add maximum url parameter; document special list in readme

abrechenbarkeit.lua

@@ -584,7 +584,7 @@ local function r_users(show_special, filter_negative)
             local is_spu = user.name:sub(1, 1) == "@"
             local filter_out = query.prefix ~= nil and user.name:sub(1, 1):lower() ~= query.prefix
             if (filter_negative ~= nil and user.balance < filter_negative)
-            	or (filter_negative == nil and is_spu == show_special and not filter_out) then
+            	or (filter_negative == nil and is_spu == show_special and (not filter_out)) then
                 print(format([[<li>
                     <a href="/{username_url}">
                         <span class="name">{!username}</span>
@@ -599,9 +599,10 @@ local function r_users(show_special, filter_negative)
         end
         local inactive_cutoff = os.time() - (tonumber(config.inactive_cutoff) or (30 * 24 * 60 * 60))
         for _, user in ipairs(get_active_users()) do
-            if user.time > inactive_cutoff then show_user(user) end
+            if filter_negative or user.time > inactive_cutoff then show_user(user) end
         end
         print("</ul>")
+        if filter_negative ~= nil then return end
         print(format([[<details><summary>{+users.inactive_list}</summary><ul class="userlist">]]))
         for _, user in ipairs(users) do
             if user.time <= inactive_cutoff then show_user(user) end
@@ -802,8 +803,7 @@ if path == "/" then
     elseif query.users and query.export then
 		return r_export_balances()
     else
-        return r_users(false, query.negative)
-        -- tonumber(query.negative or 0) or nil)
+        return r_users(false, query.negative and (query.maximum or 0))
     end
 else
     local username = extract_username()

readme.md

@@ -23,3 +23,8 @@ useful for development or proxyless deployments.
 curl 'http://strichliste.example.org/api/user?deleted=false' | jq -r '.users.[] | [ 0, "@Potential", .name, .balance, "", "", "" ] | join(",")' > log
 curl 'http://strichliste.example.org/api/article' | jq -r '.articles.[] | [ .barcode, .amount, "@Drinks", .name ] | join(",")' > products
 ```
+
+## Non-linked User lists
+
+- list of Users with negative balance: `http://abrechenbarkeit.example.org/?negative`
+- list of Users with balance lower than <amount>: `http://abrechenbarkeit.example.org/?negative&maximum=<amount>`