SHF
{"shmat", 4, HEX, NOV, HID, DEC, DEX, SHF}, /* 0 */
{"shmget", 4, DEC, NOV, HID, KEY, UNS, SHF}, /* 3 */
#define LBLK2SEC(BLK, SHF) (daddr_t)((BLK) >> (SHF))