This trap sets or reads the file version number.

Any I/O sub system errors including

• All registers not shown above are not used on entry and are preserved on exit.
• D1.L has three initial values:
  • -1 causes the file version number to be returned in D1.L.
  • 0 causes the the file version number to be set to its current value and returned in D1.L.
  • 1 to 65535 causes the value in D1.L to be set as the new version number. The value in D1.L is preserved on return.
• If the version number is set by this trap, it will not be incremented when the file is closed, or flushed.

The example below shows the use of this trap call to set the version number of a file in D7.L and prevent its being incremented when the file is closed.

vers    moveq   #io_open,d0     ; $01
        moveq   #-1,d1          ; This job
        moveq   #0,d3           ; OPEN
        lea     name,a1         ; Name of file 
        trap    #2              ; Open the file
        tst.l   d0              ; OK? . .
        bne     error           ; . . no!
        moveq   #0,d1           ; To find the version number
        moveq   #-1,d3          ; Timeout
        moveq   #iof_vers,d0    ; $4E
        trap    #3              ; Find the version
        tst.l   d0              ; OK? . .
        bne     error           ; . . no!
        move.l  d1,d7           ; Set the version number in D7.L
        moveq   #io_close,d0    ; $02
        tst.l   d0              ; OK? . .
        bne     error           ; . . no!


name    dc.w    name_e-name-2   ; Length of name
        dc.b    "flp1_klok"
name_e  ds.b    0