Sponsored Content
Top Forums Shell Programming and Scripting Expect Script square bracket dollar prompt Post 302400732 by Ikaro0 on Thursday 4th of March 2010 03:32:40 AM
Old 03-04-2010
Hi,
Thanks a log for the quick replay but I think it is not good cause it sems that no matter what if founds it continues.

I'll explain better the situation:

Environment: Production, servers don't allow for root ssh connections.

The need that I had was to create a script for creating users on all the servers (more than 200 Unix,Linux)

What I've done so far is:

I had created a script that login each server with gets "user login name", "user password" and "user to be created"

The the script reads from a file, the servername and rootpassword and apss all the information to the expect script in form of parameters

The expect script uses the parameters ($0 $1.....) for connecting to the servers as the entered user, puts the password, changes to root, sends useradd....."user to be created" and then logs of and continue to the next one.

The thing here is that the script works but due to differences on the servers I need to cover all the posibilities for it to work fast and without error.

for login I had the following at the script:

spawn ssh $username@$ipaddr
match_max 100000
Code:
expect_after {
    eof {send_log "\nEXP-ERROR---No se ha podido conectar con $ipaddr\n" ; exit 1 }
}
expect {
        timeout {send_log "\nEXP-ERROR---TIMEOUT No se ha podido conectar con $ipaddr\n" ; exit 1 }
        "(yes/no)?"   {send "yes\n"}
        "*?assword:" {send "$userpass\r"}
        }

and then :

Code:
expect  {
        ".*\?"      {send "\n";sleep 1;send "\n"} ----for servers that ask for oraclehome
        ".*\$"          {send_log "\nEXP-EXEC---Login correcto\n"}
        "*?assword:"    {send_log "\nEXP-ERROR---Password de usuario $username incorrecto o usuario inexistente en $ipaddr" ; exit 1 }
        }

because I set timeout to -1 the script waits for ever when it logs into a server with the prompt "[whatever]$"

but putting the timeout to 5(for example) I pass (waiting) the $ paths and after entered "su -" and password, it recognise well the "[whatever]#" prompt for root and don't wait at all, sending the useradd command in no time.

Thanks a lot
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Extract string in square bracket

Hi Input text is some message some message some message Expected output is main value1 value2 value3 Any idea how to above values in square brackets using shell scripting? many thanks. (3 Replies)
Discussion started by: hnh
3 Replies

2. Shell Programming and Scripting

Expect, save to file and remove before prompt

I have an Expect script which works very well. It logs into my remote routers and runs some commands and then to the next until finished. I need two things, first I need to save the output to a file from where the log_user 1 begins. expect << EOF set timeout 15 #set var "exit " match_max... (1 Reply)
Discussion started by: numele
1 Replies

3. Shell Programming and Scripting

Group on the basis of common text in the square bracket and sorting

File A 99 >ac >ss >juk 70 >acb >defa 90 >ca 100 >aa >abc >bca 85 >cde 81 >ghi >ghij 87 >def >fgh <ijk 89 >fck >ghij >kill >aa The given output shud be 100 >aa >abc >bca 87 >def >fgh <ijk 89 >fck >ghij >kill >aa (2 Replies)
Discussion started by: cdfd123
2 Replies

4. Shell Programming and Scripting

Handling SQL prompt through Perl expect module

Hi All, I have a doubt whether expect module in perl will work in SQL prompt or its applicable only for shell prompt ? Thanks, Arun V (2 Replies)
Discussion started by: arun_maffy
2 Replies

5. Shell Programming and Scripting

ksh, difference between double bracket and single bracket

Can somebody tell me the difference between double brackets and single brackets, when doing a test. I have always been acustomed to using single brackets and have not encountered any issues to date. Why would somebody use double brackets. Ie if ] vs if Thanks to... (2 Replies)
Discussion started by: BeefStu
2 Replies

6. Shell Programming and Scripting

Expect doesn't recognize a password prompt

Hi. Here is beginning of my script #!/usr/local/bin/expect -- set timeout 15 spawn /usr/local/account.sh -n modify expect "Password:" {send "mypassword\r"} But due to some terminal control sequences (or something else, dunno exactly) my password prompt is looking like this: and expect... (3 Replies)
Discussion started by: urello
3 Replies

7. Shell Programming and Scripting

Doubt with regex to replace square bracket

there is a word "welcome" output should be "welcome\ i am using regsub to add backslash "\" in place where ever i find square brackets (open or close).. But i am not getting it... pls help out.. set a {welcome} set d (5 Replies)
Discussion started by: Syed Imran
5 Replies

8. Shell Programming and Scripting

Expect prompt extending to next line

Hi guys, I am trying to install a software which is a shell script. I am using expect to do the silent installation. There is a strange line during the installation of the software like this below. The prompt goes to the next line. ENTER AN ABSOLUTE PATH, OR PRESS <ENTER> TO ACCEPT THE... (0 Replies)
Discussion started by: kapkap
0 Replies

9. Shell Programming and Scripting

Expect script not expecting the password prompt

I have a script that does an SSH into a remote node. It should expect the prompt and send the password. #!/usr/bin/expect set user ; set pass ; spawn ssh $user@E-Internal expect { -re "RSA key fingerprint" {send "yes\r"} timeout... (1 Reply)
Discussion started by: Junaid Subhani
1 Replies

10. Shell Programming and Scripting

Dollar symbol in Shell Script Variable

Hi, I am working on PGP encryption. I am getting public keys from some file. One of the key has dollar sign in it "$" Example: "abc$123" echo 'passphrase='$passphrase --> Giving correct value abc$123 But if I use $passphrase in PGP command getting Invalid passphrase error. If I... (10 Replies)
Discussion started by: Sreehari
10 Replies
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)
All times are GMT -4. The time now is 10:50 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy