Bash/Expect Script for SSH

Question

I am new to Expect and scripting in general. I am trying to make a few scripts to make my life a bit easier when pulling network device configurations. I managed to create a

Answer 1

This is a Perl version for this issue:

Install instruction:

cpan Expect

This script works perfectly for my needs.

Parameter 1: Connection string (example: admin@10.34.123.10)
Parameter 2: Clear text password
Parameter 3: Command to execute

#!/usr/bin/perl
use strict;

use Expect;

my $timeout = 1;

my $command = "ssh " . $ARGV[0] . " " . $ARGV[2];

#print " => $command\n";

my $exp = Expect->spawn($command) or die "Cannot spawn $command: $!\n";
$exp->raw_pty(1);

LOGIN:
$exp->expect($timeout,
        [ 'ogin: $' => sub {
                     $exp->send("luser\n");
                     exp_continue;
                }
        ],
        [ 'yes\/no\)\?\s*$' => sub {
                    $exp->send("yes\n");
                    goto LOGIN;
                }
        ],
        [ 'assword:\s*$' => sub {
                    $exp->send($ARGV[1]."\n");
                    #print "password send: ", $ARGV[1];
                    exp_continue;
                }
        ],
        '-re', qr'[#>:] $'
);
$exp->soft_close();

Answer 2

Or use set ip [gets stdin] to the IP address from the user input.

For example,

puts "Enter your IP address\n"
set ip [get stdin]

Use this in spawn. We can do the same for multiple IP addresses using a loop -

spawn ssh $ip -l admin

Answer 3

I would do this (untested):

#!/usr/bin/expect -f

set logfile "/home/text.cfg[clock format [clock seconds] -format %Y%m%d]"
close [open $logfile w]         ;# truncate the logfile if it exists

set ip_file "list.txt"
set fid [open $ip_file r]

while {[gets $fid ip] != -1} {

    spawn ssh $ip -l admin
    expect "Password:"
    send "password\r"

    expect "admin@"
    send "set cli pager off\r"

    log_file $logfile
    send "show config running\r"

    expect "admin@"
    log_file 

    send "exit\r"
    expect eof

}
close $fid

Notes:

• I removed all your comments for brevity
• use \r to simulate hitting enter when you send commands.
• I assumed you only want to log the "show config running" output
• use expect eof after you send "exit"

Answer 4

A possibility is to pass the IP address as a parameter in your Expect script:

set host_ip [lindex $argv 0]

and then make a shell script, calling your Expect script inside a while loop:

ips_file="list.txt"

while read line
do
    your_expect_script line
done < $ips_file