Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!eecae!netnews.upenn.edu!rutgers!cbmvax!uunet!ispi!jbayer
From: jbayer@ispi.UUCP (Jonathan Bayer)
Newsgroups: comp.mail.uucp
Subject: Re: Questions on L.sys file entries
Summary: Answers to L.sys questions
Keywords: L.sys expect send uucp questions expect/send
Message-ID: <452@ispi.UUCP>
Date: 9 Feb 89 15:48:01 GMT
References: <1155@naucse.UUCP>
Distribution: usa
Organization: Intelligent Software Products, Inc.
Lines: 85



In article <1155@naucse.UUCP> root@naucse.UUCP (System Administrator) writes:
>I've got a few questions for any/all uucp gurus out there.  We've been
>having some problems with connecting to our only uucp neighbor, and I

	The following answers are assuming HDB UUCP.  There will be
minor differences from the old UUCP.


>Regarding entries in the L.sys file (expect/send sequences):
>
>1. I read that the expect algorithm looks at the LAST PART of the
>   incoming text, when comparing strings.  But suppose the string I
>   want to match has a new-line in it?  How do I express this in
>   my expect string?  Example:

>   fictitious incoming text:    type your name:\n

>   My sequence  "name: myname"  won't work, since the string "name:"
>   is NOT the last thing received: there's a newline in there, too!
>   Are carriage-returns and newlines ignored by the algorithm, or can
>   I put something like "\n" in my expect string?  What if it's also
		^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
			yes, but not needed.  If your sys entry has

				name:

			as the text it is looking for, it will send the next
			sequence of text as soon as it sees the "name:"

>2. With keywords like PAUSE and - specially interpreted in my expect/
>   send sequences, how can I force these to be considered part of the
>   text, if I needed to do so?  Can I escape them?  How?  If I escape
>   things with a backslash (\) like usual, is \\ considered a back-
>   slash character?

	It will depend on your uucp.  The \\ is interpreted as \  
	One thing you can do is to make the first character of the word
	as an octal digit.  For example, PAUSE could be put in as:
		\120AUSE

>3. How does the algorithm decide that the expected string has not
>   come in?  Does it have a timeout value of some sort?  If so, how
>   long?  Does it "timeout" that long after no more text is received,
>   or just after that time period is up (regardless of incoming text)?

	Yes, there is a timeout, typically about 30 seconds.

>4. While data is steadily coming in, does the expect algorithm look
>   at snapshots of it, even though it's incomplete?  Example:
>
>   fictitious incoming text:	Enter password:
>
>   will the sequence   "sswo myname"  ever succeed because that was
>   the last thing in the buffer at one point?  Of course this would
>   be VERY unreliable, but could it happen?

	According to the docs, yes.

>5. Is the text-to-send sent the instant the expect algorithm sees
>   what it's been looking for, or is there a pause of one or more
>   seconds?

	It is sent almost immediately.  If you want a pause you could
	put in a \d (delay for 2 seconds) in the script.
>
>The manuals just leave me fuzzy on details.  I really appreciate any
assistance you all can give me on this subject.  Thank you.


Do yourself a favor and pick up a copy of the Nutshell handbook:

	Managing UUCP and Usenet

It answers all questions in a readable format.


JB

-- 
Jonathan Bayer			      Beware: The light at the end of the
Intelligent Software Products, Inc.	      tunnel may be an oncoming dragon
19 Virginia Ave.				...uunet!ispi!jbayer
Rockville Centre, NY 11570  (516) 766-2867    jbayer@ispi.UUCP