fs/alsabar: small fixes

[etc/awesome.git] / helpers.lua

diff --git a/helpers.lua b/helpers.lua
index af6443fb88a51f4c4c0083b82f66465241ea211b..9755dc0405e072980b6e937d8e47acb8206c0432 100644 (file)
--- a/helpers.lua
+++ b/helpers.lua
@@ -2,17 +2,21 @@
 --[[
                                                   
      Licensed under GNU General Public License v2 
-      * (c) 2013,      Luke Bonham                
-      * (c) 2010-2012, Peter Hofmann              
+      * (c) 2013, Luke Bonham                     
                                                   
 --]]
 
-local debug  = require("debug")
 
-local capi   = { timer = timer }
-local io     = { open = io.open,
-                 lines = io.lines }
-local rawget = rawget
+local debug      = require("debug")
+local io         = { lines = io.lines,
+                     open  = io.open,
+                     popen = io.popen }
+local rawget     = rawget
+local table      = { sort  = table.sort }
+
+local easy_async = require("awful.spawn").easy_async
+local timer      = require("gears.timer")
+local wibox      = require("wibox")
 
 -- Lain helper functions for internal use
 -- lain.helpers
@@ -33,25 +37,40 @@ end
 
 -- {{{ File operations
 
--- see if the file exists
+-- see if the file exists and is readable
 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
 
-
--- 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
-  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
 
+-- 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)
@@ -62,7 +81,7 @@ end
 -- 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
@@ -73,10 +92,13 @@ end
 
 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)
+    local name = 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]:start()
     if not nostart then
         helpers.timer_table[name]:emit_signal("timeout")
     end
@@ -84,6 +106,31 @@ end
 
 -- }}}
 
+-- {{{ Pipe operations
+
+-- return the full output of an input command (synchronous pipe)
+-- @param cmd the input command
+-- @return command output (string)
+function helpers.read_pipe(cmd)
+   local f = io.popen(cmd)
+   local output = f:read("*all")
+   f:close()
+   return output
+end
+
+-- 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 easy_async(cmd,
+    function (stdout, stderr, reason, exit_code)
+        callback(stdout)
+    end)
+end
+
+-- }}}
+
 -- {{{ A map utility
 
 helpers.map_table = {}
@@ -98,4 +145,44 @@ 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 a lain textbox widget
+function helpers.make_widget_textbox()
+    local w = wibox.widget.textbox('')
+    local t = wibox.widget.base.make_widget(w)
+    t.widget = w
+    return t
+end
+
+-- }}}
+
 return helpers