idlwave-shell-prompt-pattern

idlwave-shell-prompt-pattern is a variable defined in `idlw-shell.el'.
Its value is

"^
? ?IDL> "

Documentation:
Regexp to match IDL prompt at beginning of a line.
For example, "^ ?IDL> " or "^ ?WAVE> ".
The "^ ?" is needed, to indicate the beginning of the line, with
optional return character (which IDL seems to output randomly).
This variable is used to initialize `comint-prompt-regexp' in the
process buffer.

You can customize this variable.