Check to see if file exists

[CAB2k]

Is there a way to see if a particular routine or file is loaded?

Just test the name of the lisp function.
If the name returns nil it is not loaded.
This example assumes a lisp file "MyLisp.lsp" and a defun c:MyLisp

(if (not c:MyLisp)
  (load "myLisp.lsp")
)

or use

(or c:Mylisp (load "myLisp.lsp"))

or use

(autoload "myLisp.lsp" '("MyLisp"))