Routines for controling recording of GRP group contents

The functions described in this section allow the contents of GRP groups to be appended to the default history record written by the NDF library.

If an ADAM application accesses a parameter as a GRP group, the default history record added by the NDF library to any output NDFs will include the group expression supplied in response to the associated parameter prompt. This is not always very informative - for instance, if the group expression gives the name of a file from which the group contents are to be read, rather than giving the group contents directly, then name of the file will be recorded in the default history record but not the contents of the file.

The NDG functions described below allow the default history record to be expanded to include the contents of any GRP group parameters accessed by the application. The contents of each such group is described in a new line of text that begings with the string ``Group: <PARAM>='', where <PARAM> is the name of the parameter with which the group is associated.

There are two parts to using these facilities:

1. Each time a group parameter is accessed, the group must be ``registered'' with NDG using ndgAddgh (NDG_ADDGH).
2. Before the application accesses any group parameters, it must begin a ``GRP history'' block by calling ndgBeggh (NDG_BEGGH). When the application has finished accessing group parameters, and producing output NDFs, it should end the GRP history block by calling ndgEndgh (NDG_ENDGH).

During a GRP history block, a record is kept of all NDFs to which the NDF library writes default history information. When ndgEndgh is called, the contents of all groups registered using ndgAddgh within the GRP history block, are appended to the current history record in each of the NDFs to which default history has been written.

Note, within a GRP history block, it is possible to prevent selected NDFs receiving this extra information by using ndgHltgh (NDG_HLTGH) to stop the recording of NDF names before the NDFs identifiers are annulled (which is normally when the default history is written out), and then calling ndgHltgh again afterwards to re-establish the recording of NDF names.

The C interfaces are the direct equivalent of the F77 interfaces described below - convert the F77 name to lower-case, remove the underscore and capitalise the following character.