eshell-status-in-modeline

eshell-status-in-modeline is a variable defined in `esh-mode.el'.
Its value is

t

• This variable is an alias for `eshell-status-in-mode-line'.
• This variable is obsolete since 24.3;
  use `eshell-status-in-mode-line' instead.

Documentation:
If non-nil, let the user know a command is running in the mode line.

You can customize this variable.