[Info-vax] QIO Writes to a mailbox

[Bob Koehler]

In article <4eb4b6fc$0$20129$c3e8da3$92d0a893 at news.astraweb.com>, JF Mezei <jfmezei.spamnot at vaxination.ca> writes:
> 
> If you look at the documentation for QIO, it should list the status
> codes that can be issued by status = SYS$QIO(mumble)

   If you trust that documentation, just wait until you get a return
   value of 9 (ACCVIO, with a success field) from $QIO[W].

   You can trust the lsb to tell you whether or not it was success,
   and the fields checked by LIB$MATCH_CONDITION to find out what it
   was, but in addition to $QIO returning 9, I've had to deal with
   the results after a user-written handler set the inhibit message
   bit.  And I've had cause to set that bit myself.