Preserving quotes in bash function parameters

Question

What I\'d like to do is take, as an input to a function, a line that may include quotes (single or double) and echo that line exactly as it was provided to the function. For

Answer 1

Although @Peter Westlake's answer is correct, and there are no quotes to preserve one can try to deduce if the quotes where required and thus passed in originally. Personally I used this requote function when I needed a proof in my logs that a command ran with the correct quoting:

function requote() {
    local res=""
    for x in "${@}" ; do
        # try to figure out if quoting was required for the $x:
        grep -q "[[:space:]]" <<< "$x" && res="${res} '${x}'" || res="${res} ${x}"
    done
    # remove first space and print:
    sed -e 's/^ //' <<< "${res}"
}

And here is how I use it:

CMD=$(requote "${@}")
# ...
echo "${CMD}"