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Internally LEXT holds images and lists in its own in a stack system. There
is a separate stack for lists and images. Each stack position is referred
to as a slot. The dimensions of the slots and stacks are defined in a
startup file (ie. the maximum size of both images and lists and the number
of image and list slots). If this is not present in the default directory
then the required values are prompted for.
The following commands allow stack examination and manipulation:
- DIRECTORY provides information on all the slots
of the current mode.
- EMPTY is used to clear a slot.
By default this command works on the current slot, although
a slot number or /ALL may be given as a parameter.
This command works irrespective of the state (protection) of the slot,
and the data is lost. (In fact images erroneously deleted may be
recovered as they should still reside in the LDSS_STACK directory).
- COPY copies a whole slot to another slot location.
Only the is changed to one which reflects the fact that
it is a duplicate.
The destination slot must not be protected.
In list mode an additional qualifier /COLUMNS allows extra
columns to be appended to the output.
- BACK steps the slot pointer back one position (with wrap-around).
- NEXT steps the slot pointer forwards one position (with
- USE allows specification of current slot number. Alternatively
just typing the number of the required slot on the command line
is acceptable shorthand. USE/TYPE allows the specification
of the slot desired. Obviously this option will only work
if there is just one slot of that type in the stack.