Elementary GDS routines
The names of the elementary GDS routines all start with GDS_.
The application programmer does not normally need to call most of these
routines because this is done for him `behind the scenes' by other routines.
A selection of the most important routines is listed below.
- GDS_CLOSE
- Close set.
- GDS_CLOSEALL
- Close all sets.
- GDS_CREATE
- Create a new set.
- GDS_DELETE
- Delete set.
- GDS_ERRSTR
- Obtain the message string associated with a GDS error code.
- GDS_EXIST
- Test whether set exists.
- GDS_EXTEND
- create or extend an axis
- GDS_HANDLE
- Obtain a GDS set handle. Set handles can be used instead of set names
in calls to GDS routines. Doing this is more efficient.
- GDS_LOCK
- Obtain exclusive access to a set. Normally done when a number of
changes are made to a set which should all be done before an other
task may access the set.
- GDS_OPTIMIZE
- Modify lay-out of GDS descriptor file for efficient access.
Normally called when number of descriptor items has increased or
decreased by a large number. (`large' is several hundreds)
- GDS_RENAME
- Rename an existing GDS set
- GDS_SYNC
- Update descriptor file. Can be called to force the GDS server to write
out all changes to disk. Normally this is not necessary because the
server itself writes out changes every five minutes.
- GDS_UNLOCK
- Abandon exclusive access to a set.
