Simplify configuration

The host split turned to be a vast overengineering.

src/common.lua

 os = require "os"
-socket = require "socket"
 
 
 ------------------------------------------------------------------------------
 -- config and handling                                                      --
 ------------------------------------------------------------------------------
 
-function shortname()
-    --
-    -- Short hostname
-    --
-    local long = socket.dns.gethostname()
-    return string.gmatch(long, '[^.]+')()
-end
-
 function file_exists(name)
     --
     -- True if file *name* exists
     end
 end
 
-function init_host(session)
+function do_if_exists(filename)
     --
-    -- Do host-specific init, if exists
+    -- Do file from home, if exists
     --
-    local init = session.dirs.host .. "/init.lua"
-    if file_exists(init) then
-        dofile(init)
+    local file = os.getenv("IMAPFILTER_HOME") .. "/" .. filename
+    if file_exists(file) then
+        dofile(file)
         return
     end
 end
 
-function handle(session)
+function handle()
     --
-    -- Look for action handler in session dirs; do first one that exists
+    -- Handle action if it's valid
     --
+    local action = os.getenv("IMAPDOMO_ACTION")
     local valid = {
         newmail = true,
         rewind = true,
         cleanup = true,
         migrate = true
     }
-    if not valid[session.action] then
-        error("invalid action: " .. session.action)
+    if not valid[action] then
+        error("invalid action: " .. action)
         return nil
     end
-    init_host(session)
-    for k,v in ipairs({session.dirs.host, session.dirs.default}) do
-        attempt = v .. "/handlers/" .. session.action .. ".lua"
-        if file_exists(attempt) then
-            dofile(attempt)
-            return
-        end
-    end
+    do_if_exists("init.lua")
+    do_if_exists("handlers/" .. action .. ".lua")
 end
 
 

src/imapdomo.skel

             "-c DIR      change to DIR before doing anything"                 \
             "-d          turn on debugging mode"                              \
        --                                                                     \
-       "imapdomo will try to read .imapdomo/host/HOSTNAME/init.lua and"       \
-       ".imapdomo/host/HOSTNAME/handlers/ACTION.lua, where HOSTNAME is your"  \
-       "short hostname (eg. 'foo' in 'foo.example.com')."                     \
+       "imapdomo will try to read init.lua and handlers/ACTION.lua from its"  \
+       "configuration directory."                                             \
        ""                                                                     \
        "four valid actions are understood; since you must write handler for"  \
        "each action you want to use, the meanings below are purely a guide:"  \

src/main.lua.skel

 
 dofile "__IMAPDOMO_SHARE__/common.lua"
 
-handle({
-    action = os.getenv("IMAPDOMO_ACTION"),
-    dirs = {
-        host = os.getenv("IMAPFILTER_HOME") .. "/host/" .. shortname(),
-        defhost = os.getenv("IMAPFILTER_HOME") .. "/default",
-    }
-})
+handle()