How can i unset a variable which has dot in it for example: s3.protocol
I tried to unset with the following command and i get the error
unset s3.protocol
bash: unset: `s3.protocol': not a valid identifier
env | grep -i protocol
amazon.s3.protocol=HTTPS
s3.protocol=HTTPS
elasticsearch.protocol=https
If your variable appears in env, you can replace the current shell with another shell that does not have the environment variable in it. Assuming you want to remove all three variables.
exec env -u amazon.s3.protocol -u s3.protocol -u elasticsearch.protocol "$SHELL"
The env -u removes the specified variables before launching another copy of the current shell. I used $SHELL here for illustration but you should replace it with the name or path to your actual shell (which for example can be bash or /usr/local/bin/bash-4), or you can use $0 if it makes sense. The exec ensures that the new shell replaces the current shell instead of being launched as a subshell.
To also forward all command line arguments of the current shell and all the variables local to the current shell, some extra arguments can be added.
exec env -u amazon.s3.protocol -u s3.protocol -u elasticsearch.protocol "$SHELL" "$@" --rcfile <(echo ". ~/.bashrc; $(declare -p| awk '($2 !~ "r")')")
Where "$@" forwards all the command line arguments to the new shell (assuming shift has not been used directly in the current shell), and the $(declare -p) extracts all the bash variables in the current shell. The output of declare -p is passed to awk to remove readonly variables, then passed to the new shell via the mechanism presented in this answer.