Exploring Expect

Rating:
Summary: being the only book isn't a Good Thing
Review: a quick rundown of what I needed to do:

We have RSA fobs that have an algorithmically changing number displayed on them. Logging into a remote machine requires that we check the fobs readout for the current number. Needless to say, it's not possible to automate this part, but all of the other parts are automatable. It took me a long time to find how to "exit out of the automation, and jump back into it", and this is likely one of the more useful features of expect.

As others have said, the structure of this book is not very predictable, and the parts that you wish would be more detailed, are the ones that lack the most info (the actual expect script command, and it's branching structure is only discussed to "one level deep").

In general, you use expect to kludge together apps...so in a sense, expect has grown to be somewhat of a kludge in and of itself. It's a necessity in the UNIX world, but don't expect to master it fully for a long time.

Rating:
Summary: Very promising - both the tool and the book
Review: Although I've just started reading the book ( first 5 chapters ) it already impressed me with intensive depth the author covers all related topics. Sure, Expect is great ( and thank's for this tool, Don ! ) but this book isn't only about Expect - it's about almost *everything* you'll ever need to program interactive scripts using Expect. It talks about Tcl, zombies in UNIX, regular expressions ( really *in depth* talk ), "\r\n" vs "\r" and "\n" and hell knows what else ( fortunately, I have many more to read ) ! It reminds me the "Data munging with Perl" collecting the vast collection of data processing techniques using Perl.

A pleasure to read. Don is a professional and experienced programmer and a nice writer. After I finish it I'll probably have even more to say ..

Rating:
Summary: A completely different tool
Review: Expect is completely unlike any other tool I have ever used. Think of any language you've used and how long it would take to: write a program that can update 1000 user passwords on 20 different machines; make two chess programs play each other; connect two users to the same shell program and type at the same time; allow you to rewrite the command arguments to any command line tool?

Expect really does make all these things trivial. It takes a lot of patience to master this tool though; Tcl is a very unforgiving and terse language. I've done things in Expect that I never thought were possible: I scripted Minicom (a modem term program that uses ncurses) to answer a phone after 7 seconds, and either: receive a zmodem file or send a login prompt. Then hang up the modem and wait again. Try that in a shell or systems language!

It's unfortunate that Expect is such a radically different beast and takes so long to understand; every person running regression tests or doing systems administration will benefit from this book. While it may not be great for just "looking up" things, search Usenet for all of the author's posts (comp.lang.tcl) and his answer is almost always, "This is on page XXX of the book." Because the book really does cover everything Expect does!

Rating:
Summary: Reads like a seedy novel, no organization, helpless index.
Review: I've come to "expect" computer books to deliver information in succint form, followed by useful examples. Instead, this book reads like a novel. The only way to understand anything is to read from start to finish. And without a companion TCL reference it's hopeless. Many keywords are used and discussed in passing, but never defined.

The index randomly references word matches within paragraphs instead of topical sections. (Someone must have used a blind "find" function since the index was obviously an afterthought.)

A language with such a narrow purpose and small command set shouldn't require nearly 600 conversational pages. I admit I didn't give this book much of a chance, but as my only available reference to this subject, I am very frustrated. I loved the O'Reilly Perl book. How could they have strayed so badly with this one?

Rating:
Summary: Nice reference to have
Review: The good thing about this book is that it gives one a basic back ground of TCL before delving into Expect which, makes it an excellent "quick" reference book to have on the shelf. The only drawback I can really think of is that it is not extensive as it should be to make it an exhaustive reference guide.

Nice book. Worth the money you pay.

Rating:
Summary: Expect ist great. Only book about Expect
Review: The only book about Expect, so one cannot compare it to others. But it serves it's purpose. Expect is a Tcl extension with about forty extra commands and variables to handle interactive processes from a script. This capability is unique to that Language. With ExpectK one can use Tk as well. I read the book in three nights, because it was such a help to my sysadmin tasks on UNIX. But despite all my propaganda, only one other person picked it up for writing a chat robot. The book is a must for every UNIX admin, if he is free to use the languages he likes, which is, unfortunately, not the case in many banks.

Rating:
Summary: No alternatives
Review: When I discovered Perl I though it's a quick and dirty way to automate admin tasks. I was wrong. The really quick and dirty way is Expect. Expect works like Helpdesk hotline. You call them and they ask you what you see and tell you what you should type. Sometimes you just have no alternatives especially if you're short on time. But the language is pretty tricky (e.g. if you want to look for '$' in regexp, you should use '\\\$' pattern, etc) and I couldn't learn it using just examples included in the distribution package. Then I spent some time searching for the good tutorial and this book was the best I found. Expect is surprisingly poorly documented and I didn't find any other books about it. There are some articles in the Internet, but usually they don't give you the whole picture. This book includes many examples, easy stuff in the beginning to get you started and very advanced in the end. That's everything you need to learn expect and it's written pretty friendly. In some places it's very informal but not too much.