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I know questions like this have been asked before, and I have read them all (that I found).

The problem I have is that we have an embedded linux device that we can log into for debug purposes by doing the following:

ssh root@name

Then the password is anything (I usually just hit enter). I don't want to change anything on the embedded device/linux. But I do want to be able to (as part of my script) ssh into it.

My research has shown me that the following can be used (this is copied from another post):

#!/usr/bin/expect -f
spawn ssh
expect "assword:"
send "mypassword\r"

However with my version of Ubuntu (10.04) I don't have spawn or send commands. I was able to install the "expect" command with sudo apt-get install expect.

Does anyone have a solution? is it possible to install these commands, or is there another way to ssh and get past the "password" step?

Thanks :)

------------- EDIT -----------------

I think I am starting to understand the issue I am having. I have a script that starts with:


Then later I am trying to do:

spawn ssh
expect "assword:"
send "mypassword\r"

I did not realise that you needed explicitly the:

#!/usr/bin/expect -f

At the start of the script. so I have had to move my code into a seperate file which contains only and exactly:

#!/usr/bin/expect -f
spawn ssh
expect "assword:"
send "mypassword\r"

... sorry for the mis-understanding on my part, but people answers helped me to twig what I was doing. This is not quite ideal for me as I wanted to pass parameters in to open different ssh connections and I can't pass in parameters to this script starting with "expect -f" :(

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migrated from Sep 18 '13 at 11:25

This question came from our site for professional and enthusiast programmers.

Is there any reason you can not use a ssh key? Such as not being able to write to /root? If not please read this. – Hennes Sep 18 '13 at 11:27
and the spawn and send are internal cmds to expect. Once you have it installed correctly, you should be able to above script. Good luck. – shellter Sep 18 '13 at 11:28
@Hennes Actually in this case "yes" there is a reason I can't do that. The embedded linux file system is read only (proceted). Though I can unlock this everything will be over-written when we install the next version (which is very often :( ... but the solution looks good for a future use :) – code_fodder Sep 18 '13 at 11:50
I expect as much when I read "embedded". Otherwise I would just have commented "Upgrade it to something more modern and use ssh keys". (Q: Overwritten as read from flash and unpacked to RAM or union FS?) – Hennes Sep 18 '13 at 11:52
@shellter Hmm... as I mentioned I did sudo apt-get install expect. But send still does not work. I get error like program 'send' can be found in the following packages: mailutils-mh, nmh. What am I doing wrong there? – code_fodder Sep 18 '13 at 11:53
up vote 2 down vote accepted

I think you're trying to run your script as a shell script. After installing expect, run your script like this:

expect -f scrip.exp

If you can't install expect as a normal user, try installing its binaries in one of your directories in $HOME e.g. $HOME/opt/ and call expect from there, although it would depend on your system on how you could manipulate LD_LIBRARY_PATH to add another directory for searching dynamic libraries.

An example of embedded expect:



expect <<EOF
spawn ssh "${USER}@${SERVER}"
expect "assword:"
send "${PASSWORD}\r"

Run with

bash user server password
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Thanks for that, your reply helped my to understand what I was doing wrong. Please see my edit. – code_fodder Sep 18 '13 at 13:07
@code_fodder Please see my update. – konsolebox Sep 18 '13 at 13:13
Yeah, thats a nice touch, thanks for that! – code_fodder Sep 18 '13 at 14:35

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