jd smith

After dealing with Mac-based path peculiarities (Ken, covering the
slightly different environment setup is a must for your FAQ site),
IDLWAVE in Carbon or X11 Emacs works great.

I would guess most people's IDL OSX path problems arise from running
the IDLDE or Emacs+IDLWAVE from the OSX dock, /Applications directory,
or some other launcher, after having setup their the environment
variable IDL_PATH in .login/.bashrc/.cshrc.

In Linux, starting IDLDE from the window manager works fine, because
there is an initial login shell which is loaded "above" the window
manager, which reads these shell config files and modifies the global
environment. Under OSX, this isn't the case. Things in .cshrc, for
instance, will only affect the environment of programs run from the
terminal where that shell is running. To modify the global
environment, you need to use environment.plist.

The easiest way to modify the IDL_PATH on this plist file is to use
the "defaults" command: % mkdir .MacOSX
% defaults write ~/.MacOSX/environment IDL_PATH "'<IDL_DEFAULT>:+${HOME}/idl'"

and then logout and back in again. Please note the nested quotes
(necessary because of all the <+: noise). Now IDL_PATH will be set
for all processes, whether they are started from the terminal or not.
You can always remove it like:

% defaults delete ~/.MacOSX/environment IDL_PATH

Note that IDL provides its own, separate "preferences" system which
can include things like the IDL_PATH. You can interact with this from
IDLDE, or even the IDL command line. This would be another option for
modifying the IDL_PATH.

JD