Help me understand two lisp sentences

Good afternoon all,

Please help me read the lisp sentences.

1, (if (not xxx:filename) ......)

Why is "xxx:" put there? What does this mean?

2, (command ".undo" "be")

What does this mean?

When should we put ".undo" in lisp?

Thanks a lot

san

1) xxx:filename may just be a variable name - the xxx: doesn't mean anything in particular.

2) (command ".undo" "be")

Starts an undo mark so that, when the undo mark is ended, all the operations performed between the markers can be undone in one undo command.

1) xxx:filename may just be a variable name - the xxx: doesn't mean anything in particular.

 

2) (command ".undo" "be")

 

Starts an undo mark so that, when the undo mark is ended, all the operations performed between the markers can be undone in one undo command.

Thank you Lee for your quick answer.

I try to understand

What does "be" mean in sentence 2)

Thanks again

san

What does "be" mean in sentence 2)

 

The "be" begins the undo command.