[SOLVED] Auto configuring a whole subnet with Expect script?

Tarikc · 03-14-2012, 12:33 PM

Hi everybody!

I google it but I did not find anything fruitful.
I use expect to auto configure a single host using ssh and run the script with crontab.

What I want to do now is that I want to use the expect script on a whole subnet 192.168.0.0/24 for example, to execute one or two commands.

Is this possible? and how?

Looking very forward to your reply.

Thanks in advance guys.

toddles13 · 03-15-2012, 03:00 AM

Depends on how your expect script works but you can always call it from a bash script.

Code:

for i in $(seq 1 1 254);
do 
<your expect script> 192.168.1.$i
done

If you bash version is more modern then you can simply use

Code:

for i in {1..255};
do
<your expect script> 192.168.1.$i
done

See the examples here.

http://www.cyberciti.biz/faq/bash-for-loop/

Tarikc · 03-18-2012, 09:19 AM

Hello toddles13,

Thank you very much for your reply.
I'm new to to making scripts with bash.

When I did this:

for i in {1..255};
do
expect -f /etc/file
done

and pointed the and in the expect file I wrote within the file:
spawn ssh user@192.168.1.$i

The action got rejected with:

can't read "i": no such variable

How can I map between the two file??
or how can I write it in the correct way?

Thank you very much for your kind help.

toddles13 · 03-20-2012, 03:12 AM

Hi Tarikc,

I have never written anything in expect before now but this works just fine.

Code:

#!/usr/bin/expect
puts "This is arg0 [lindex $argv 0]"
puts "This is arg1 [lindex $argv 1]"

Which when run

Code:

./your_expect_script foo bar

The output would be:

This is arg0 foo
This is arg1 bar

So for the bash part you would simply be

Code:

for i in {1..255};
do
/path to your expect script/your_expect_script $i
done

If we used the example expect script from above you get the following.

Code:

$ for i in {1..255}; do ./test.expect $i; done
This is arg0 1
This is arg1 
This is arg0 2
This is arg1 
This is arg0 3
..
..
This is arg1 
This is arg0 255
This is arg1

That should get you going.

If not have a look for arguments, parameters and variables, most languages will have these and there are bound to be plenty of examples around.

Tarikc · 03-20-2012, 03:54 AM

Hello toddles13,

You are the man!!
Thank you very much for your wonderful help.
It worked like a charm.

Thank you

toddles13 · 03-23-2012, 04:52 PM

No problem, glad its got you going.