Need help with Expect script for Cisco IPS Sensors, Expect sleep and quoting
This Expect script provides expect with a list of IP addresses to Cisco IPS sensors and commands to configure Cisco IPS sensors. The user, password, IP addresses, prompt regex, etc. have been anonymized. In general this script will log into the sensors and send commands successfully but there are some problems I haven't been able to solve.
Delays in prompts, Sleep timers:
1. Sometimes the script appears to send the next command before the next prompt appears in which case the correct command is skipped and the one afterwards sent and accepted. The commands usually need to be entered in order so this usually produces an error. For example Expect sends "service signature-definition sig0" and the sensor receives it but the sensor takes 5-10 seconds to provide the next prompt. The possibility of this long delay which will cause an error has forced me to insert a sleep timer after each command is sent in my loop. One problem with that is if the delay is even longer than my sleep timer I still get an error. Another problem is the script takes forever because there's a 10 second pause after every command. Is using a sleep timer the only or best solution to this problem?
Quoting, Escaping \. in Regex
2. From what I can tell in Expect if I don't quote the command "configure terminal" it's received at the IPS sensor as 2 separate commands so I have to quote it. I don't know if this is causing this problem but for some reason when I use this script the regex string 10\.1\.1\.100 ends up being sent to the IPS sensor without the backslashes 10.1.1.100 but I don't want the regular expression dot . evaluated I just want an IP address with periods i.e. with the periods escaped with the backslash. Something about my Expect script is causing this problem because when I log into an IPS sensor using ssh and copy and paste the commands into the IPS sensors manually the regex string is saved with the backslashes. I've tried removing the quotes and I've also tried double quoting and neither work. Does anyone know what I'm doing wrong here or what I could try to use Expect to send a regex string with backslashes intact?
Hello to all...this is my first post (so please go easy). :)
I feel pretty solid at expect scripting, but I'm running into an issue that I'm not able to wrap my head around. I wrote a script that is a little advanced for logging into a remote Linux machine and changing text in a file using sed.... (2 Replies)
I wrote some expect script to telnet to some device to execute some commands.Firstly,I can't get full result some time,then I try to add some "sleep" command in it.Fortunately it works.
My idea about it is that it uses sleep command to wait the result to be displayed.Am I right or correct the... (4 Replies)
At times I find the need to test that the tacacs port 49 is open.
The code below works but is painfully slow because I have to wait on the timeouts.
Examples of possible responds
router1#telnet 10.11.20.14 49
Trying 206.112.204.140, 49 ... Open
route1#telnet 10.11.19.14 49
Trying... (1 Reply)
Fairly new to the System Admin world, and this is my first post here, hoping to get some clarification.
I am using a BASH script to automate some Logfile Archiving (into .tars). The actual logfiles are accessed through an SSH, so I have used the following EXPECT sub-script within my main BASH... (8 Replies)
Hi all,
I use a bash script which use expect to connect throught ssh and run command on a cisco router. The ssh connection with expect work fine, but the first command on the cisco router failed,
I try to run the command in error by hand and it work fine... :(
the first part of the script... (2 Replies)
Hi,
Am very new to expect scripting..
Can You please suggest me how to call an expect script inside another expect script..
I tried with
spawn /usr/bin/ksh
send "expect main.exp\r"
expect $root_prompt
and
spawn /usr/bin/ksh
send "main.exp\r"
expect $root_prompt
Both... (1 Reply)
I know there are better ways to do this.
I prefer snmp. I do not have the proper perl modules loaded on the platorm. Snmp isnt loaded on the platform. Telnet is not an option. I need to write an expect script to pull cisco equipment configs.
The following code is executed once I gain... (0 Replies)
I have an expect script called remote that I want to call from inside my expect script called sudoers.push, here is the code that is causing me issues:
set REMOTE "/root/scripts/remote"
...
log_user 1
send_user "Executing remote script as $user...\n"
send_user "Command to execute is: $REMOTE... (1 Reply)
I'm fairly new to scripting so this might not be possible.
I am using Expect with Cisco switches and need to capture the string after finding the expect request. For example, when I issue "show version" on a Nexus switch, I'm looking to capture the current firmware version:
#show version
... (0 Replies)
HI all
i need to connect to about 900 cisco routers and switch to do some configs changes. the issue i am having is that half the devices have one set of username and password and the other half have another username and password. From expect or bash script i can ssh into a device and make... (0 Replies)
Discussion started by: quintin
0 Replies
LEARN ABOUT DEBIAN
autoexpect
AUTOEXPECT(1) General Commands Manual AUTOEXPECT(1)NAME
autoexpect - generate an Expect script from watching a session
SYNOPSIS
autoexpect [ args ] [ program args... ]
INTRODUCTION
autoexpect watches you interacting with another program and creates an Expect script that reproduces your interactions. For straightline
scripts, autoexpect saves substantial time over writing scripts by hand. Even if you are an Expect expert, you will find it convenient to
use autoexpect to automate the more mindless parts of interactions. It is much easier to cut/paste hunks of autoexpect scripts together
than to write them from scratch. And if you are a beginner, you may be able to get away with learning nothing more about Expect than how
to call autoexpect.
The simplest way to use autoexpect is to call it from the command line with no arguments. For example:
% autoexpect
By default, autoexpect spawns a shell for you. Given a program name and arguments, autoexpect spawns that program. For example:
% autoexpect ftp ftp.cme.nist.gov
Once your spawned program is running, interact normally. When you have exited the shell (or program that you specified), autoexpect will
create a new script for you. By default, autoexpect writes the new script to "script.exp". You can override this with the -f flag fol-
lowed by a new script name.
The following example runs "ftp ftp.cme.nist.gov" and stores the resulting Expect script in the file "nist".
% autoexpect -f nist ftp ftp.cme.nist.gov
It is important to understand that autoexpect does not guarantee a working script because it necessarily has to guess about certain things
- and occasionally it guesses wrong. However, it is usually very easy to identify and fix these problems. The typical problems are:
o Timing. A surprisingly large number of programs (rn, ksh, zsh, telnet, etc.) and devices (e.g., modems) ignore keystrokes that
arrive "too quickly" after prompts. If you find your new script hanging up at one spot, try adding a short sleep just before
the previous send.
You can force this behavior throughout by overriding the variable "force_conservative" near the beginning of the generated
script. This "conservative" mode makes autoexpect automatically pause briefly (one tenth of a second) before sending each char-
acter. This pacifies every program I know of.
This conservative mode is useful if you just want to quickly reassure yourself that the problem is a timing one (or if you
really don't care about how fast the script runs). This same mode can be forced before script generation by using the -c flag.
Fortunately, these timing spots are rare. For example, telnet ignores characters only after entering its escape sequence.
Modems only ignore characters immediately after connecting to them for the first time. A few programs exhibit this behavior all
the time but typically have a switch to disable it. For example, rn's -T flag disables this behavior.
The following example starts autoexpect in conservative mode.
autoexpect -c
The -C flag defines a key to toggle conservative mode. The following example starts autoexpect (in non-conservative mode) with
^L as the toggle. (Note that the ^L is entered literally - i.e., enter a real control-L).
autoexpect -C ^L
The following example starts autoexpect in conservative mode with ^L as the toggle.
autoexpect -c -C ^L
o Echoing. Many program echo characters. For example, if you type "more" to a shell, what autoexpect actually sees is:
you typed 'm',
computer typed 'm',
you typed 'o',
computer typed 'o',
you typed 'r',
computer typed 'r',
...
Without specific knowledge of the program, it is impossible to know if you are waiting to see each character echoed before typ-
ing the next. If autoexpect sees characters being echoed, it assumes that it can send them all as a group rather than inter-
leaving them the way they originally appeared. This makes the script more pleasant to read. However, it could conceivably be
incorrect if you really had to wait to see each character echoed.
o Change. Autoexpect records every character from the interaction in the script. This is desirable because it gives you the
ability to make judgements about what is important and what can be replaced with a pattern match.
On the other hand, if you use commands whose output differs from run to run, the generated scripts are not going to be correct.
For example, the "date" command always produces different output. So using the date command while running autoexpect is a sure
way to produce a script that will require editing in order for it to work.
The -p flag puts autoexpect into "prompt mode". In this mode, autoexpect will only look for the the last line of program output
- which is usually the prompt. This handles the date problem (see above) and most others.
The following example starts autoexpect in prompt mode.
autoexpect -p
The -P flag defines a key to toggle prompt mode. The following example starts autoexpect (in non-prompt mode) with ^P as the
toggle. Note that the ^P is entered literally - i.e., enter a real control-P.
autoexpect -P ^P
The following example starts autoexpect in prompt mode with ^P as the toggle.
autoexpect -p -P ^P
OTHER FLAGS
The -quiet flag disables informational messages produced by autoexpect.
The -Q flag names a quote character which can be used to enter characters that autoexpect would otherwise consume because they are used as
toggles.
The following example shows a number of flags with quote used to provide a way of entering the toggles literally.
autoexpect -P ^P -C ^L -Q ^Q
STYLE
I don't know if there is a "style" for Expect programs but autoexpect should definitely not be held up as any model of style. For example,
autoexpect uses features of Expect that are intended specifically for computer-generated scripting. So don't try to faithfully write
scripts that appear as if they were generated by autoexpect. This is not useful.
On the other hand, autoexpect scripts do show some worthwhile things. For example, you can see how any string must be quoted in order to
use it in a Tcl script simply by running the strings through autoexpect.
SEE ALSO
"Exploring Expect: A Tcl-Based Toolkit for Automating Interactive Programs" by Don Libes, O'Reilly and Associates, January 1995.
AUTHOR
Don Libes, National Institute of Standards and Technology
expect and autoexpect are in the public domain. NIST and I would appreciate credit if these programs or parts of them are used.
30 June 1995 AUTOEXPECT(1)