[Info-vax] About $ run /mailbox DCL command

[Michael Moroney]

hb <becker.avd at gmail.com> writes:

>On Jan 4, 4:53=A0pm, IanMiller <g... at uk2.net> wrote:
>> I don't think the mailbox driver supports a timeout directly.
>> In a program you can set a timer and abort the I/O.

>The mailbox driver supports IO$M_NOW. That's not a timeout, or only a
>very short one :-) It looks like the DCL read doesn't set this I/O
>modifier for mailboxes; neither by default nor on request. Coding an
>own read utility with this looks like a SMOP.

If I recall correctly, READ/TIME_OUT=0 does set IO$M_NOW on a mailbox
read.  No other values for /TIME_OUT are supported or work.