modules/luci-base/luasrc/http/protocol/date.lua

   1 -- Copyright 2008 Freifunk Leipzig / Jo-Philipp Wich <jow@openwrt.org>
   2 -- Licensed to the public under the Apache License 2.0.
   3
   4 -- This class contains functions to parse, compare and format http dates.
   5 module("luci.http.protocol.date", package.seeall)
   6
   7 require("luci.sys.zoneinfo")
   8
   9
  10 MONTHS = {
  11         "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug",
  12         "Sep", "Oct", "Nov", "Dec"
  13 }
  14
  15 function tz_offset(tz)
  16
  17         if type(tz) == "string" then
  18
  19                 -- check for a numeric identifier
  20                 local s, v = tz:match("([%+%-])([0-9]+)")
  21                 if s == '+' then s = 1 else s = -1 end
  22                 if v then v = tonumber(v) end
  23
  24                 if s and v then
  25                         return s * 60 * ( math.floor( v / 100 ) * 60 + ( v % 100 ) )
  26
  27                 -- lookup symbolic tz
  28                 elseif luci.sys.zoneinfo.OFFSET[tz:lower()] then
  29                         return luci.sys.zoneinfo.OFFSET[tz:lower()]
  30                 end
  31
  32         end
  33
  34         -- bad luck
  35         return 0
  36 end
  37
  38 function to_unix(date)
  39
  40         local wd, day, mon, yr, hr, min, sec, tz = date:match(
  41                 "([A-Z][a-z][a-z]), ([0-9]+) " ..
  42                 "([A-Z][a-z][a-z]) ([0-9]+) " ..
  43                 "([0-9]+):([0-9]+):([0-9]+) " ..
  44                 "([A-Z0-9%+%-]+)"
  45         )
  46
  47         if day and mon and yr and hr and min and sec then
  48                 -- find month
  49                 local month = 1
  50                 for i = 1, 12 do
  51                         if MONTHS[i] == mon then
  52                                 month = i
  53                                 break
  54                         end
  55                 end
  56
  57                 -- convert to epoch time
  58                 return tz_offset(tz) + os.time( {
  59                         year  = yr,
  60                         month = month,
  61                         day   = day,
  62                         hour  = hr,
  63                         min   = min,
  64                         sec   = sec
  65                 } )
  66         end
  67
  68         return 0
  69 end
  70
  71 function to_http(time)
  72         return os.date( "%a, %d %b %Y %H:%M:%S GMT", time )
  73 end
  74
  75 function compare(d1, d2)
  76
  77         if d1:match("[^0-9]") then d1 = to_unix(d1) end
  78         if d2:match("[^0-9]") then d2 = to_unix(d2) end
  79
  80         if d1 == d2 then
  81                 return 0
  82         elseif d1 < d2 then
  83                 return -1
  84         else
  85                 return 1
  86         end
  87 end