λ> bash
$ yes "" | make oldconfig
scripts/kconfig/conf --oldconfig Kconfig
#
# configuration written to .config
#
$ exit
λ> yes "" | make oldconfig
scripts/kconfig/conf --oldconfig Kconfig
#
# configuration written to .config
#
...
command does't exit...
^CERROR: <interactive>:1:7: signal: interrupt|success