<shameless-plug> You may also like to have a look at https://github.com/akavel/up https://github.com/akavel/up as an alternative. It now executes the command on

<shameless-plug> You may also like to have a look at https://github.com/akavel/up https://github.com/akavel/up as an alternative. It now executes the command only after Enter is pressed (though originally I also went with execution on every keypress). By default it runs shell commands/pipelines, but you can change the contents of SHELL env. variable to write raw ruby, awk, or else.