src/ffluci/util.lua

   1 --[[
   2 FFLuCI - Utility library
   3
   4 Description:
   5 Several common useful Lua functions
   6
   7 FileId:
   8 $Id$
   9
  10 License:
  11 Copyright 2008 Steven Barth <steven@midlink.org>
  12
  13 Licensed under the Apache License, Version 2.0 (the "License");
  14 you may not use this file except in compliance with the License.
  15 You may obtain a copy of the License at
  16
  17         http://www.apache.org/licenses/LICENSE-2.0
  18
  19 Unless required by applicable law or agreed to in writing, software
  20 distributed under the License is distributed on an "AS IS" BASIS,
  21 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  22 See the License for the specific language governing permissions and
  23 limitations under the License.
  24
  25 ]]--
  26
  27 module("ffluci.util", package.seeall)
  28
  29 -- Checks whether a table has an object "value" in it
  30 function contains(table, value)
  31         for k,v in pairs(table) do
  32                 if value == v then
  33                         return true
  34                 end
  35         end
  36         return false
  37 end
  38
  39
  40 -- Dumps a table to stdout (useful for testing and debugging)
  41 function dumptable(t, i)
  42         i = i or 0
  43         for k,v in pairs(t) do
  44                 print(string.rep("\t", i) .. k, v)
  45                 if type(v) == "table" then
  46                         dumptable(v, i+1)
  47                 end
  48         end
  49 end
  50
  51
  52 -- Escapes all occurences of c in s
  53 function escape(s, c)
  54         c = c or "\\"
  55         return s:gsub(c, "\\" .. c)
  56 end
  57
  58
  59 -- Runs "command" and returns its output
  60 function exec(command, return_array)
  61         local pp   = io.popen(command)
  62         local data = nil
  63
  64         if return_array then
  65                 local line = ""
  66                 data = {}
  67
  68                 while true do
  69                         line = pp:read()
  70                         if (line == nil) then break end
  71                         table.insert(data, line)
  72                 end
  73                 pp:close()
  74         else
  75                 data = pp:read("*a")
  76                 pp:close()
  77         end
  78
  79         return data
  80 end
  81
  82 -- Populate obj in the scope of f as key
  83 function extfenv(f, key, obj)
  84         local scope = getfenv(f)
  85         scope[key] = obj
  86         setfenv(f, scope)
  87 end
  88
  89
  90 -- Updates the scope of f with "extscope"
  91 function updfenv(f, extscope)
  92         local scope = getfenv(f)
  93         for k, v in pairs(extscope) do
  94                 scope[k] = v
  95         end
  96         setfenv(f, scope)
  97 end
  98
  99 -- Returns the filename of the calling script
 100 function __file__()
 101         return debug.getinfo(2, 'S').source:sub(2)
 102 end