In a command shell, everything is done by invoking commands. This chapter covers command invocations in Eshell, including the command history and invoking commands in a script file.
Unlike regular system shells, Eshell never invokes kernel functions
directly, such as exec(3). Instead, it uses the Lisp functions
available in the Emacs Lisp library. It does this by transforming the
input line into a callable Lisp form.4
To see the Lisp form that will be invoked, type this as the Eshell prompt: eshell-parse-command 'echo hello'