1 #include <sys/ipc.h> 2 #include <sys/stat.h> 3 ftok(const char * path,int id)4 key_t ftok(const char *path, int id) 5 { 6 struct stat st; 7 if (stat(path, &st) < 0) return -1; 8 9 return ((st.st_ino & 0xffff) | ((st.st_dev & 0xff) << 16) | ((id & 0xffu) << 24)); 10 } 11