How to use ssh -t command which includes grep with quotes

Question

I am trying to grep the third octet in IP address to an tap device on remote machine.

ssh -t user@host "/sbin/ifconfig tap0 | grep "inet" | /usr/bin/awk -F'[: ]+' '{ print $4 }' | awk -F'[.]' '{print $3}'"

I am resulting this:

inet addr:10.22.66.77  Bcast:10.22.66.255  Mask:255.255.255.0

When i run the command on the remote machine it shows 66

How to make it working with ssh -t?

Why do you use `-t`? Why `/usr/bin` and `/sbin`? https://stackoverflow.com/questions/4412238/what-is-the-cleanest-way-to-ssh-and-run-multiple-commands-in-bash — KamilCuk, Jul 13 '21 at 08:55
You could use heredoc syntax with SSH: https://unix.stackexchange.com/questions/187960/is-it-possible-to-send-a-heredoc-over-ssh-to-a-remote-host-from-inside-a-script. — Marko E, Jul 13 '21 at 09:19
you have unmatched quotes. Don't you see that from the syntax highlighting? — phuclv, Jul 13 '21 at 17:13

score 2 · Accepted Answer · answered Jul 13 '21 at 17:04

Sometimes using perl is simpler:

ssh -t user@host "/sbin/ifconfig tap0" | perl -n -e 'if (/inet\saddr:\d+\.\d+\.(\d+)/) { print "$1\n"}'

it runs regular expression pattern on the local machine match on the third octet following addr: and this is then printed via $1

The pattern match is run on the local machine to avoid problems with escaping " (In your example code the " in the grep inet seems to terminate the ssh...)

How to use ssh -t command which includes grep with quotes

1 Answers1