Issue
I have a situation where in my BASH script, I need to encode an environment variable to base64 and write it to a json file, which is then picked up by docker.
I have the below code for this:
USER64=$(echo $USER | base64)
echo '{"auths": {"auth": "'"$USER64"'}}' > ~/.docker/config.json
This works, but the problem is the encoded value of $USER contains a \n so the echo writes it into the config file as 2 lines. How can I escape all the \n while encoding the $USER and write it to the config file?
Solution
You can use the substitution operator in shell parameter expansion.
echo '{"auths": {"auth": "'"${USER64/$'\n'/\\\n}"'}}' > ~/.docker/config.json
But you can also use an option to base64 to prevent it from putting newlines into the encoding in the first place.
USER64=$(echo $USER | base64 --wrap=0)
Answered By - Barmar Answer Checked By - Dawn Plyler (WPSolving Volunteer)