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

extern int errno;

#define SIZE    1

char *detect_key;
int shmid;

int shared_init()
{
        if((shmid = shmget(9999, SIZE, 0444)) < 0) {
                printf("Erreur dans shmget. Errno est : %d\n", errno);
                return -1;
        }
        if((detect_key = shmat(shmid, NULL, SHM_RDONLY)) < 0) {
                printf("Erreur dans shm attach. Errno est : %d\n", errno);
                return -1;
        }
//      detect_key = NULL;
        return 0;
}

void detect_hit()
{
        char c;
        c = *detect_key;
        while(1) {
                if(c != *detect_key) {
                        if(isalnum(detect_key[0])) {
                                printf("detect_key est %s\n", detect_key);
                                shmdt(detect_key);
                                shmctl(shmid, IPC_RMID, NULL);
                                exit(1);
                        } else {
                                printf("detect_key est %s\n", detect_key);
                        }
                        c = *detect_key;
                }
        }
}

int main()
{
        if(shared_init() < 0) {
                printf("Problèmes avec la mémoire partagée\n");
                exit(1);
        }
        detect_hit();
        return 0;
}