contrib/statusd/statusd_fortune.lua

   1 -- Authors: Hendrik Iben <hiben@tzi.de>
   2 -- License: GPL, version 2
   3 -- Last Changed: 2006-03-23
   4 --
   5 -- statusd_fortune.lua v20060323
   6 --
   7 -- Displays a fortune (in a sane way for one line).
   8 -- My first attempt at writing in lua and for ion.
   9 --
  10 -- Written by Hendrik Iben < hiben at tzi dot de >
  11 --
  12 -- How to use :
  13 -- fortune provides a monitor for statusd.
  14 -- This monitor is feed with a fortune obtained from the famous fortune-
  15 -- program. But as fortunes can span several lines and the ion-statusbar
  16 -- only provides one line there is some conversion done.
  17 --
  18 -- As a user you can influence the way this conversion is done by specifying
  19 -- with what string empty space and newlines are to be replaced. Or just
  20 -- leave the defaults.
  21 --
  22 -- For a start you can simple add '%fortune' to your statusbar-template.
  23 --
  24 -- Requirements:
  25 -- ion3 (tested with 20060305 gentoo ebuild)
  26 -- lua (tested with 5.0.2)
  27 -- fortune (any version will do) or anything that returns text :-)
  28 --
  29 -- Options :
  30 -- The settings you can specify (and their defaults) are :
  31 -- interval     : minimum time between fortune updates (60 seconds)
  32 -- minwait      : additional time to always wait for a fortune (6 seconds)
  33 -- cpers        : number of characters to increase waiting by one second (20)
  34 -- command      : command to obtain a fortune (fortune -s)
  35 -- prefix       : head of every fortune
  36 -- postfix      : tail of every fortune
  37 -- spacereplace : string that replaces empty space of more than 3 characters
  38 --                (' - ')
  39 -- newline      : string that replaces newlines (' > ')
  40 -- newlinetrick : try to be smart when killing newlines (true)
  41 --
  42 -- Setting 'interval' and 'minwait' together might seem useless but when
  43 -- calculating  the waiting time the maximum of 'minwait' and the time
  44 -- resulting from 'cpers' is added to 'interval'. The defaults for 'minwait'
  45 -- and 'cpers' are taken from fortunes source.
  46 --
  47 -- The default command triggers a short fortune (see: man fortune) as long
  48 -- fortunes tend to fill more than one line in the status-bar. You may wish
  49 -- to enable offending fortunes but I personally don't like them that much...
  50 -- In my opinion the statusbar should offer things like scrolling text but
  51 -- eventually I will implement this in a later release of this monitor...
  52 --
  53 -- Enabling 'newlinetrick' basicly makes this program look at the ending and
  54 -- beginning of the two lines and check if they are *meant* to be separated.
  55 -- Currently this merges lines that end and begin with lower-case-letters and
  56 -- silently removes newlines in front of 'cite-signs' (e.g.
  57 -- "...blah\n-- Hendrik" becomes "...blah -- Hendrik").
  58 --
  59 -- Example configuration :
  60 -- cfg_statusbar (rotate_statusbar that is)
  61 --   ...
  62 --   ...
  63 --   rotate_statusbar.configurations = {
  64 --     ...
  65 --     ...
  66 --      fortune = {
  67 --        prefix = "Fortune : ",
  68 --        interval = 30*1000,
  69 --     },
  70 --     ...
  71 --     ...
  72 --
  73 --   rotate_statusbar.settings = {
  74 --    ...
  75 --    ...
  76 --    all_statusbars = {
  77 --      "[ %date || %xmmsip_user ]%filler%systray",
  78 --      "[ %fortune ]%filler%systray",
  79 --      ...
  80 --      ...
  81 --
  82 -- This setup makes the basic fortune update all 30 seconds and prepends
  83 -- every fortune with 'Fortune : '. Also using rotate_statusbar I decided
  84 -- to give fortunes the full bar turning of the date-monitor so I don't
  85 -- perceive how much time I spend on watching fortunes instead of doing
  86 -- more creative things... :-)
  87 --
  88 -- Happy fortunes for you!
  89 --
  90 -- Feel free to contact me if you discover bugs or want to comment on this.
  91 --  -- Hendrik
  92 --
  93 -- You are free to distribute this software under the terms of the GNU
  94 -- General Public License Version 2.
  95
  96 if not statusd_fortune then
  97   statusd_fortune={
  98     interval=60*1000,
  99     minwait=6*1000,
 100     cpers=20,
 101     command="fortune -s",
 102     prefix="",
 103     postfix="",
 104     spacereplace=" - ",
 105     newline=" > ",
 106     newlinetrick=true,
 107   }
 108 end
 109
 110 local settings = table.join (statusd.get_config("fortune"), statusd_fortune)
 111
 112 -- do things to strings...
 113 -- did I mention I write Haskell normally ? :-)
 114 local function flatspace(s)
 115   return
 116     string.gsub( -- 1. remaining controls
 117       string.gsub( -- 2. newlines not covered by newlinetrick
 118         string.gsub( -- 3. spaces
 119           string.gsub( -- 4. remove trailing control + space
 120             string.gsub(s, "^[%c%s]+", "") -- 5. remove leading control + space
 121             , "[%c%s]+$"
 122             , ""
 123           ) -- > 4.
 124           , "%s%s%s%s+"
 125           , settings.spacereplace
 126         ) -- > 3.
 127         , "\n+"
 128         , settings.newline
 129       ) -- > 2.
 130       , "%c"
 131       , ""
 132     ) -- > 1.
 133 end
 134
 135 -- our timer
 136 local fortune_timer
 137
 138 -- on error we get the message, but a bit to late...
 139 local last_error = "error pending..."
 140
 141 -- receives data from settings.command output
 142 local function receive_fortune_status(partial_data)
 143   local fortunestring = ""
 144
 145   while partial_data
 146     do
 147       fortunestring = fortunestring .. partial_data
 148       partial_data = coroutine.yield()
 149     end
 150
 151   if (not fortunestring) or (fortunestring == "")
 152     then
 153       -- we get here if e.g. the command was not found...
 154       fortunestring = "could not obtain a fortune! ("..last_error..")"
 155   end
 156
 157   -- perform newline-merging
 158   if settings.newlinetrick
 159     then
 160       -- trick 1 : wrapped sentences
 161       fortunestring = string.gsub(fortunestring, "(%l)\n(%l)", "%1 %2")
 162       -- trick 2 : 'cite-signs'
 163       fortunestring = string.gsub(fortunestring, "([^\n]*)[%c%s]*(--.*)", "%1 %2")
 164   end
 165
 166   -- flatspace is such a silly name...
 167   local f = flatspace(fortunestring)
 168
 169   -- calculate time to wait
 170   local waittime =
 171     settings.interval
 172     + math.max(
 173        settings.minwait -- minimun
 174       ,1000 * (string.len(f) / settings.cpers) -- maybe more
 175     )
 176
 177   -- feed the monitor
 178   statusd.inform("fortune", settings.prefix..f..settings.postfix)
 179
 180   -- update callback
 181   fortune_timer:set(waittime, update_fortune)
 182 end
 183
 184 local function flush_stderr(partial_data)
 185   local r = ""
 186
 187   while partial_data
 188     do
 189       r = r .. partial_data
 190       partial_data = coroutine.yield()
 191     end
 192   -- update last error to give the user a hint...
 193   last_error = r
 194 end
 195
 196 --- monitor-update
 197 function update_fortune()
 198   statusd.popen_bgread(
 199       settings.command
 200     , coroutine.wrap(receive_fortune_status)
 201     , coroutine.wrap(flush_stderr)
 202     )
 203 end
 204
 205 -- initialize our timer
 206 fortune_timer = statusd.create_timer()
 207 -- begin
 208 update_fortune()