share/common/quvi/util.lua

   1 -- libquvi-scripts
   2 -- Copyright (C) 2010-2012  Toni Gundogdu <legatvs@gmail.com>
   3 --
   4 -- This file is part of libquvi-scripts <http://quvi.sourceforge.net/>.
   5 --
   6 -- This library is free software; you can redistribute it and/or
   7 -- modify it under the terms of the GNU Lesser General Public
   8 -- License as published by the Free Software Foundation; either
   9 -- version 2.1 of the License, or (at your option) any later version.
  10 --
  11 -- This library is distributed in the hope that it will be useful,
  12 -- but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 -- Lesser General Public License for more details.
  15 --
  16 -- You should have received a copy of the GNU Lesser General Public
  17 -- License along with this library; if not, write to the Free Software
  18 -- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 -- 02110-1301  USA
  20 --
  21
  22 local M = {}
  23
  24 --[[
  25 Check whether a string A ends with string B.
  26 Parameters:
  27   a .. String A
  28   b .. String B
  29 Returns:
  30   true if string A ends with string B.
  31 ]]--
  32 function M.ends(a, b) -- http://lua-users.org/wiki/StringRecipes
  33   return a:sub(-#b) == b
  34 end
  35
  36 --[[
  37 Compare quality properties of two media entities. Compares the height, then
  38 the width, followed by the bitrate property comparison (if it is set).
  39 Parameters:
  40   a .. Media entity A
  41   b .. Media entity B
  42 Returns:
  43   true if entity A is the higher quality, otherwise false.
  44 ]]--
  45 function M.is_higher_quality(a, b)
  46   if a.height > b.height then
  47     if a.width > b.width then
  48       if a['bitrate'] then -- Optional
  49         if a.bitrate > b.bitrate then return true end
  50       else
  51         return true
  52       end
  53     end
  54   end
  55   return false
  56 end
  57
  58 --[[
  59 Compare quality properties of two media entities. Compares the height, then
  60 the width, followed by the bitrate property comparison (if it is set).
  61 Parameters:
  62   a .. Media entity A
  63   b .. Media entity B
  64 Returns:
  65   true if entity A is the lower quality, otherwise false.
  66 ]]--
  67 function M.is_lower_quality(a, b)
  68   if a.height < b.height then
  69     if a.width < b.width then
  70       if a['bitrate'] then -- Optional
  71         if a.bitrate < b.bitrate then return true end
  72       else
  73         return true
  74       end
  75     end
  76   end
  77   return false
  78 end
  79
  80 --[[
  81 Try to match an array of patterns to a string.
  82 Parameters:
  83   t .. Array of patterns (if nil, simply return false)
  84   s .. A string
  85 Returns:
  86   true if a pattern matched, otherwise false.
  87 ]]--
  88 function M.match_any(t, s)
  89   if not s then return false end
  90   for _,p in pairs(t) do
  91     if s:match(p) then return true end
  92   end
  93   return false
  94 end
  95
  96 --[[
  97 Tokenize a string.
  98 Parameters:
  99   s .. String to tokenize
 100   p .. Pattern (e.g. "[%w-_]+")
 101 Returns:
 102   An array of tokens.
 103 ]]--
 104 function M.tokenize(s, p)
 105   return s:gmatch(p)
 106 end
 107
 108 --[[
 109 Convert a string to a timestamp.
 110 Parameters:
 111   s .. String to convert
 112 Returns:
 113   Converted string.
 114 ]]--
 115 function M.to_timestamp(s) -- Based on <http://is.gd/ee9ZTD>
 116   local p = "%a+, (%d+) (%a+) (%d+) (%d+):(%d+):(%d+)"
 117
 118   local d,m,y,hh,mm,ss = s:match(p)
 119   if not d then error('no match: date') end
 120
 121   local MON = {Jan=1, Feb=2, Mar=3, Apr=4, May=5, Jun=6, Jul=7, Aug=8,
 122                Sep=9, Oct=10, Nov=11, Dec=12}
 123
 124   local m = MON[m]
 125   local offset = os.time() - os.time(os.date("!*t"))
 126
 127   return os.time({day=d,month=m,year=y,
 128                   hour=hh,min=mm,sec=ss}) + offset
 129 end
 130
 131 --[[
 132 Decode a string.
 133 Parameters:
 134   s .. String to decode
 135 Returns:
 136   Decoded string.
 137 ]]--
 138 function M.decode(s) -- http://www.lua.org/pil/20.3.html
 139   r = {}
 140   for n,v in s:gmatch ("([^&=]+)=([^&=]+)") do
 141     n = M.unescape(n)
 142     r[n] = v
 143   end
 144   return r
 145 end
 146
 147 --[[
 148 Unescape a string.
 149 Parameters:
 150   s .. String to unescape
 151 Returns:
 152   Unescaped string
 153 ]]--
 154 function M.unescape(s) -- http://www.lua.org/pil/20.3.html
 155   s = s:gsub('+', ' ')
 156   return (s:gsub('%%(%x%x)',
 157             function(h)
 158               return string.char(tonumber(h, 16))
 159             end))
 160 end
 161
 162 --[[
 163 Unescape slashed string.
 164 Parameters:
 165   s .. String to unescape
 166 Returns:
 167   Unescaped string
 168 ]]--
 169 function M.slash_unescape(s)
 170   return (s:gsub('\\(.)', '%1'))
 171 end
 172
 173 return M
 174
 175 -- vim: set ts=2 sw=2 tw=72 expandtab: