One of my companies customers runs an IPSwitch sftp server, and they have disallowed public key authentication, and require us to change our password every 90 days.The problem is that, I cannot see any way to, in advance, proactively change the password.  What happens is that when a login attempt happens after the password has expired, you get an authentication error and a prompt to change the password.  Since our systems are all automated, I need a way to change it automatically.I was thinking I'd just write something that would catch the error and initiate a script that would attempt to login, read the password prompt from stdout/stderr, and send the new password back via stdin, and I'd be all good.The problem with this approach is that the regular ssh client is using a separate tty in order to send the password prompt / etc..., so my normal stdout/stderr catching isn't working (see the answer at http://goo.gl/p1xOPu for an explanation).I may end up going the route of setting up a pseudo-tty as described in that answer, but it looks like it's pretty involved, so I figured I'd see if anyone here had any better ideas.Thanks :) 
How to programmatically change a password on an IPSwitch server using a Linux client?
linux;ssh;sftp