contrib/statusbar/statusbar_external.lua

   1 -- Authors: Antti Vähäkotamäki
   2 -- License: LGPL, version 2.1 or later
   3 -- Last Changed: 2005
   4 --
   5 -- statusbar_external.lua
   6 --
   7
   8 if not statusbar_external then
   9   statusbar_external = {
  10
  11     -- a simple example which shows utc time and date
  12     -- in %udate every second with 'date -u'
  13     {
  14         template_key = 'dateb',
  15         external_program = 'date',
  16         execute_delay = 1 * 1000,
  17     },
  18
  19     {
  20         template_key = 'udate',
  21         external_program = 'date -u',
  22         execute_delay = 5 * 1000,
  23     },
  24
  25     -- a more complicated example showing the usage
  26     -- percentage of hda1 every 30 seconds in %hda1u
  27     -- with df, grep and sed.
  28     {
  29         template_key = 'hda1u',
  30         external_program = 'df|grep hda1|sed "s/.*\\(..%\\).*/\\1/"',
  31         execute_delay = 30 * 1000,
  32         meter_length = 4,
  33         hint_regexp = {
  34             important = '9[456].',
  35             critical = {
  36                 '9[789].',
  37                 '1...',
  38             },
  39         },
  40    },
  41
  42   }
  43 end
  44
  45 --
  46 -- -- What is this?
  47 --
  48 -- This is a simple "general" statusbar lua script which
  49 -- lets you show output of external programs in ion
  50 -- statusbar. This is convenient if you are not familiar
  51 -- with lua but can handle yourself with some other
  52 -- language enough to output what you would want the
  53 -- statusbar to show.
  54 --
  55 --
  56 -- -- How to use it?
  57 --
  58 -- Short version:
  59 --
  60 -- 1 ) modify settings variable
  61 -- 2 ) update template to include specified keys
  62 -- 3 ) dopath( "statusbar_external" ) in cfg_user.lua
  63 --
  64 --
  65 -- Longer version:
  66 --
  67 -- There is an example settings-variable which can be
  68 -- modified to specify your own programs. The needed
  69 -- parameters are the following :
  70 --
  71 -- * template_key
  72 --  An unique name for the meter. You must add this
  73 --  name with preceding % (for example %meter_name)
  74 --  into your statusbar template which is usually set
  75 --  in cfg_statusbar.lua.
  76 --
  77 -- * external_program
  78 --  The program to execute. The last line of each
  79 --  flushed output this program writes to stdout is
  80 --  inserted as the content of the meter.
  81 --
  82 -- * execute_delay
  83 --  The delay to wait before running the program again
  84 --  once it stops sending data. Some programs just
  85 --  send the data and exit while others continue
  86 --  sending data periodically. This value can be used
  87 --  to control the update rate for the first type of
  88 --  programs.
  89 --
  90 -- * meter_length (optional)
  91 --  The space reserved for this meter in characters.
  92 --  If the value is not specified or is less than 1
  93 --  then the space is determined by the length of the
  94 --  data being shown but some people do not want their
  95 --  statusbar width to change randomly.
  96 --
  97 -- * hint_regexp (optional)
  98 --  These regular expressions (in Lua syntax) are
  99 --  matched with the data and in case of a match the
 100 --  named hint is set to the meter. The value can be
 101 --  either a string containing the regexp or a table
 102 --  containing several possible regexps (Lua regexp
 103 --  doesn't have an 'or'). By default the themes define
 104 --  a color for 'important' and 'critical' hints.
 105 --
 106 -- After this script is loaded it starts executing all
 107 -- the provided programs and updates the statusbar every
 108 -- time one of them prints (and flushes) something.
 109 --
 110 -- Also this is not a normal statusd script so it
 111 -- doesn't get loaded by template name automatically
 112 -- when ion starts. You must add
 113 --
 114 --   dopath( "statusbar_external" )
 115 --
 116 -- to some script that is being loaded in Ion. For
 117 -- example ~/.ion3/cfg_user.lua is a good place. Note
 118 -- that cfg_statusbar.lua is not loaded inside the
 119 -- Ion process but in a separate process and thus this
 120 -- script can not be loaded from that file!
 121 --
 122 --
 123
 124 ---------------------------------------------------------
 125
 126 local timers = {}
 127 local callbacks = {}
 128
 129 -- Just print out stderr for now.
 130 local function flush_stderr(partial_data)
 131     local result = ""
 132     while partial_data do
 133         result = result .. partial_data
 134         -- Yield until we get more input.  popen_bgread will call resume on us.
 135         partial_data = coroutine.yield()
 136     end
 137     print(result, "\n")
 138 end
 139
 140 -- Execute a program.  This will continuously retrieve output from the program.
 141 function start_execute(key)
 142    -- Read output from the program and (if data) then update the statusbar
 143    local handle_output_changes = coroutine.create(
 144        function(input_data)
 145           local key = input_data
 146           local data = ""
 147           local partial_data = ""
 148           -- Keep reading data until we have it all
 149           while partial_data do
 150              data = data .. partial_data
 151              -- Yield until we get more input.
 152              -- popen_bgread will call resume on us.
 153              partial_data = coroutine.yield()
 154           end
 155
 156           -- If no updates, then just schedule another run
 157           if not data or data == "" then
 158              return timers[key]:set(statusbar_external[key].execute_delay,
 159                                     callbacks[key])
 160           end
 161
 162           -- remove all but the last line
 163           data = string.gsub( data, "\n$", "" )
 164           data = string.gsub( data, ".*\n", "" );
 165
 166           local sets = statusbar_external[key]
 167           local t_key = sets.template_key
 168           local t_length = sets.meter_length
 169           local h_regexp = sets.hint_regexp
 170
 171           if not tlength or t_length < 1 then
 172              t_length = string.len( data )
 173           end
 174
 175           mod_statusbar.inform( t_key, data )
 176           mod_statusbar.inform( t_key .. "_hint", '' )
 177           mod_statusbar.inform(t_key .. "_template", string.rep( ' ', t_length))
 178
 179           if not h_regexp then h_regexp = {} end
 180
 181           for hint, re in pairs( h_regexp ) do
 182              if ( type( re ) == 'string' ) then
 183                 re = { re }
 184              end
 185
 186              for _, r in ipairs( re ) do
 187                 if ( string.find( data, r ) ) then
 188                    mod_statusbar.inform(t_key .. "_hint", hint)
 189                 end
 190              end
 191           end
 192
 193           mod_statusbar.update()
 194
 195           return timers[key]:set(statusbar_external[key].execute_delay,
 196                                  callbacks[key])
 197        end
 198     )
 199
 200    -- We need to pass it the key before calling a background call.
 201    coroutine.resume(handle_output_changes, key)
 202    ioncore.popen_bgread(statusbar_external[key].external_program,
 203                         function(cor) coroutine.resume(handle_output_changes,
 204                                                        cor) end,
 205                         coroutine.wrap(flush_stderr))
 206 end
 207
 208
 209 -- Start all
 210 for key in pairs(statusbar_external) do
 211     timers[key] = ioncore.create_timer()
 212         callbacks[key] = loadstring("start_execute("..key..")")
 213     start_execute(key)
 214 end
 215
 216 --
 217 -- Copyright (c) Antti Vähäkotamäki 2005.
 218 --
 219 -- Ion is free software; you can redistribute it and/or modify it under
 220 -- the terms of the GNU Lesser General Public License as published by
 221 -- the Free Software Foundation; either version 2.1 of the License, or
 222 -- (at your option) any later version.
 223 --