The IDL command HELP is available to get information on all the
variables, procedure and functions currently in IDL's memory. By typing:
IDL> help
IDL> help, data
you get a list of all of the variables that are defined within the current
IDL session. If you want information the definition of a structure, you
can use the /STRUCTURE option. Some examples are:
IDL> help, /st, roadmap
IDL> help, /st, index.gen
It is possible to get information on the calling parameters of procedures and
functions that have already been compiled by typing:
IDL> help, /routine
The procedure and function name is listed first. The positional parameters are
listed in lower case and the keyword parameters are in upper case.