Exploring Expect

Exercises

1. Write a script that retrieves an FAQ. First the script should attempt to get the FAQ locally by using your local news reading software. If the FAQ has expired or is not present for some other reason, the script should anonymously ftp it from rtfm.mit.edu. (For instance, the first part of the Tcl FAQ lives in the file /pub/usenet/news.answers/tcl-faq/part1.) If the ftp fails because the site is too loaded or is down, the script should go into the background and retry later, or it should send email to [e-mail] in the form:

      send usenet/news.answers/tcl-faq/part1

2. Write a script called netpipe that acts as a network pipe. Shell scripts on two different machines should be able to invoke netpipe to communicate with each other as easily as if they were using named pipes (i.e., fifos) on a single machine.

3. Several of your colleagues are interested in listening to Internet Talk Radio and Internet Town Hall. ^[58]Unfortunately, each hour of listening pleasure is 30Mb. Rather than tying up your expensive communications link each time the same file is requested, make a cron entry that downloads the new programs once each day. (For information about the service, send mail to [e-mail].)

4. The dialback scripts in Chapter 1 (p. 4) and Chapter 16 (p. 347) dial back immediately. Use at to delay the start by one minute so that there is time to log out and accept the incoming call on the original modem. Then rewrite the script using fork and disconnect. Is there any functional ...