QDOS Internals

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
====== IOF_VERS ======


This trap sets or reads the file version number.

^Call Parameters^^Return Parameters^^
|D0.B|$4E|D0.L|Error return.|
|D1.L|Version |D1.L|Version.|
|D3.W|Timeout |D3.L|Preserved.|
|A0.L|Channel ID |A0.L|Preserved.|

===== Errors =====
Any I/O sub system errors including 
|ERR_NC|Not complete.|



===== Notes =====
  * 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.

===== Example =====
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.

<code>
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        
</code>
QDOS Internals

User Tools

Site Tools

Page Tools
