contrib/bsdinstaller-1.1.6/src/lib/lua/filename/filename.lua

   1 -- $Id: filename.lua,v 1.1 2005/03/29 20:58:31 cpressey Exp $
   2
   3 module("filename")
   4
   5 local POSIX = require("posix")
   6
   7 --[[----------]]--
   8 --[[ FileName ]]--
   9 --[[----------]]--
  10
  11 --
  12 -- Package of routines for manipulating filenames.
  13 -- Also contains convenience functions for querying the
  14 -- status of files in the filesystem named by those filenames.
  15 --
  16
  17 FileName = {}
  18
  19 --
  20 -- Add a trailing slash to a pathname, if needed.
  21 --
  22 FileName.add_trailing_slash = function(path)
  23         if string.sub(path, -1) ~= "/" then
  24                 return path .. "/"
  25         else
  26                 return path
  27         end
  28 end
  29
  30 --
  31 -- Remove any leading slash from a pathname.
  32 --
  33 FileName.remove_leading_slash = function(path)
  34         if string.sub(path, 1, 1) == "/" then
  35                 return string.sub(path, 2)
  36         else
  37                 return path
  38         end
  39 end
  40
  41 --
  42 -- Remove the trailing slash of a pathname, if present.
  43 --
  44 FileName.remove_trailing_slash = function(path)
  45         if string.sub(path, -1) == "/" then
  46                 return string.sub(path, 1, string.len(path) - 1)
  47         else
  48                 return path
  49         end
  50 end
  51
  52 --
  53 -- Pure Lua version of dirname.
  54 --
  55 FileName.dirname = function(path)
  56         while true do
  57                 if path == "" or
  58                    string.sub(path, -1) == "/" or
  59                    string.sub(path, -2) == "/." or
  60                    string.sub(path, -3) == "/.." or
  61                    (string.sub(path, -1) == "." and
  62                     string.len(path) == 1) or
  63                    (string.sub(path, -2) == ".." and
  64                     string.len(path) == 2) then
  65                         break
  66                 end
  67                 path = string.sub(path, 1, -2)
  68         end
  69         if path == "" then
  70                 path = "."
  71         end
  72         if string.sub(path, -1) ~= "/" then
  73                 path = path .. "/"
  74         end
  75
  76         return path
  77 end
  78
  79 --
  80 -- Pure Lua version of basename.
  81 --
  82 FileName.basename = function(path)
  83         local i = string.len(path)
  84
  85         while string.sub(path, i, i) == "/" and i > 0 do
  86                 path = string.sub(path, 1, i - 1)
  87                 i = i - 1
  88         end
  89         while i > 0 do
  90                 if string.sub(path, i, i) == "/" then
  91                         break
  92                 end
  93                 i = i - 1
  94         end
  95         if i > 0 then
  96                 path = string.sub(path, i + 1, -1)
  97         end
  98         if path == "" then
  99                 path = "/"
 100         end
 101
 102         return path
 103 end
 104
 105 --
 106 -- Query file status in the underlying file system.
 107 -- If the given file is the thing the test is asking for, return 'true'.
 108 -- If it's not that type of thing, but it does exist, return 'false'.
 109 -- If it doesn't even exist, return 'nil'.
 110 --
 111
 112 FileName.is_dir = function(path)
 113         local stat = POSIX.stat(path)
 114
 115         if not stat then
 116                 return nil
 117         else
 118                 return stat.type == "directory"
 119         end
 120 end
 121
 122 FileName.is_file = function(path)
 123         local stat = POSIX.stat(path)
 124
 125         if not stat then
 126                 return nil
 127         else
 128                 return stat.type == "regular"
 129         end
 130 end
 131
 132 FileName.is_program = function(path)
 133         local stat = POSIX.stat(path)
 134
 135         if not stat then
 136                 return nil
 137         else
 138                 return stat.type == "regular" and
 139                        string.sub(stat.mode, 9, 9) == "x"
 140         end
 141 end
 142
 143 return FileName