NG
( >/dev/tty ) && echo ok || echo fail
Size: a a a
NG
( >/dev/tty ) && echo ok || echo fail
NG
VG
VG
VG
NG
VG
( >/dev/tty ) && echo ok || echo fail
NG
VG
NG
NG
VG
VG
VG
NG
( </dev/null >/dev/tty ) && echo ok || echo fail
VG
( </dev/null >/dev/tty ) && echo ok || echo fail
NG
NG
VG
VG