Filename completion (=FNC) makes typing long filenames and directorynames
easier. It does not matter if you want to type it as command or as
argument. Just type some beginning characters of the desired name
(it also works if you press TAB without typing anything before
or if you give a path) and then press TAB . If there is more than one
possibility that match, it will only be completed as far as all
possibilities match and there are two ways to go further:

1. Type in the next character(s) then again press TAB .
2. Press TAB again: The first match will show up. Press TAB again and
   and again to walk through all matches (I call it cycling).
   To enter a directory shown (indicated by the trailing slash) press
   cursor-right. After you type any other key than TAB, it gets out of
   this cycling mode (cursor-right is the only key that will be ignored).
   To get back the commandline before cycling you can press
   shift-cursor-down.

If a filename was fully matched, a space after it will be inserted. If
a directoryname was fully matched, a slash (/) will be inserted after.
If no partial match is found, the screen blinks (display beep).

You can use wildcards with FNC, too. For example you type
  view env:sys/*ilbm
and then press TAB. This will be expanded to
  view env:sys/palette.ilbm
With this you can also check out which files match to a wildcard.

Instead of TAB, you can press CTRL-F, too. This will cause a filerequester
to pop up which shows all matches. Then you can choose one of these
matches or something else.

Maybe you do not want *.info files to be completed. This will avoid
some trouble. Use "config hide *.info" for that or see  CONFIG HIDE .
If you do not want to see all files that match, you can use
 FLAGS MATCH OFF .

To find out the advantage of FNC it is best to play around with it.
It is really a very convenient and powerful thing !

The contents of the directory last used by FNC is remembered, so it can
be used comfortably on slow floppy disks, too.
See  CONFIG FNCSIZE  for more.

For example a directory contains:
  MegaEditExample
  MegaEditExample.info
  MegaViewer
  MoreMegaFiles               {directory}

If you want to change the current directory to MoreMegaFiles you type:
    mo
then press the TAB key. You will see the full name with a slash at the
end. Just press RETURN and you changed it.
To delete MegaViewer you type:
    delete me
and press TAB . You will see "Mega". Now type the V key and
press TAB again. You see "delete MegaViewer ". Press RETURN and
it will be gone.
You want to start MegaEditExample. Type:
    me
and press TAB. Then type E and press TAB. There is no space after the
name. This is because MegaEditExample.info also matches.
Start it by pressing RETURN.