Intercept the input in comint-mode. This can be used to run eshell command, or run some command in a terminal buffer from the command line in shell buffer. That is, this is to combine the best part of shell, eshell and term mode. For example, you can run eshell `grep' in the shell buffer, or when you run `top' in the shell buffer, a terminal buffer is poped to run it. SSH is supported to run command remotely.