(This answer might seem needlessly complicated, but it’s easily extensible and robust regarding whitespace and special characters, as far as I know.)
You can feed data right through the standard input of the ssh command and read that from the remote location.
In the following example,
ssh a null-terminated line giving the name and value of the variable.shh command itself, we loop through these lines to initialise the required variables.# Initialize examples of variables.
# The first one even contains whitespace and a newline.
readonly FOO=$'apjlljs ailsi \n ajlls\t éjij'
readonly BAR=ygnàgyààynygbjrbjrb
# Make a list of what you want to pass through SSH.
# (The “unset” is just in case someone exported
# an associative array with this name.)
unset -v VAR_NAMES
readonly VAR_NAMES=(
FOO
BAR
)
for name in "${VAR_NAMES[@]}"
do
printf '%s %s\0' "$name" "${!name}"
done | ssh [email protected] '
while read -rd '"''"' name value
do
export "$name"="$value"
done
# Check
printf "FOO = [%q]; BAR = [%q]\n" "$FOO" "$BAR"
'
Output:
FOO = [$'apjlljs ailsi \n ajlls\t éjij']; BAR = [ygnàgyààynygbjrbjrb]
If you don’t need to export those, you should be able to use declare instead of export.
A really simplified version (if you don’t need the extensibility, have a single variable to process, etc.) would look like:
$ ssh [email protected] 'read foo' <<< "$foo"