From MdsWiki
TDI (Tree Data Interface) Information
To use a new locally written TDI function (.FUN file) in an MDSPlus node or expression, it is necessary to put the file into the search-list MDS$PATH (VMS) or MDS_PATH (all other platforms). When defining the MDS_PATH environment variable use a semi-colon to delimit the directories to be searched. MDSplus will look at those directories (and all directories below those directories in the file system) when trying to find a TDI function. You should be cautious when defining MDS_PATH to avoid time consuming searches through unrelated directories. For instance, if you have private tdi functions you should might put them in a subdirectory of your login directory. Don't put your login directory in MDS_PATH but instead put this specific subdirectory. That way MDSplus will not need to search all the subdirectories of your login directory when trying to find a function. For example:
$ export MDS_PATH=/usr/local/mdsplus/tdi\;/home/twf/tdi
This would first look for functions in the standard MDSplus location and then if it can't find it there, look in the /home/twf/tdi directory tree.
Intrinsics PDF
Intrinsics - the built-in functions provided by TDI
- One line call descriptions with links to full descriptions
- Intrinsics grouped by function