Tcl/Tk - More on Expect

Tcl/Tk module T242

Related technical and longer articles

Articles and tips on this subject		updated
3448	Checking all the systems on a subnet, using Expect and Tk There are times that we want to check the connectivity of all the systems on our subnet - to see which machines are present, and which are not. Pinging them one at a time is a bit slow, but pinging them all at once in a simple script sets up too many connections and the script is likely to fall over. ...	2011-09-18
3009	Expect in Perl - a short explanation and a practical example Around 20% of delegates on our Tcl Courses are using Tcl because of the Expect package that extends it to "choreograph" interaction with other systems and processes, and yet the Expect module in Perl (Expect.pm) is decidedly niche and we cover it on our Perl for Larger Projects course only on request. ...	2010-10-22
2475	Quick easy and dangerous - automated logins via Tcl / Expect Let me start with a security warning. Passwords and firewalls are there to make it difficult for unauthorized users to get through / at systems, and if you write a script which automates passwords and multi-hop telnet and ssh logins to make it quick and easy for you to get over all the hurdles you are ...	2009-10-24
1531	Expecting a item from a list of possibles There are times (and they're quite frequent!) that I'm asked a good question that's so good it's worth sharing the answer. Actually, that makes up a fair proportion of my inspirations for this spot, such as today's. In Expect - the command line automation tool of the Tcl language - you can tell the ...	2008-02-05
1475	Tcl/Tk - updating your display while tasks are running Let me make two statements: 1. When you are popping up a new window from your program, the very last thing you want to see happen is for the window to gradually appear, with bits of it being resized as it comes on the screen - not only is such an operation irritating on the eye, but also it's burning ...	2007-12-16
1411	Buffering of inputs to expect, and match order If you're using the expect command to wait for one of a series of inputs within your expect program, information will be checked in the program's internal buffers inthe following order: a) Any string that matches expect_before will be found b) Matches to each of the possible patterns in expect in turn c) ...	2007-10-30
1173	Cheat Sheet / Check list for Expect maintainers Programming in Expect can be very different (and more challenging) than conventional programming. Rather than write code (structured, if you like) through a series of events, you'll do better to start off with a co-operation diagram of the process that you want to automate [[For the newcomer, Expect ...	2007-05-03
435	Expect for Windows I've just noticed on the Activestate site that "the ActiveTcl distribution now includes Expect for Windows. A license is no longer required ....". At face value, that looks like excellent news! One of the big uses of Tcl and Tcl/Tk is in the automation of processes / programs that are designed to ...	2006-06-05

Examples from our training material

chammy	Automated Logging In
engineer	send_human in expect
immortal	Catching signals in expect
multisigs	Trapping multiple signals in Expect
pingabout	Expect to run ping on a named host; able to switch host during run
rupple	Expect - run rup on a named host
sslo	Send slow example - expect
subnet_test	Check a subnet for pingable systems
tcenhance	Telnet wrapper using interact; provides filtering too
tctel	Telnet wrapper using interact
typist	Second example of expect's "send_human" command.

Pictures

Network testing through Expectk

Background information

Some modules are available for download as a sample of our material or under an Open Training Notes License for free download from [here].

Topics covered in this module

Expecting from the user.
Using expect and send for user communication.
Waiting for the user or for a process.
More facilities.
Defining default expect patterns.
Humanesque input.
Sending Specials.
Signals.
Receiving signals.
Sending Signals.
Command line options.
Interact.
Filtering throughput.

Complete learning

If you are looking for a complete course and not just a information on a single subject, visit our Listing and schedule page.

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