Expect in Alias - bash

Question

I am using a Bash alias that allows me to shorten the SSH command in order for me to log into my routers. Quite trivial, but a time saver! What I would now like to do is take this a step further and fully automate the logging-in of the routers.
For example in my ~/.bashrc file I have the following entry:
sshFuncB()
{
ssh -o StrictHostKeyChecking=no superuser#$1 - | /usr/bin/expect<<EOF
set timeout 5
set send_human {.1 .3 1 .05 2}
expect {
"password: " { send -h "MYPASSWORD\r" }
"No route to host" { exit 1 }
timeout { exit 1 }
}
set timeout 2
sleep 1
expect {
"N]?" { send "y\r"; exp_continue }
timeout { exit 1 }
}
expect eof
EOF
}
alias z=sshFunc
However, when I type z myrouterhostname this does not give the desired output. I must find a way to start the SSH connection and have expect automate logging in before returning control to user.
Any ideas?

Answer 1

This can be done as follows,
sshFuncB()
{
expect -c "
spawn ssh -o StrictHostKeyChecking=no superuser#$1
set timeout 5
set send_human {.1 .3 1 .05 2}
expect {
\"password: \" { send -h \"MYPASSWORD\r\" }
\"No route to host\" { exit 1 }
timeout { exit 1 }
}
set timeout 2
sleep 1
expect {
\"N]?\" { send \"y\r\"; exp_continue }
timeout { exit 1 }
}
expect eof
"
}
alias z=sshFuncB
Note the use of -c flag in expect which you can refer from here of you have any doubts.
If we use double quotes for the expect code with -c flag, it will allow the bash substitutions. If you use single quotes for the same, then bash substitutions won't work. (You have used #1 inside expect, which is why I used double quotes) Since I have used double quotes for the whole expect code, we have to escape the each double quotes with backslash inside the expect statement like as follows,
expect {
# Escaping the double quote with backslash
\"password: \" {some_action_here}
}
One more update. Since this is about connecting to the router and do some of your manual operations, then it is better to have interact at the end.