#define _XOPEN_SOURCE 700 #include #include #include #include #include "deonebook.h" unsigned char *readkey(const char *path) { key_t key = ftok(path, 0x2a); if (key == (key_t)(-1)) { perror("ftok"); return NULL; } int shmid = shmget(key, 0, 0); if (shmid == -1) { perror("shmget"); return NULL; } return shmat(shmid, NULL, 0); }