Xref: utzoo unix-pc.general:5006 comp.sys.att:9002
Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!shelby!apple!usc!cs.utexas.edu!yale!ox.com!umich!sharkey!cfctech!ttardis!rlw
From: rlw@ttardis.UUCP (Ron Wilson)
Newsgroups: unix-pc.general,comp.sys.att
Subject: Re: Extra 3B1 Phone features?
Message-ID: <2496@ttardis.UUCP>
Date: 13 Mar 90 22:07:42 GMT
Organization: Gallifrey
Lines: 17

In article <5131@emory.mathcs.emory.edu>, km@mathcs.emory.edu (Ken Mandelberg) writes:
>phone program that allows:
>
>2) demon dialing: Redials a busy number until it answers.
>-- 
>Ken Mandelberg      | km@mathcs.emory.edu          PREFERRED

Demon dialing isn't really practical on the UNIX-PC internal dialer: the
internal dialer does NOT have busy detect - you end up listening to 30 secs
of the busy signal, then it times out (it assumes that you have picked up the
handset by then, and releases the line) - in theory, a program could check if
the handset was "off hook" when the dial(3) (or ioctl(2)) function returns
after dialing: if the handset was still "on hook," the program could redial.

But, as I said, the dialer doesn't have a busy tone detector, so it would
keep your phone line busy for 30 second intervals at whatever time period
you were retrying the number.