permoffset
#define permission(who, type) ((type) >> permoffset(who))
pmode[permoffset(who) + 1] = 'r';
pmode[permoffset(who) + 1] = '-';
pmode[permoffset(who) + 2] = 'w';
pmode[permoffset(who) + 2] = '-';
pmode[permoffset(who) + 3] =
pmode[permoffset(who) + 3] = 'x';
pmode[permoffset(who) + 3] = '-';
pmode[permoffset(who) + 1] = '+';
pmode[permoffset(who) + 1] = ' ';
pmode[permoffset(who) + 2] = '\0';