    key_t key = ftok("shmfile", 65);
    int shmid = shmget(key, 1024, 0666|IPC_CREAT);
    char *str = (char*) shmat(shmid, (void*)0, 0);

    printf("Write Data: ");
    fgets(str, 1024, stdin);

    shmdt(str);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <sys/ipc.h>
#include <sys/sem.h>

union semun {
    int val;
    struct semid_ds *buf;
    unsigned short *array;
};

int main() {
    key_t key = ftok("semfile", 65);
    int semid = semget(key, 1, 0666|IPC_CREAT);
    union semun arg;
    arg.val = 1;
    semctl(semid, 0, SETVAL, arg);

    struct sembuf sb = {0, -1, SEM_UNDO};
    semop(semid, &sb, 1);

    // Critical Section
    printf("Inside critical section\n");

    sb.sem_op = 1;
    semop(semid, &sb, 1);
    return 0;
}