FZENDO - output file termination

To terminate one or all output files:

CALL FZENDO (LUN,options)

with    LUN:  logical unit number
               if zero: all FZ output files

    options:  character string,
               individual characters select options:

         main:  T  terminate:
                    - ensure end-of-data (unless done)
                    - print file statistics (unless done)
                    - drop FZ control-bank

                 N  continue output to a new file to be connected
                    by the user to LUN after this call:
                    - ensure end-of-data (unless done)
                    - print file statistics (unless done)

                 C  continue on the next file of the same stream:
                    - ensure end-of-file (unless done)
                    - print file statistics (unless done)

                 I  switch to input, to read the file just written:
                    - ensure end-of-data (unless done)
                    - print file statistics (unless done)
                    - remove the 'output' permission
                    - rewind and change status to 'input'

                 O  output again, to over-write the file just written:
                    - ensure end-of-data (unless done)
                    - print file statistics (unless done)
                    - rewind

              none  print file statistics only

                    over-ruling:   T -> N -> C -> I -> O

     variants:  R  execute REWIND function, only with T or N
                 U  execute UNLOAD function, only with T or N (no action yet)
                 X  execute CLOSE function, only with T or N
                 O  keep the 'output' permission, only with I
                 Q  quiet, suppress printing of file statistics
        0,1,2 or 3  only with I: change the NEOF parameter
                    of FZFILE for reading

If necessary this is taken as a final close-down signal to be passed on to special I/O packages on some machines (such as IOPACK on IBM).