编写C程序，使用Linux中的IPC机制，完成 “石头、剪子、布”的游戏。

这里提供一种使用共享内存和信号量实现的方法：

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

#define SHM_KEY 0x1234
#define SEM_KEY 0x5678

#define ROCK 0
#define SCISSORS 1
#define PAPER 2

#define WIN 0
#define LOSE 1
#define DRAW 2

typedef struct {
    int player_choice;
    int computer_choice;
    int result;
} GameData;

void set_semvalue(int sem_id, int value) {
    union semun {
        int val;
        struct semid_ds *buf;
        unsigned short *array;
    } sem_union;

    sem_union.val = value;
    if (semctl(sem_id, 0, SETVAL, sem_union) == -1) {
        perror("semctl");
        exit(EXIT_FAILURE);
    }
}

void sem_wait(int sem_id) {
    struct sembuf sem_b;
    sem_b.sem_num = 0;
    sem_b.sem_op = -1;
    sem_b.sem_flg = SEM_UNDO;
    if (semop(sem_id, &sem_b, 1) == -1) {
        perror("semop");
        exit(EXIT_FAILURE);
    }
}

void sem_signal(int sem_id) {
    struct sembuf sem_b;
    sem_b.sem_num = 0;
    sem_b.sem_op = 1;
    sem_b.sem_flg = SEM_UNDO;
    if (semop(sem_id, &sem_b, 1) == -1) {
        perror("semop");
        exit(EXIT_FAILURE);
    }
}

int main() {
    srand(time(NULL));

    int shm_id = shmget(SHM_KEY, sizeof(GameData), IPC_CREAT | 0666);
    if (shm_id == -1) {
        perror("shmget");
        exit(EXIT_FAILURE);
    }

    GameData *game_data = shmat(shm_id, NULL, 0);
    if (game_data == (GameData *) -1) {
        perror("shmat");
        exit(EXIT_FAILURE);
    }

    int sem_id = semget(SEM_KEY, 1, IPC_CREAT | 0666);
    if (sem_id == -1) {
        perror("semget");
        exit(EXIT_FAILURE);
    }

    set_semvalue(sem_id, 0);

    while (1) {
        printf("Please input your choice (0 for rock, 1 for scissors, 2 for paper): ");
        scanf("%d", &(game_data->player_choice));

        game_data->computer_choice = rand() % 3;

        printf("You chose %d, computer chose %d\n", game_data->player_choice, game_data->computer_choice);

        if (game_data->player_choice == ROCK) {
            if (game_data->computer_choice == ROCK) {
                game_data->result = DRAW;
            } else if (game_data->computer_choice == SCISSORS) {
                game_data->result = WIN;
            } else if (game_data->computer_choice == PAPER) {
                game_data->result = LOSE;
            }
        } else if (game_data->player_choice == SCISSORS) {
            if (game_data->computer_choice == ROCK) {
                game_data->result = LOSE;
            } else if (game_data->computer_choice == SCISSORS) {
                game_data->result = DRAW;
            } else if (game_data->computer_choice == PAPER) {
                game_data->result = WIN;
            }
        } else if (game_data->player_choice == PAPER) {
            if (game_data->computer_choice == ROCK) {
                game_data->result = WIN;
            } else if (game_data->computer_choice == SCISSORS) {
                game_data->result = LOSE;
            } else if (game_data->computer_choice == PAPER) {
                game_data->result = DRAW;
            }
        }

        sem_signal(sem_id);

        sem_wait(sem_id);

        if (game_data->result == WIN) {
            printf("You win!\n");
        } else if (game_data->result == LOSE) {
            printf("You lose!\n");
        } else {
            printf("It's a draw!\n");
        }
    }

    if (shmdt(game_data) == -1) {
        perror("shmdt");
        exit(EXIT_FAILURE);
    }

    if (shmctl(shm_id, IPC_RMID, 0) == -1) {
        perror("shmctl");
        exit(EXIT_FAILURE);
    }

    if (semctl(sem_id, 0, IPC_RMID) == -1) {
        perror("semctl");
        exit(EXIT_FAILURE);
    }

    return 0;
}

在该程序中，使用了共享内存存储游戏数据，使用信号量实现了进程间同步。在主循环中，用户输入自己的选择后，程序随机生成计算机的选择，并根据规则判断胜负，并将结果存储在共享内存中。然后使用信号量通知另一个进程（如果有的话）可以读取共享内存中的结果了，自己则使用信号量等待结果的到来。最后根据结果输出胜负信息。