Summary
Expect is known primarily as an indispensable application for system administrators. Amazingly enough, it is, at its heart, Just Another Tcl Extension (JATE).
Description
People use Expect to automate interaction with non-GUI (and typically non-cursor-controlled, even though a persevering Expect programmer can tackle them, too) applications that prompt the user for input.
Examples of commands that often appear in Expect scripts are the Unix passwd, ftp, telnet, ssh, sudo, and command-line shells. Expect is the natural answer for those who want to automate password changes, periodically update FTP sites, manage Cisco routers, or check the statuses of a collection of remote systems by logging in.
What: Expect
Where: http://expect.sf.net/
http://expect.nist.gov/
http://expect.nist.gov/FAQ.html
http://expect.nist.gov/scripts/
ftp://ftp.nist.gov/mel/div826/subject/expect/
http://prdownloads.sf.net/expect/slavedrv1.1.zip
http://phaseit.net/claird/comp.lang.tcl/expect.html
Description: Expect is a scripting language to interace with programs
such as FTP, telnet, fsck, and others that normally cannot be
automated from a shell script. Think of it as providing the means
to 'remote control' other programs. It is thus also good for
automating program exection on remote systems, and providing the
means to creating Tk interfaces on top of other, non-GUI, programs
V5.x is Tcl 7.x compatible.
The version on liv, while not from the author, is a set of source
modified to be used with tclX, BLT, and TkSteal (unmaintained).
V5.28 (the tar.gz version) is Tcl 8.0 compatible.
This package will also build expectk, which allows one
to write Tk interfaces to the above types of programs.
The version at berkeley is a release of Expect for Windows NT,
which includes patches to Tcl to allow fileevent to work
for pipes and serial ports. It does not work for Windows 95.
Check its web page for info on the latest development snapshots.
The url for a version of Expect 5.25/Tcl 7.6 for Japanese Tcl
is mentioned above.
The slavedrv code mentioned above is an attempt to port
a recent version of expect to recent version of Windows.
It may not have all the expect functionality.
Version 5.44.1 of Expect, compatible with Tcl 8.5,
is also available from the SF.net CVS repository.
Updated: 8/2009
Contact: See the web sites
Obtaining
The current maintenance of the package can be found at expect.sf.net , with access to the CVS available via sf.net's cvs repository.
Expect is part of the ActiveTcl Batteries Included distribution on Unix and as of 2005, the Windows version is available via ActiveTcl as well [L1 ].
Documentation
- man pages
- FAQ
- BOOK Exploring Expect
- the bible of the Expect world
- official website
- supplies sources and considerable history, background, and instruction. It does fail to mention, though, recognition of Expect as one of the 100 most important publications of NIST's first century. Note that the warning regarding expect 5.44 on that page is seriously out of date. The CVS 5.44 version linked to below is fine (and needed to build against Tcl 8.5).
External Resources
- Expect External Resources
- gives pointers to some wiki-external Expect material
- Expect references of interest to Cameron Laird
- some notes by CL
Tools
- expect-lite
- Written in expect, it is designed to directly map an interactive terminal session into an automation script
See Also
- Expect FAQ
- Expect Hints and Tips
- Expect Examples
- Expect Tutorials
- Debugging Expect programs
- Remote input-output with Expect
- Secure expect
- Expect for languages other than Tcl
- Most programmers don't know what Expect can do for them
- I am new to Expect
- Event-oriented Expect
- Expect vs. Tcl
- Network programming with Expect
- Expect and Tclkit
- Expect and choice
- It seems like Expect is not actively developed
- overlay
- handling of ANSI terminals using Expect
- send special characters
- Stubsification of Expect
- An example wherein Expect controls a pager
- "expect_out(buffer) has the content of the previous send"
- Calc_Object
- How Expect can capture the exit code from a remote command
- Expect for Windows
- Expect for languages other than Tcl
- Checking your IMAP mail with Expect
- How to access the result of a remote command in Expect
- Many people who think they need Expect do not need Expect
- Expect's frequently-made mistakes
- How Expect sees function keys
- How to send escape characters through Expect
- Pipes vs Expect
- expectk
- expect in pure tcl
- expect4j
- provides a certain level of expect's functionality to the Jacl / Java programmer. Package author Justin Ryan reports on the TclJava mailing list : I've successfully ported a 100K tcl script based on expect to tcljava, without any changes, by just using expect4j.
- How do I get the result of a remote command when I have to pass through a third host?
- Don't Expect to sleep
- How do I execute 'grep' on a remote machine and receive the result?
Articles
- Writing a Tcl Extension in Only Three, no Four, no Five, no 7 Years
- Don Libes' memoir on the joys of writing "simple" tools to get stuff done.
- Expect Success , Cameron Laird 2003
- is, for Kim Richert, "the best Expect article I've read". alternate
- Expect Exceeds Expectations , Cameron Laird, 2002
- a short introduction with minimal examples alternate
- Expect: The Firefighter's Friend , Cameron Laird, 2002
- alternate
- Unknown Expect , Cameron Laird ,2004-02
- seven little-known facts about expect that may help you use it more efficiently
- Test-driven Development, Expect, and Systems Administration , Cameron Laird ,2003-12-15
- Expect Tutorial
- Using Expect to Configure Cisco Routers , Clay Lin ,1999
- "... the entire task would take about a month for two people ... What used to take us a month now takes about an hour to finish completely and accurately."
- Expect plays a crucial role in network management , Cameron Laird, 2007-07-31
- Expect , Keith Waclena ,1994
- a 5-minute tutorial
- Automating Tasks with EXPECT ,Vinnie Saladino ,1998
Example Scripts
- ftp-inband
Standard Sample Scripts
- kibitz
- mkpasswd
- multixterm
- passmass
- unbuffer
- xkibitz
(todo: fill out)
Misc
LV: Note that expect is also a command that is a part of the expect extension; see the expect source distribution for the doc.
Lars H: Also note that in the latter sense, expect is a powerful control structure (pretty much an automaton, is it not?).
srinadh 2009-10-08 10:41:28: I have an expect program. Sometimes it produces a core dump. How do I see core dump backtrace? Thanks
AMG: Use gdb.
susja 2010-11-12 14:05:18: I have a simple task: run autoexpect program to automate telnet. I was able to do it on my Solaris box but I am stuck on my Windows XP box. Here's what I did:
- downloaded expect-5.43.tar to my local drive, untar it and have Expect located at C:\.... . I tried to execute 'autoexpect' but it says: "'autoexpect' is not recognized as an internal or external command"
- I installed ActiveTcl 8.5.9. Successfully ran 'teacup install Expect'.
- Here I'm blocked: how now I could execute autoexpect program?
thanks in advance
bodangly 2011-12-13 18:47:18: The above question is old and the user likely found the answer however for reference, the PATH environment variable needs to have the location of the autoexpect program appended to it.