{alsa,pulse}bar: fallback for mywibox variable; closes #384

[etc/awesome.git] / helpers.lua

diff --git a/helpers.lua b/helpers.lua
index af6443fb88a51f4c4c0083b82f66465241ea211b..fb71335f91a25a6a6b995648a91a8e45e2ef2649 100644 (file)
--- a/helpers.lua
+++ b/helpers.lua
@@ -1,18 +1,18 @@
-

 --[[
 --[[

-                                                  
-     Licensed under GNU General Public License v2 
-      * (c) 2013,      Luke Bonham                
-      * (c) 2010-2012, Peter Hofmann              
-                                                  
---]]

 
 

-local debug  = require("debug")
+     Licensed under GNU General Public License v2
+      * (c) 2013, Luca CPZ
+
+--]]

 
 

-local capi   = { timer = timer }
-local io     = { open = io.open,
-                 lines = io.lines }
-local rawget = rawget
+local spawn      = require("awful.spawn")
+local timer      = require("gears.timer")
+local debug      = require("debug")
+local io         = { lines = io.lines,
+                     open  = io.open }
+local pairs      = pairs
+local rawget     = rawget
+local table      = { sort  = table.sort }

 
 -- Lain helper functions for internal use
 -- lain.helpers
 
 -- Lain helper functions for internal use
 -- lain.helpers


@@ -33,25 +33,40 @@ end
 
 -- {{{ File operations
 
 
 -- {{{ File operations
 

--- see if the file exists
+-- see if the file exists and is readable

 function helpers.file_exists(file)
 function helpers.file_exists(file)

-  local f = io.open(file, "rb")
-  if f then f:close() end
+  local f = io.open(file)
+  if f then
+      local s = f:read()
+      f:close()
+      f = s
+  end

   return f ~= nil
 end
 
   return f ~= nil
 end
 

-
--- get all lines from a file, returns an empty 
+-- get all lines from a file, returns an empty

 -- list/table if the file does not exist
 function helpers.lines_from(file)
   if not helpers.file_exists(file) then return {} end
 -- list/table if the file does not exist
 function helpers.lines_from(file)
   if not helpers.file_exists(file) then return {} end

-  lines = {}
-  for line in io.lines(file) do 
+  local lines = {}
+  for line in io.lines(file) do

     lines[#lines + 1] = line
   end
   return lines
 end
 
     lines[#lines + 1] = line
   end
   return lines
 end
 

+-- match all lines from a file, returns an empty
+-- list/table if the file or match does not exist
+function helpers.lines_match(regexp, file)
+       local lines = {}
+       for index,line in pairs(helpers.lines_from(file)) do
+               if string.match(line, regexp) then
+                       lines[index] = line
+               end
+       end
+       return lines
+end
+

 -- get first line of a file, return nil if
 -- the file does not exist
 function helpers.first_line(file)
 -- get first line of a file, return nil if
 -- the file does not exist
 function helpers.first_line(file)


@@ -62,7 +77,7 @@ end
 -- returns nil otherwise
 function helpers.first_nonempty_line(file)
   for k,v in pairs(helpers.lines_from(file)) do
 -- returns nil otherwise
 function helpers.first_nonempty_line(file)
   for k,v in pairs(helpers.lines_from(file)) do

-    if #v then return v end 
+    if #v then return v end

   end
   return nil
 end
   end
   return nil
 end


@@ -73,13 +88,50 @@ end
 
 helpers.timer_table = {}
 
 
 helpers.timer_table = {}
 

-function helpers.newtimer(name, timeout, fun, nostart)
-    helpers.timer_table[name] = capi.timer({ timeout = timeout })
+function helpers.newtimer(name, timeout, fun, nostart, stoppable)
+    if not name or #name == 0 then return end
+    name = (stoppable and name) or timeout
+    if not helpers.timer_table[name] then
+        helpers.timer_table[name] = timer({ timeout = timeout })
+        helpers.timer_table[name]:start()
+    end

     helpers.timer_table[name]:connect_signal("timeout", fun)
     helpers.timer_table[name]:connect_signal("timeout", fun)

-    helpers.timer_table[name]:start()

     if not nostart then
         helpers.timer_table[name]:emit_signal("timeout")
     end
     if not nostart then
         helpers.timer_table[name]:emit_signal("timeout")
     end

+    return stoppable and helpers.timer_table[name]
+end
+
+-- }}}
+
+-- {{{ Pipe operations
+
+-- run a command and execute a function on its output (asynchronous pipe)
+-- @param cmd the input command
+-- @param callback function to execute on cmd output
+-- @return cmd PID
+function helpers.async(cmd, callback)
+    return spawn.easy_async(cmd,
+    function (stdout, stderr, reason, exit_code)
+        callback(stdout, exit_code)
+    end)
+end
+
+-- like above, but call spawn.easy_async with a shell
+function helpers.async_with_shell(cmd, callback)
+    return spawn.easy_async_with_shell(cmd,
+    function (stdout, stderr, reason, exit_code)
+        callback(stdout, exit_code)
+    end)
+end
+
+-- run a command and execute a function on its output line by line
+function helpers.line_callback(cmd, callback)
+    return spawn.with_line_callback(cmd, {
+        stdout = function (line)
+            callback(line)
+        end,
+    })

 end
 
 -- }}}
 end
 
 -- }}}


@@ -98,4 +150,58 @@ end
 
 -- }}}
 
 
 -- }}}
 

+-- {{{ Misc
+
+-- check if an element exist on a table
+function helpers.element_in_table(element, tbl)
+    for _, i in pairs(tbl) do
+        if i == element then
+            return true
+        end
+    end
+    return false
+end
+
+-- iterate over table of records sorted by keys
+function helpers.spairs(t)
+    -- collect the keys
+    local keys = {}
+    for k in pairs(t) do keys[#keys+1] = k end
+
+    table.sort(keys)
+
+    -- return the iterator function
+    local i = 0
+    return function()
+        i = i + 1
+        if keys[i] then
+            return keys[i], t[keys[i]]
+        end
+    end
+end
+
+-- create the partition of singletons of a given set
+-- example: the trivial partition set of {a, b, c}, is {{a}, {b}, {c}}
+function helpers.trivial_partition_set(set)
+    local ss = {}
+    for _,e in pairs(set) do
+        ss[#ss+1] = {e}
+    end
+    return ss
+end
+
+-- creates the powerset of a given set
+function helpers.powerset(s)
+    if not s then return {} end
+    local t = {{}}
+    for i = 1, #s do
+        for j = 1, #t do
+            t[#t+1] = {s[i],unpack(t[j])}
+        end
+    end
+    return t
+end
+
+-- }}}
+

 return helpers
 return helpers