Path Preferences
This tab allows you to control where IDL looks for procedures and functions. The path elements specified in the Search Path / IDL Files Search Path are used to set the !PATH system variable when the IDLDE starts.
If you have set the environment variable IDL_PATH, IDL will set the !PATH system variable based the contents of the IDL_PATH environment variable at startup, overriding any settings made in this dialog. After IDL has started, however, you can modify the current value of the !PATH system variable using this dialog. See !PATH for additional details on how !PATH is set.
Search Path / IDL Files Search Path
The IDLDE Path Preferences dialog uses the same mechanism to expand the elements of the Search Path field as is used by the EXPAND_PATH function. By default, this field is populated with a single entry: <IDL_DEFAULT>, indicating that the default IDL path will be used. If the IDL_PATH environment variable is not set, when the IDLDE starts up, it will expand this token into the default value of the !PATH system variable. See The Path Definition String under EXPAND_PATH for complete details on how this token is expanded.
If the box to the left of a path element is checked, all directories below the listed directory that contain at least one .pro or .sav file will be included in !PATH. (This mechanism is analogous to the use of a "+" symbol in an EXPAND_PATH path definition string.)
If the <IDL_DEFAULT> entry is present, the box to its left is both checked and greyed out (Windows) or completely blacked out (Motif), indicating that the token will always be expanded.
You can modify the value of the !PATH system variable in the following ways using this dialog:
- Change the order of the path elements - using the up- and down-arrows, you can reorder the path elements. When searching the directories in the !PATH system variable for files, IDL will use the first matching file it finds. If you have multiple files with the same name in different directories within !PATH, you may need to adjust the order in which the directories are scanned.
- Insert... - To add a path to the Search Path list, click Insert... to display the Select Directory dialog. The new path is inserted before the first selected path. If none of the paths are selected, the new path is appended to the end of the list.
- Insert Standard Libraries - Click Insert Standard Libraries to insert the
<IDL_DEFAULT> path element into the list.
- Remove - Click on Remove to delete the selected path.
- Expand - Click on Expand to include the individual subdirectories of the selected path element in the Search Path list. When you click Expand, the checkmark is removed from the original path element, since the subdirectories are now explicitly included in the path search list.
See Running IDL Programs for more information on how !PATH is used by IDL when compiling and running programs.
Enable Path Cache
Select Enable Path Cache to enable IDL's path caching mechanism. Path caching is enabled by default, and in almost all cases should be left enabled. See PATH_CACHE for more information about IDL's path cache.
