F_MAP
{F_MAP, 'm'}, /* mapped file */
if (arg & ~(F_CDIR|F_RDIR|F_TEXT|F_MAP|F_OPEN|F_TRACE|F_TTY)) {
if (arg & F_MAP)
use_flag |= F_MAP;
use_flag |= F_MAP;
use_flag |= F_MAP;
use_flag |= F_MAP;