@

Use the @ function to position the cursor to a specific point on the terminal screen

TAFJ note: screen positioning doesn't work.

TAFJ R23 note: screen positioning is fixed.

COMMAND SYNTAX

    @ (col{,row})

SYNTAX ELEMENTS

col and row can be any expression that evaluates to a numeric value.

col specifies, to which column on the screen the cursor should be moved.

row specifies which row (line) on the screen to position the cursor.

Specifying col on its own will locate the cursor to the required column on whichever row it currently occupies.

NOTES

When specified values exceed either of the physical limits of the current terminal, then unpredictable results will occur.

The terminal address starts at (0,0), that being the top left hand corner of the screen.

Cursor addressing will not normally work when directed at a printer. If you wish to build printer independence into your programs, achieve this by accessing the terminfo database through the SYSTEM () function.

EXAMPLE

       FOR I = 1 TO 5
          CRT @(5, I) : "*" :
       NEXT I
       Home = @(0,0) ;* Remember the cursor home position
       CRT Home: "Hi honey, I'm HOME!" :

EXAMPLE 2

Here the screen will be drawn, parts of it redrawn and then cleared:

       size_x = SYSTEM(2) - 5 ; size_y = SYSTEM(3) - 5
       info_x = 1  ;  info_y = size_y + 1
       DIM the_screen(size_x, size_y)
       CRT @(-1)
       MAT the_screen = '*'
       left_offset = 1
       GOSUB DRAW.SCREEN
       MAT the_screen = '#'
       left_offset = INT(size_x / 2)
       GOSUB DRAW.SCREEN
       hole_x = 5  ;  hole_y = 5  ;  hole_len = 5
       GOSUB MAKE.HOLE
       hole_x = left_offset - 5  ;  hole_y = 10  ;  hole_len = 20
       GOSUB MAKE.HOLE
       CRT @(info_x, info_y) : "That's all folks!" : @(-3)
                      ;* -3 clears all to the end of line
       *
       STOP
       *
       DRAW.SCREEN:
          CRT @(info_x, info_y) : 'Drawing ' : the_screen(1, 1) : "'s..."
          FOR i = left_offset TO size_x
             FOR j = 1 TO size_y
                CRT @(i, j) : the_screen(i, j):
             NEXT j
          MSLEEP(100) ;* 0.1 sec
          NEXT i
          MSLEEP(2000)
          RETURN
       *
       MAKE.HOLE:
          CRT @(info_x, info_y) : 'Making a hole at ' : hole_x : '/' : hole_y
          CRT @(hole_x, hole_y) : STR(' ', hole_len)
          MSLEEP(2000)
          RETURN
       END