eshell-structure-basic-command
eshell-structure-basic-command is a compiled Lisp function in `esh-cmd.el
'.
(eshell-structure-basic-command FUNC NAMES KEYWORD TEST BODY &optional ELSE)
With TERMS, KEYWORD, and two NAMES, structure a basic command.
The first of NAMES should be the positive form, and the second the
negative. It's not likely that users should ever need to call this
function.