holidaywork3

1. 使用管道进行进程间通信：

#include 
#include 

int main() {
    int pipe_fd[2];
    char data[] = "Hello, Pipe!";
    char buffer[20];

    if (pipe(pipe_fd) == -1) {
        perror("Pipe creation failed");
        return 1;
    }

    if (fork() == 0) {  // Child process
        close(pipe_fd[0]);  // Close the read end
        write(pipe_fd[1], data, sizeof(data));
        close(pipe_fd[1]);
    } else {  // Parent process
        close(pipe_fd[1]);  // Close the write end
        read(pipe_fd[0], buffer, sizeof(buffer));
        close(pipe_fd[0]);

        printf("Received data: %s\n", buffer);
    }

    return 0;
}

1. 使用共享内存进行进程间通信：

#include 
#include 
#include 

int main() {
    size_t size = 4096;  // Size of shared memory
    char data[] = "Hello, Shared Memory!";
    char *shared_memory;

    int shm_fd = shm_open("/my_shared_memory", O_CREAT | O_RDWR, 0666);
    ftruncate(shm_fd, size);
    shared_memory = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);

    if (fork() == 0) {  // Child process
        sprintf(shared_memory, "%s", data);
    } else {  // Parent process
        wait(NULL);  // Wait for the child to finish writing
        printf("Received data: %s\n", shared_memory);

        shm_unlink("/my_shared_memory");  // Unlink shared memory
    }

    return 0;
}

1. 使用消息队列进行进程间通信：

#include 
#include 
#include 
#include 

struct msg_buffer {
    long msg_type;
    char msg_text[100];
};

int main() {
    key_t key;
    int msg_id;
    struct msg_buffer message;

    key = ftok("/tmp", 'a');
    msg_id = msgget(key, 0666 | IPC_CREAT);

    if (fork() == 0) {  // Child process
        message.msg_type = 1;
        sprintf(message.msg_text, "Hello, Message Queue!");
        msgsnd(msg_id, &message, sizeof(message), 0);
    } else {  // Parent process
        wait(NULL);  // Wait for the child to finish sending
        msgrcv(msg_id, &message, sizeof(message), 1, 0);
        printf("Received data: %s\n", message.msg_text);

        msgctl(msg_id, IPC_RMID, NULL);  // Remove message queue
    }

    return 0;
}