PR_PATH_LIB will search directories in the IDL !path variable in the
order of the list to find a given IDL program. The default is to
only give the first instance that the file is found, but it is possible to
get all locations by using the /multi switch. A wild card (`*')
effectively sets the /multi switch).
For example,
IDL> pr_path_lib,'gt_*'
will return a list of all ``gt_'' routines and their directory locations.