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From: thomas@nac.dec.com (Matt Thomas)
Newsgroups: comp.unix.ultrix
Subject: Re: Logging dlogin session to VMS
Message-ID: <7256@shlump.nac.dec.com>
Date: 5 Jan 90 22:55:14 GMT
References: <9225@cbmvax.commodore.com> <1995@eric.mpr.ca> <7225@shlump.nac.dec.com>
Sender: news@shlump.nac.dec.com
Reply-To: thomas@decwrl.dec.com
Organization: Digital Equipment Corporation
Lines: 45

In article <9225@cbmvax.commodore.com>, grr@cbmvax.commodore.com (George
Robbins) writes:
> In article <7225@shlump.nac.dec.com>, I wrote writes:
> > I could change dlogin to set the logfile to be unbuffered but that
> > would be at the cost of slowing down dlogin.  Or maybe fflush the
> > logfile once dlogin has been idle for 30secs or so.  (which would
> > be easy to tie into the select call).  And/or when you escape to the
> > dlogin command menu?  Any other ideas?
> 
> Opinion:
> 
> It seems to me that the -l switch is used so infrequently that setting the
> log to unbuffered or doing a fflush after each time your see that you have
> written a line terminator to the terminal output wouldn't really have any
> serious performance impact.  You might try it and see if there's any
noticable
> slow down.

I'll take a look at it.

> BTW, you might want to think about what dlogin is doing for input and output.
> It appears to at least look at stdin for input but opens /dev/tty for output.
> This makes it inordinatly difficult to drive from a script or pipe the output
> to something else as compared to copying the stdin/stdout descriptors...

dlogin does check stdin to make sure that it's a tty but doesn't reopen
stdin/stdout
or stderr.  This was done in the far distant past before I joined the group.
My guess for the reason for this is that there is no way to synchronize
the input
to the requests from the remote node (what does flush typeahead do?
which is the
first thing VMS does) and that a using pty would be best.  I don't
strong feelings
either way but it does seem to be a reasonable argument.

Just checked the sources, dlogin just prints out a misleading error message.
It does a itatty(0) but prints

	"warning - controlling terminal is not a physical terminal".
-- 
Matt Thomas                     Internet:   thomas@decwrl.dec.com
DECnet-ULTRIX Development       UUCP:       ...!decwrl!thomas
Digital Equipment Corporation   Disclaimer: This message reflects my own
Littleton, MA                               warped views, etc.