Re: [Expectperl-discuss] Expect and passwd

[Austin S. <te...@of...>]

On Mon, Sep 09, 2002 at 12:17:41PM -0600, Walls Rob W Contr 75 CS/SCBS wrote:
> I removed the explicitly added \n from the password ->send string.  Now
> debug reports Sending '1derful^J' to spawn id(3) instead of the
> '1derful\n\012' it was sending. However, the intermittent hang still occurs.
> When things hang, Expect receives the password instead of 'New password'.
> That is:
> Waiting for new data ...
> 1derful
> 
> instead of:
> 
> Waiting for new data ...
> New password:
> It's like the answer arrives before the question is asked...

	Typically a well written password program, i.e. one that asks
for a password, should turn echoing off before printing the 'Password: '
prompt. Some programs, such as /bin/passwd included w/ redhat 6.2, send the
password prompt, and then flush the pty buffer as they set '-echo' on the line.
This creates a race condition that may be experienced maybe 2-5% of the time.
	I would first turn on $Exp_Internal and make sure you are expecting
a space after 'New password:', if one is sent. Once that is correct and you
are 100% sure you're matching the correct prompt, sleep(1) before
sending the password. That way you will give the program a chance to set
echoing off and get ready to receive the data well before you send it.

	Austin