Question

Im trying to do log into a file (in a remote server lets say /home/test/log.txt) what is stored in $var. Im trying with

ssh test@$192.168.1.35 "echo "var" >> /home/test/log.txt"

y also tried

 ssh test@$192.168.1.35 "echo "$var" >> log.txt"

but the both didnt work

any help?

Answer 1

You’re using double quotes, so the variable expansion will happen locally. You should use single quotes, so that the command gets sent unaltered.

In the same way as echo '$var' gives $var while echo "$var" displays the contents, this way the server sees $var instead of the contents of the local $var.

So:

ssh test@$192.168.1.35 'echo $var >> /home/test/log.txt'

will create a file on the remote computer, with the value of the remote $var in it.

If you do

ssh test@$192.168.1.35 'echo $var' >> /home/test/log.txt

you get a file on the local computer with the value of the remote $var in it.

If you do

ssh test@$192.168.1.35 "echo $var >> /home/test/log.txt"

it stores the value of your local $var in the file on the remote system.

(Also, if it only involves the remote system, you should probably use a shell script, or maybe cron if you want it to happen automatically.)