lua-basic/tokenize_args.lua

function tokenize_args(raw)
    -- NOTE: string.gmatch is does not use regex, but a smaller pattern matcher!
    -- A complete regex parser would be larger than lua itself. See
    -- [Programming in Lua 20.2](https://www.lua.org/pil/20.2.html).
    --
    -- Notable differences:
    -- '-' is ungreedy wildcard
    -- '*?' does not work
    -- '|' is not or
    --
    -- This means we're better of implementing the lexer with an algorithm.
    local t = {}
    local current = ""
    local in_str = false
    local str_seek
    for c in string.gmatch(raw, ".") do -- iterate through all chars
        if c == ' ' and not in_str then
            if string.len(current) > 0 then
                table.insert(t, current)
                current = ""
            end
        elseif c == '"' and not in_str then
            in_str = true
            str_seek = '"'
        elseif c == "'" and not in_str then
            in_str = true
            str_seek = "'"
        elseif c == str_seek and in_str then
            in_str = false
            table.insert(t, current)
            current = ""
        else
            current = current .. c
        end
    end
    if string.len(current) > 0 then
        table.insert(t, current)
    end
    return t
end

--- dumps a variable into a string, so it can be printed. This is meant for
--- debug prints
--- @param any t any variable
--- @return string t_dumped t dumped to string
function dump(t)
    if type(t) == 'table' then
        local s = '{ '
        for k, v in pairs(t) do
            if type(k) ~= 'number' then k = '"' .. k .. '"' end
            if k ~= 1 then
                s = s .. ', '
            end
            s = s .. '[' .. k .. '] = \'' .. dump(v) .. '\''
        end
        return s .. ' }'
    else
        return tostring(t)
    end
end

function main()
    local mockargs =
    [[--name "tls_service_rs" --base-dir ${PWD%/*/*} --log-level "TRACE" -j '{ "MODE": "server", "CERT": "data/server.crt", "KEY": "data/server.key", "CHAIN": "data/root.crt", "ADDR": "127.0.0.1:9999", "HOSTNAME": "localhost" }']]
    print(mockargs)
    local split = tokenize_args(mockargs)
    print(dump(split))
end

if pcall(getfenv, 4) then
    print("Library")
else
    main()
end