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 local io    = require "io"
  28 local os    = require "os"
  29 local ltn12 = require "luci.ltn12"
  30 local fs        = require "nixio.fs"
  31 local nutil = require "nixio.util"
  32
  33 local type  = type
  34
  35 --- LuCI filesystem library.
  36 module "luci.fs"
  37
  38 --- Test for file access permission on given path.
  39 -- @class               function
  40 -- @name                access
  41 -- @param str   String value containing the path
  42 -- @return              Number containing the return code, 0 on sucess or nil on error
  43 -- @return              String containing the error description (if any)
  44 -- @return              Number containing the os specific errno (if any)
  45 access = fs.access
  46
  47 --- Evaluate given shell glob pattern and return a table containing all matching
  48 -- file and directory entries.
  49 -- @class                       function
  50 -- @name                        glob
  51 -- @param filename      String containing the path of the file to read
  52 -- @return                      Table containing file and directory entries or nil if no matches
  53 -- @return                      String containing the error description (if no matches)
  54 -- @return                      Number containing the os specific errno (if no matches)
  55 function glob(...)
  56         local iter, code, msg = fs.glob(...)
  57         if iter then
  58                 return nutil.consume(iter)
  59         else
  60                 return nil, code, msg
  61         end
  62 end
  63
  64 --- Checks wheather the given path exists and points to a regular file.
  65 -- @param filename      String containing the path of the file to test
  66 -- @return                      Boolean indicating wheather given path points to regular file
  67 function isfile(filename)
  68         return fs.stat(filename, "type") == "reg"
  69 end
  70
  71 --- Checks wheather the given path exists and points to a directory.
  72 -- @param dirname       String containing the path of the directory to test
  73 -- @return                      Boolean indicating wheather given path points to directory
  74 function isdirectory(dirname)
  75         return fs.stat(dirname, "type") == "dir"
  76 end
  77
  78 --- Read the whole content of the given file into memory.
  79 -- @param filename      String containing the path of the file to read
  80 -- @return                      String containing the file contents or nil on error
  81 -- @return                      String containing the error message on error
  82 readfile = fs.readfile
  83
  84 --- Write the contents of given string to given file.
  85 -- @param filename      String containing the path of the file to read
  86 -- @param data          String containing the data to write
  87 -- @return                      Boolean containing true on success or nil on error
  88 -- @return                      String containing the error message on error
  89 writefile = fs.writefile
  90
  91 --- Copies a file.
  92 -- @param source        Source file
  93 -- @param dest          Destination
  94 -- @return                      Boolean containing true on success or nil on error
  95 copy = fs.datacopy
  96
  97 --- Renames a file.
  98 -- @param source        Source file
  99 -- @param dest          Destination
 100 -- @return                      Boolean containing true on success or nil on error
 101 rename = fs.move
 102
 103 --- Get the last modification time of given file path in Unix epoch format.
 104 -- @param path  String containing the path of the file or directory to read
 105 -- @return              Number containing the epoch time or nil on error
 106 -- @return              String containing the error description (if any)
 107 -- @return              Number containing the os specific errno (if any)
 108 function mtime(path)
 109         return fs.stat(path, "mtime")
 110 end
 111
 112 --- Set the last modification time  of given file path in Unix epoch format.
 113 -- @param path  String containing the path of the file or directory to read
 114 -- @param mtime Last modification timestamp
 115 -- @param atime Last accessed timestamp
 116 -- @return              0 in case of success nil on error
 117 -- @return              String containing the error description (if any)
 118 -- @return              Number containing the os specific errno (if any)
 119 function utime(path, mtime, atime)
 120         return fs.utimes(path, atime, mtime)
 121 end
 122
 123 --- Return the last element - usually the filename - from the given path with
 124 -- the directory component stripped.
 125 -- @class               function
 126 -- @name                basename
 127 -- @param path  String containing the path to strip
 128 -- @return              String containing the base name of given path
 129 -- @see                 dirname
 130 basename = fs.basename
 131
 132 --- Return the directory component of the given path with the last element
 133 -- stripped of.
 134 -- @class               function
 135 -- @name                dirname
 136 -- @param path  String containing the path to strip
 137 -- @return              String containing the directory component of given path
 138 -- @see                 basename
 139 dirname = fs.dirname
 140
 141 --- Return a table containing all entries of the specified directory.
 142 -- @class               function
 143 -- @name                dir
 144 -- @param path  String containing the path of the directory to scan
 145 -- @return              Table containing file and directory entries or nil on error
 146 -- @return              String containing the error description on error
 147 -- @return              Number containing the os specific errno on error
 148 function dir(...)
 149         local iter, code, msg = fs.dir(...)
 150         if iter then
 151                 local t = nutil.consume(iter)
 152                 t[#t+1] = "."
 153                 t[#t+1] = ".."
 154                 return t
 155         else
 156                 return nil, code, msg
 157         end
 158 end
 159
 160 --- Create a new directory, recursively on demand.
 161 -- @param path          String with the name or path of the directory to create
 162 -- @param recursive     Create multiple directory levels (optional, default is true)
 163 -- @return                      Number with the return code, 0 on sucess or nil on error
 164 -- @return                      String containing the error description on error
 165 -- @return                      Number containing the os specific errno on error
 166 function mkdir(path, recursive)
 167         return recursive and fs.mkdirr(path) or fs.mkdir(path)
 168 end
 169
 170 --- Remove the given empty directory.
 171 -- @class               function
 172 -- @name                rmdir
 173 -- @param path  String containing the path of the directory to remove
 174 -- @return              Number with the return code, 0 on sucess or nil on error
 175 -- @return              String containing the error description on error
 176 -- @return              Number containing the os specific errno on error
 177 rmdir = fs.rmdir
 178
 179 --- Get information about given file or directory.
 180 -- @class               function
 181 -- @name                stat
 182 -- @param path  String containing the path of the directory to query
 183 -- @return              Table containing file or directory properties or nil on error
 184 -- @return              String containing the error description on error
 185 -- @return              Number containing the os specific errno on error
 186 stat = fs.stat
 187
 188 --- Set permissions on given file or directory.
 189 -- @class               function
 190 -- @name                chmod
 191 -- @param path  String containing the path of the directory
 192 -- @param perm  String containing the permissions to set ([ugoa][+-][rwx])
 193 -- @return              Number with the return code, 0 on sucess or nil on error
 194 -- @return              String containing the error description on error
 195 -- @return              Number containing the os specific errno on error
 196 chmod = fs.chmod
 197
 198 --- Create a hard- or symlink from given file (or directory) to specified target
 199 -- file (or directory) path.
 200 -- @class                       function
 201 -- @name                        link
 202 -- @param path1         String containing the source path to link
 203 -- @param path2         String containing the destination path for the link
 204 -- @param symlink       Boolean indicating wheather to create a symlink (optional)
 205 -- @return                      Number with the return code, 0 on sucess or nil on error
 206 -- @return                      String containing the error description on error
 207 -- @return                      Number containing the os specific errno on error
 208 function link(src, dest, sym)
 209         return sym and fs.symlink(src, dest) or fs.link(src, dest)
 210 end
 211
 212 --- Remove the given file.
 213 -- @class               function
 214 -- @name                unlink
 215 -- @param path  String containing the path of the file to remove
 216 -- @return              Number with the return code, 0 on sucess or nil on error
 217 -- @return              String containing the error description on error
 218 -- @return              Number containing the os specific errno on error
 219 unlink = fs.unlink
 220
 221 --- Retrieve target of given symlink.
 222 -- @class               function
 223 -- @name                readlink
 224 -- @param path  String containing the path of the symlink to read
 225 -- @return              String containing the link target or nil on error
 226 -- @return              String containing the error description on error
 227 -- @return              Number containing the os specific errno on error
 228 readlink = fs.readlink