I've written some IDL code that carries out some analysis interactively. What I'd like to do is then use that information as input to some compiled C code routines which I run via a "spawn" command within IDL. The problem is that the routines require a set of environment variables to be set in order to run. I do that (outside of IDL) by source'ing a shell script. However, it seems that IDL doesn't retain those environment variables. Is there any way to make sure IDL retains those variables -- or to pass the variables to the shell within which spawn executes commands? Any information about the environment in which IDL executes spawn commands would be helpful. By the way, one workaround I found is to write out the commands to a file (i.e. creating a shell script) and then executing that via a spawn command, but that's kind of cumbersome.