Lua Cant capture all output from io.popen

[dearikomaru]

Lua:
function func.execute(command)
    local f = io.popen(command .. ' 2>&1 && echo " $?"')
    local output = assert(f:read "*a")
    local tempOutput = output
    local begin, _, code = output:find " (%d+)\n$"
    if begin == nil or begin == '' then
        output = table.concat(func.strSplit('\n', tempOutput), "|.|")
    else
        output, code = output:sub(1, begin - 1), tonumber(code)
    end
    return code == 0 and true or false, code, output
end

From the code above, if I run the command "cd somewhere && cat file". Condition that occurs if the first command fails (directory not found) then the resulting output is an empty string. And if all fails, then the output that is caught is only the last command (if there are 3 commands then only the 3rd output is caught). I want if the message failed that appears caught all. For example from this command "cd somewhere && cat file" and then the output is "bash: cd: somewhere: No such file or directory\n" like that. Please help me. thank you.