libs/core/luasrc/fs.lua

   1 --[[
   2 LuCI - Filesystem tools
   3
   4 Description:
   5 A module offering often needed filesystem manipulation 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 --- LuCI filesystem library.
  28 module("luci.fs", package.seeall)
  29
  30 require("posix")
  31
  32 --- Test for file access permission on given path.
  33 -- @class               function
  34 -- @name                access
  35 -- @param str   String value containing the path
  36 -- @return              Number containing the return code, 0 on sucess or nil on error
  37 -- @return              String containing the error description (if any)
  38 -- @return              Number containing the os specific errno (if any)
  39 access = posix.access
  40
  41 --- Evaluate given shell glob pattern and return a table containing all matching
  42 -- file and directory entries.
  43 -- @class                       function
  44 -- @name                        glob
  45 -- @param filename      String containing the path of the file to read
  46 -- @return                      Table containing file and directory entries or nil if no matches
  47 -- @return                      String containing the error description (if no matches)
  48 -- @return                      Number containing the os specific errno (if no matches)
  49 glob = posix.glob
  50
  51 --- Checks wheather the given path exists and points to a regular file.
  52 -- @param filename      String containing the path of the file to read
  53 -- @return                      Boolean indicating wheather given path points to regular file
  54 function isfile(filename)
  55         return posix.stat(filename, "type") == "regular"
  56 end
  57
  58 --- Read the whole content of the given file into memory.
  59 -- @param filename      String containing the path of the file to read
  60 -- @return                      String containing the file contents or nil on error
  61 -- @return                      String containing the error message on error
  62 function readfile(filename)
  63         local fp, err = io.open(filename)
  64
  65         if fp == nil then
  66                 return nil, err
  67         end
  68
  69         local data = fp:read("*a")
  70         fp:close()
  71         return data
  72 end
  73
  74 --- Write the contents of given string to given file.
  75 -- @param filename      String containing the path of the file to read
  76 -- @param data          String containing the data to write
  77 -- @return                      Boolean containing true on success or nil on error
  78 -- @return                      String containing the error message on error
  79 function writefile(filename, data)
  80         local fp, err = io.open(filename, "w")
  81
  82         if fp == nil then
  83                 return nil, err
  84         end
  85
  86         fp:write(data)
  87         fp:close()
  88
  89         return true
  90 end
  91
  92 --- Get the last modification time of given file path in Unix epoch format.
  93 -- @param path  String containing the path of the file or directory to read
  94 -- @return              Number containing the epoch time or nil on error
  95 -- @return              String containing the error description (if any)
  96 -- @return              Number containing the os specific errno (if any)
  97 function mtime(path)
  98         return posix.stat(path, "mtime")
  99 end
 100
 101 --- Return the last element - usually the filename - from the given path with
 102 -- the directory component stripped.
 103 -- @class               function
 104 -- @name                basename
 105 -- @param path  String containing the path to strip
 106 -- @return              String containing the base name of given path
 107 -- @see                 dirname
 108 basename = posix.basename
 109
 110 --- Return the directory component of the given path with the last element
 111 -- stripped of.
 112 -- @class               function
 113 -- @name                dirname
 114 -- @param path  String containing the path to strip
 115 -- @return              String containing the directory component of given path
 116 -- @see                 basename
 117 dirname = posix.dirname
 118
 119 --- Return a table containing all entries of the specified directory.
 120 -- @class               function
 121 -- @name                dir
 122 -- @param path  String containing the path of the directory to scan
 123 -- @return              Table containing file and directory entries or nil on error
 124 -- @return              String containing the error description on error
 125 -- @return              Number containing the os specific errno on error
 126 dir = posix.dir
 127
 128 --- Create a new directory, recursively on demand.
 129 -- @param path          String with the name or path of the directory to create
 130 -- @param recursive     Create multiple directory levels (optional, default is true)
 131 -- @return                      Number with the return code, 0 on sucess or nil on error
 132 -- @return                      String containing the error description on error
 133 -- @return                      Number containing the os specific errno on error
 134 function mkdir(path, recursive)
 135         if recursive then
 136                 local base = "."
 137
 138                 if path:sub(1,1) == "/" then
 139                         base = ""
 140                         path = path:gsub("^/+","")
 141                 end
 142
 143                 for elem in path:gmatch("([^/]+)/*") do
 144                         base = base .. "/" .. elem
 145
 146                         local stat = posix.stat( base )
 147
 148                         if not stat then
 149                                 local stat, errmsg, errno = posix.mkdir( base )
 150
 151                                 if type(stat) ~= "number" or stat ~= 0 then
 152                                         return stat, errmsg, errno
 153                                 end
 154                         else
 155                                 if stat.type ~= "directory" then
 156                                         return nil, base .. ": File exists", 17
 157                                 end
 158                         end
 159                 end
 160
 161                 return 0
 162         else
 163                 return posix.mkdir( path )
 164         end
 165 end
 166
 167 --- Remove the given empty directory.
 168 -- @class               function
 169 -- @name                rmdir
 170 -- @param path  String containing the path of the directory to remove
 171 -- @return              Number with the return code, 0 on sucess or nil on error
 172 -- @return              String containing the error description on error
 173 -- @return              Number containing the os specific errno on error
 174 rmdir = posix.rmdir
 175
 176 --- Get information about given file or directory.
 177 -- @class               function
 178 -- @name                stat
 179 -- @param path  String containing the path of the directory to query
 180 -- @return              Table containing file or directory properties or nil on error
 181 -- @return              String containing the error description on error
 182 -- @return              Number containing the os specific errno on error
 183 stat = posix.stat
 184
 185 --- Set permissions on given file or directory.
 186 -- @class               function
 187 -- @name                chmod
 188 -- @param path  String containing the path of the directory
 189 -- @param perm  String containing the permissions to set ([ugoa][+-][rwx])
 190 -- @return              Number with the return code, 0 on sucess or nil on error
 191 -- @return              String containing the error description on error
 192 -- @return              Number containing the os specific errno on error
 193 chmod = posix.chmod
 194
 195 --- Create a hard- or symlink from given file (or directory) to specified target
 196 -- file (or directory) path.
 197 -- @class                       function
 198 -- @name                        link
 199 -- @param path1         String containing the source path to link
 200 -- @param path2         String containing the destination path for the link
 201 -- @param symlink       Boolean indicating wheather to create a symlink (optional)
 202 -- @return                      Number with the return code, 0 on sucess or nil on error
 203 -- @return                      String containing the error description on error
 204 -- @return                      Number containing the os specific errno on error
 205 link = posix.link
 206
 207 --- Remove the given file.
 208 -- @class               function
 209 -- @name                unlink
 210 -- @param path  String containing the path of the file to remove
 211 -- @return              Number with the return code, 0 on sucess or nil on error
 212 -- @return              String containing the error description on error
 213 -- @return              Number containing the os specific errno on error
 214 unlink = posix.unlink