Expect script for rsync with quotation marks

Question

I want to rsync a folder to another machine. sshpass is not an option and certificates don't either. So I'm stuck with expect.

So far, I have this bash script (minimized).

read -p "Enter remote IP: " IP
read -p "Enter remote user: " USER
read -s -p "Enter remote password: " PASSWORD
expect <<EOF
    set timeout -1
    spawn rsync -e "ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null" \
        -aHv --exclude=".*/" --delete ../.. ${USER}@${IP}:~/destination
    expect "password: "
    send "${PASSWORD}\n"
    expect eof
EOF

Problem is that rsync doesn't respect the "--exclude" option. In the stdout, I see:

spawn rsync -e ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -aHv --exclude=".*/" --delete ../.. pi@10.0.1.2:~/OberonHAP

Somehow, the quotes around the -e option vanished, but exclude still has them.

So I escape the quotes

expect <<EOF
    set timeout -1
    spawn rsync -e \"ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null\" \
        -aHv --exclude=".*/" --delete ../.. ${USER}@${IP}:~/destination
    expect "password: "
    send "${PASSWORD}\n"
    expect eof
EOF

but now I get

Missing trailing-" in remote-shell command.

Note that the command itself works perfectly when typed directly into a Terminal.

I've also tried different things, like 'EOF' heredoc and passing in the variables via environment, but always get error messages of different sorts :-)

How do I have to escape the rsync command so that it works fine?

Answer 1

Tcl's syntax (and hence Expect's syntax) is not the same as that of the shell. In particular, the quoting rules are different; you don't need to put double-quoting in the middle of a word as Tcl doesn't expand glob characters for you (you'd need to call glob explicitly if you wanted that). This means that your spawn command is actually best written as:

spawn rsync -e "ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null" \
    -aHv --exclude=.*/ --delete ../.. ${USER}@${IP}:~/destination
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