flm01/openwrt/package/luci/host/usr/lib/lua/luci/fs.lua

271 lines
8.8 KiB
Lua

--[[
LuCI - Filesystem tools
Description:
A module offering often needed filesystem manipulation functions
FileId:
$Id: fs.lua 4104 2009-01-20 10:19:22Z Cyrus $
License:
Copyright 2008 Steven Barth <steven@midlink.org>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
]]--
local io = require "io"
local os = require "os"
local ltn12 = require "luci.ltn12"
local posix = require "posix"
local type = type
--- LuCI filesystem library.
module "luci.fs"
--- Test for file access permission on given path.
-- @class function
-- @name access
-- @param str String value containing the path
-- @return Number containing the return code, 0 on sucess or nil on error
-- @return String containing the error description (if any)
-- @return Number containing the os specific errno (if any)
access = posix.access
--- Evaluate given shell glob pattern and return a table containing all matching
-- file and directory entries.
-- @class function
-- @name glob
-- @param filename String containing the path of the file to read
-- @return Table containing file and directory entries or nil if no matches
-- @return String containing the error description (if no matches)
-- @return Number containing the os specific errno (if no matches)
glob = posix.glob
--- Checks wheather the given path exists and points to a regular file.
-- @param filename String containing the path of the file to test
-- @return Boolean indicating wheather given path points to regular file
function isfile(filename)
return posix.stat(filename, "type") == "regular"
end
--- Checks wheather the given path exists and points to a directory.
-- @param dirname String containing the path of the directory to test
-- @return Boolean indicating wheather given path points to directory
function isdirectory(dirname)
return posix.stat(dirname, "type") == "directory"
end
--- Read the whole content of the given file into memory.
-- @param filename String containing the path of the file to read
-- @return String containing the file contents or nil on error
-- @return String containing the error message on error
function readfile(filename)
local fp, err = io.open(filename)
if fp == nil then
return nil, err
end
local data = fp:read("*a")
fp:close()
return data
end
--- Write the contents of given string to given file.
-- @param filename String containing the path of the file to read
-- @param data String containing the data to write
-- @return Boolean containing true on success or nil on error
-- @return String containing the error message on error
function writefile(filename, data)
local fp, err = io.open(filename, "w")
if fp == nil then
return nil, err
end
fp:write(data)
fp:close()
return true
end
--- Copies a file.
-- @param source Source file
-- @param dest Destination
-- @return Boolean containing true on success or nil on error
function copy(source, dest)
return ltn12.pump.all(
ltn12.source.file(io.open(source)),
ltn12.sink.file(io.open(dest, "w"))
)
end
--- Renames a file.
-- @param source Source file
-- @param dest Destination
-- @return Boolean containing true on success or nil on error
function rename(source, dest)
local stat, err, code = os.rename(source, dest)
if code == 18 then
stat, err, code = copy(source, dest)
if stat then
stat, err, code = unlink(source)
end
end
return stat, err, code
end
--- Get the last modification time of given file path in Unix epoch format.
-- @param path String containing the path of the file or directory to read
-- @return Number containing the epoch time or nil on error
-- @return String containing the error description (if any)
-- @return Number containing the os specific errno (if any)
function mtime(path)
return posix.stat(path, "mtime")
end
--- Set the last modification time of given file path in Unix epoch format.
-- @param path String containing the path of the file or directory to read
-- @param mtime Last modification timestamp
-- @param atime Last accessed timestamp
-- @return 0 in case of success nil on error
-- @return String containing the error description (if any)
-- @return Number containing the os specific errno (if any)
utime = posix.utime
--- Return the last element - usually the filename - from the given path with
-- the directory component stripped.
-- @class function
-- @name basename
-- @param path String containing the path to strip
-- @return String containing the base name of given path
-- @see dirname
basename = posix.basename
--- Return the directory component of the given path with the last element
-- stripped of.
-- @class function
-- @name dirname
-- @param path String containing the path to strip
-- @return String containing the directory component of given path
-- @see basename
dirname = posix.dirname
--- Return a table containing all entries of the specified directory.
-- @class function
-- @name dir
-- @param path String containing the path of the directory to scan
-- @return Table containing file and directory entries or nil on error
-- @return String containing the error description on error
-- @return Number containing the os specific errno on error
dir = posix.dir
--- Create a new directory, recursively on demand.
-- @param path String with the name or path of the directory to create
-- @param recursive Create multiple directory levels (optional, default is true)
-- @return Number with the return code, 0 on sucess or nil on error
-- @return String containing the error description on error
-- @return Number containing the os specific errno on error
function mkdir(path, recursive)
if recursive then
local base = "."
if path:sub(1,1) == "/" then
base = ""
path = path:gsub("^/+","")
end
for elem in path:gmatch("([^/]+)/*") do
base = base .. "/" .. elem
local stat = posix.stat( base )
if not stat then
local stat, errmsg, errno = posix.mkdir( base )
if type(stat) ~= "number" or stat ~= 0 then
return stat, errmsg, errno
end
else
if stat.type ~= "directory" then
return nil, base .. ": File exists", 17
end
end
end
return 0
else
return posix.mkdir( path )
end
end
--- Remove the given empty directory.
-- @class function
-- @name rmdir
-- @param path String containing the path of the directory to remove
-- @return Number with the return code, 0 on sucess or nil on error
-- @return String containing the error description on error
-- @return Number containing the os specific errno on error
rmdir = posix.rmdir
--- Get information about given file or directory.
-- @class function
-- @name stat
-- @param path String containing the path of the directory to query
-- @return Table containing file or directory properties or nil on error
-- @return String containing the error description on error
-- @return Number containing the os specific errno on error
stat = posix.stat
--- Set permissions on given file or directory.
-- @class function
-- @name chmod
-- @param path String containing the path of the directory
-- @param perm String containing the permissions to set ([ugoa][+-][rwx])
-- @return Number with the return code, 0 on sucess or nil on error
-- @return String containing the error description on error
-- @return Number containing the os specific errno on error
chmod = posix.chmod
--- Create a hard- or symlink from given file (or directory) to specified target
-- file (or directory) path.
-- @class function
-- @name link
-- @param path1 String containing the source path to link
-- @param path2 String containing the destination path for the link
-- @param symlink Boolean indicating wheather to create a symlink (optional)
-- @return Number with the return code, 0 on sucess or nil on error
-- @return String containing the error description on error
-- @return Number containing the os specific errno on error
link = posix.link
--- Remove the given file.
-- @class function
-- @name unlink
-- @param path String containing the path of the file to remove
-- @return Number with the return code, 0 on sucess or nil on error
-- @return String containing the error description on error
-- @return Number containing the os specific errno on error
unlink = posix.unlink
--- Retrieve target of given symlink.
-- @class function
-- @name readlink
-- @param path String containing the path of the symlink to read
-- @return String containing the link target or nil on error
-- @return String containing the error description on error
-- @return Number containing the os specific errno on error
readlink = posix.readlink