[Info-vax] VMS Features I Wish Linux Had

[Johnny Billquist]

On 2016-06-16 22:20, Chris Scheers wrote:
> Johnny Billquist wrote:

>> Yes! That is a good concept. And in fact, this is what RSX has, and
>> there it is called an ACD - Ancilliary Control Driver. It hooks into
>> the terminal driver at certain points in the processing for both input
>> and output.
>>
>> The interface is not as clean as an ACP, as this is not something that
>> can be handled at the QIO system call level, but is processing that
>> needs to happen for individual characters as they are entered, or
>> strings when they are output, which can happen for other reasons than
>> a QIO as well.
>>
>>     Johnny
>
> I would expect that, if such a facility was implemented on VMS, it would
> intercept at the $QIO level and be transparent to calling programs,
> i.e., it would look just like the existing terminal driver.

You can't really intercept at the QIO level, as you have output that 
might happen without any QIO even involved, and some input processing 
also happen before/without any QIO involved.

> I would also expect that it would execute within the context of the
> process and not as a separate process.

That I would agree with.

	Johnny