contrib/statusd/statusd_mpd.lua

   1 -- Authors: <delirium@hackish.org>
   2 -- License: Unknown
   3 -- Last Changed: Unknown
   4 --
   5 -- statusd for MPD (Music Player Daemon)
   6 -- bugs/requests/comments: delirium@hackish.org
   7
   8 -- requires that netcat is available in the path
   9
  10 local defaults={
  11     -- 500 or less makes seconds increment relatively smoothly while playing
  12     update_interval=500,
  13
  14     -- mpd server info (localhost:6600 are mpd defaults)
  15     address="localhost",
  16     port=6600,
  17
  18     -- mpd password (if any)
  19     password=nil,
  20
  21     -- display template
  22     -- ---
  23     -- can use the following:
  24     --   track metadata: %artist, %title, %num, %album, %year, %len
  25     --   current track position: %pos
  26     --   escape for the percent character: %%
  27
  28     -- a default template
  29     template = "%artist - %num - %title (%pos / %len)"
  30 }
  31
  32 local settings=table.join(statusd.get_config("mpd"), defaults)
  33
  34 local success
  35 local last_success
  36
  37 local function saferead(file)
  38         local data, err, errno
  39         repeat
  40                 data, err, errno = file:read()
  41         until errno ~= 4 -- EINTR
  42         return data, err, errno
  43 end
  44
  45 local function get_mpd_status()
  46
  47     -- The first version of cmd_string is the original, however, some versions
  48     -- of MPD close the socket too quickly if close is included. If you see the
  49     -- message: error querying mpd status
  50     -- then try the second version.
  51     local cmd_string = "status\ncurrentsong\nclose\n"
  52 --    local cmd_string = "status\ncurrentsong\n"
  53
  54     if settings.password ~= nil then
  55         cmd_string = "password " .. settings.password .. "\n" .. cmd_string
  56     end
  57     cmd_string = string.format('echo -n "%s" | netcat %s %d',
  58                                cmd_string, settings.address, settings.port)
  59
  60     last_success = success
  61     success = false
  62
  63     local mpd = io.popen(cmd_string, "r")
  64
  65     -- welcome msg
  66     local data = saferead(mpd)
  67     if data == nil or string.sub(data,1,6) ~= "OK MPD" then
  68         mpd:close()
  69         return "mpd not running"
  70     end
  71
  72     -- 'password' response (if necessary)
  73     if settings.password ~= nil then
  74         repeat
  75             data = saferead(mpd)
  76         until data == nil or string.sub(data,1,2) == "OK" or string.sub(data,1,3) == "ACK"
  77         if data == nil or string.sub(data,1,2) ~= "OK" then
  78             mpd:close()
  79             return "bad mpd password"
  80         end
  81     end
  82
  83     local info = {}
  84
  85     -- 'status' response
  86     repeat
  87         data = saferead(mpd)
  88         if data == nil then break end
  89
  90         local _,_,attrib,val = string.find(data, "(.-): (.*)")
  91         if attrib == "time" then
  92             _,_,info.pos,info.len = string.find(val, "(%d+):(%d+)")
  93
  94             -- Around Lua 5.1, math.mod() was renamed math.fmod().
  95             if type(math.mod) == "function" then
  96                info.pos = string.format("%d:%02d", math.floor(info.pos / 60), math.mod(info.pos, 60))
  97                info.len = string.format("%d:%02d", math.floor(info.len / 60), math.mod(info.len, 60))
  98             else
  99                info.pos = string.format("%d:%02d", math.floor(info.pos / 60), math.fmod(info.pos, 60))
 100                info.len = string.format("%d:%02d", math.floor(info.len / 60), math.fmod(info.len, 60))
 101             end
 102         elseif attrib == "state" then
 103             info.state = val
 104         end
 105     until string.sub(data,1,2) == "OK" or string.sub(data,1,3) == "ACK"
 106     if data == nil or string.sub(data,1,2) ~= "OK" then
 107         mpd:close()
 108         return "error querying mpd status"
 109     end
 110
 111     -- 'currentsong' response
 112     repeat
 113         data = saferead(mpd)
 114         if data == nil then break end
 115
 116         local _,_,attrib,val = string.find(data, "(.-): (.*)")
 117         if     attrib == "Artist" then info.artist = val
 118         elseif attrib == "Title"  then info.title  = val
 119         elseif attrib == "Album"  then info.album  = val
 120         elseif attrib == "Track"  then info.num    = val
 121         elseif attrib == "Date"   then info.year   = val
 122         end
 123     until string.sub(data,1,2) == "OK" or string.sub(data,1,3) == "ACK"
 124     if data == nil or string.sub(data,1,2) ~= "OK" then
 125         mpd:close()
 126         return "error querying current song"
 127     end
 128
 129     mpd:close()
 130
 131     success = true
 132
 133     -- done querying; now build the string
 134     if info.state == "play" then
 135         local mpd_st = settings.template
 136         -- fill in %values
 137         mpd_st = string.gsub(mpd_st, "%%([%w%_]+)", function (x) return(info[x]  or "") end)
 138         mpd_st = string.gsub(mpd_st, "%%%%", "%%")
 139         return mpd_st
 140     elseif info.state == "pause" then
 141         return "Paused"
 142     else
 143         return "No song playing"
 144     end
 145 end
 146
 147
 148 local mpd_timer
 149
 150 local function update_mpd()
 151     -- update unless there's an error that's not yet twice in a row, to allow
 152     -- for transient errors due to load spikes
 153     local mpd_st = get_mpd_status()
 154     if success or not last_success then
 155         statusd.inform("mpd", mpd_st)
 156     end
 157     mpd_timer:set(settings.update_interval, update_mpd)
 158 end
 159
 160 -- Init
 161 mpd_timer=statusd.create_timer()
 162 update_mpd()
 163