examples/external_rules/ruld

   1 #! /usr/bin/env lua
   2
   3 local p = require("posix")
   4 local port = 54321
   5
   6 local short = "hp:"
   7 local long = {
   8     {"help", "none", 'h'},
   9     {"port", "required", 'p'},
  10 }
  11
  12 local rules = {}
  13
  14 for opt, optarg, optind, longind in p.getopt(arg, short, long) do
  15     if opt == '?' then
  16         print("Unrecognized option")
  17         os.exit(1)
  18     elseif opt == 'h' then
  19         print("Usage: ruld [-h|-p PORT]")
  20         os.exit(0)
  21     elseif opt == 'p' then
  22         port = optarg
  23     end
  24 end
  25
  26 function eval(exp, env)
  27     local f
  28     local value = "return " .. exp
  29     if env then
  30         f = load(value, nil, nil, env)
  31     else
  32         f = load(value)
  33     end
  34     return f and f()
  35 end
  36
  37 function test(env)
  38     local rsp = ""
  39     for index = #rules, 1, -1 do
  40         local entry = rules[index]
  41         if eval(entry[1], env) then
  42             local delay, duration
  43             if entry[3] then
  44                 delay = entry[3].delay
  45                 duration = entry[3].duration
  46                 if delay and delay > 0 then
  47                     entry[3].delay = delay - 1
  48                 end
  49                 if ((not delay) or delay == 0) and duration and duration > 0 then
  50                     entry[3].duration = duration - 1
  51                 end
  52             end
  53             if (((not delay) or delay == 0) and ((not duration) or duration > 0)) then
  54                 if #rsp > 0 then
  55                     rsp = rsp .. " " .. entry[2]
  56                 else
  57                     rsp = entry[2]
  58                 end
  59             end
  60             if duration and duration <= 1 then
  61                 table.remove(rules, index)
  62             end
  63         end
  64     end
  65     return rsp
  66 end
  67
  68 local fd = p.socket(p.AF_INET, p.SOCK_STREAM, 0)
  69 p.setsockopt(fd, p.SOL_SOCKET, p.SO_REUSEADDR, 1)
  70 p.bind(fd, {family=p.AF_INET, addr="127.0.0.1", port=port})
  71 p.listen(fd, p.SOMAXCONN)
  72 local running = true
  73
  74 while running do
  75     ret_fd = p.accept(fd)
  76     if ret_fd then
  77         local msg = p.recv(ret_fd, p.BUFSIZ)
  78         if msg then
  79             local cmd, data = nil
  80             sep = msg:find(" ")
  81             if sep then
  82                 cmd = msg:sub(1, sep - 1)
  83                 data = msg:sub(sep + 1)
  84             else
  85                 cmd = msg
  86             end
  87             if cmd == "test" then
  88                 local env = eval(data)
  89                 if env then
  90                     rsp = test(env)
  91                     p.send(ret_fd, rsp)
  92                 end
  93             elseif cmd == "add" then
  94                 local value = eval(data)
  95                 if value then
  96                     table.insert(rules, value)
  97                 end
  98             elseif cmd == "remove" then
  99                 if data == "tail" then
 100                     table.remove(rules, #rules)
 101                 elseif data == "head" then
 102                     table.remove(rules, 1)
 103                 else
 104                     for index = #rules, 1, -1 do
 105                         if rules[index][1]:find(data) then
 106                             table.remove(rules, index)
 107                         end
 108                     end
 109                 end
 110             elseif cmd == "quit" then
 111                 running = false
 112             elseif cmd == "list" then
 113                 local rsp = ""
 114                 for index, entry in pairs(rules) do
 115                     rsp = rsp .. string.format("%s => %s", entry[1], entry[2])
 116                     if entry[3] then
 117                         if entry[3].delay then
 118                             rsp = rsp .. string.format(" @%i", entry[3].delay)
 119                         end
 120                         if entry[3].duration then
 121                             rsp = rsp .. string.format(" +%i", entry[3].duration)
 122                         end
 123                     end
 124                     if index < #rules then
 125                         rsp = rsp .. "\n"
 126                     end
 127                 end
 128                 p.send(ret_fd, rsp)
 129             end
 130         end
 131         p.close(ret_fd)
 132     end
 133 end
 134
 135 p.close(fd)