Please make sure you have the latest version. I recall fixing it, and it works for me right now.
** Changed in: mksh Status: New => Invalid -- You received this bug notification because you are a member of mksh Mailing List, which is subscribed to mksh. Matching subscriptions: mkshlist-to-mksh-bugmail https://bugs.launchpad.net/bugs/1616692 Title: ^C doesn't interrupt cat builtin when reading from /dev/zero Status in mksh: Confirmed Bug description: bash$ ./mksh $ cat < /dev/zero > /dev/null ^C^C^C^C^C^C^C To manage notifications about this bug go to: https://bugs.launchpad.net/mksh/+bug/1616692/+subscriptions