FT_DISPFILE()
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 Syntax

      FT_DISPFILE() -> cExitkey

 Arguments

     None

 Returns

     The ASCII keystroke that terminated FT_DISPFILE()

 Description

     This routine displays a text file within a defined window using as
     little memory as possible.  The text file to display has to be
     present or an error value of 0 is returned (as a character.)

     Assumptions: The routine assumes that all lines are terminated
                  with a CR/LF sequence (0x0d and 0x0a).

     Note:        Make sure you allocate a buffer large enough to hold
                  enough data for the number of lines that you have
                  in the window.  Use the following formula as a
                  guideline - buffer size = (# of line) + 1 * RMargin
                  this is the smallest you should make the buffer and
                  for normal use I recommend 4096 bytes.

     Cursor Keys: Up, Down    - moves the highlight line
                  Left, Right - moves the window over nColSkip col's
                  Home        - moves the window to the far left
                  End         - moves the window to the nRMargin column
                  PgUp, PgDn  - moves the highlight one page
                  Ctrl-PgUp   - moves the highlight to the file top
                  Ctrl-PgDn   - moves the highlight to the file bottom
                  Ctrl-Right  - moves the window 16 col's to the right
                  Ctrl-Left   - moves the window 16 col's to the left

                  Esc, Return - terminates the function

                  All other keys are ignored unless they are specified
                  within cExitKeys parameter.  This list will tell the
                  routine what keys terminate the function.  Special
                  keys must be passed by a unique value and that value
                  can be found by looking in the keys.h file.

 Examples

     @ 4,9 TO 11,71

     FT_DFSETUP("test.txt", 5, 10, 10, 70, 1, 7, 15,;
                 "AaBb" + Chr(143), .T., 5, 132, 4096)

     cKey = FT_DISPFILE()

     FT_DFCLOSE()

     @ 20,0 SAY "Key that terminated FT_DISPFILE() was: " + '[' + cKey + ']'

 Source: DISPC.C

 Author: Mike Taylor