Task HISSET lets you set the history update mode. The default is "Normal", thus here the command
% hisset hr1068
switches normal history recording on for NDF hr1068. Thereafter whenever you alter this NDF, or create another NDF from it, the task automatically records the name of the application that was run, the date and time, a reference name that identifies the NDF, your username, and some text comprising the command-line parameters and the full path of the application. In KAPPA the package name and version is appended to the application name. Other packages may provide task-dependent additional text.
If disc space is not a concern, you might prefer the verbose level.
% hisset hr1068 verbose
the supplementary information being the machine type, and its operating system name and version.
For small datasets, such as spectra, the history can amount to a significant part of the NDF's size, so for these you might prefer the quiet level. This does not record the command line.
HISSET lets you switch off history recording, if you want to do something `off the record', or erase the history altogether.
% hisset hr1068 disabled % hisset hr1068 erase
Some applications create new NDFs from scratch, not inheriting the
history records and update mode from an input NDF. Some examples are
CREFRAME, TRANDAT, and
PSF. Should you wish these to have history
recording enabled as you create such NDFs, there is an environment
variable NDF_AUTO_HISTORY that should be set to a non-zero
integer value, or immediately run HISSET with the new NDF.
Note that some applications may choose to disregard the value of NDF_AUTO_HISTORY for good reason, such as for ancillary NDFs
created with an NDF extension. Whenever this option is exercised, the
reference documentation for the task should indicate this behaviour in
its Implementation Notes. There are currently no such applications in
KAPPA --- Kernel Application Package