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File IO supporting functions to make reading and writing files easier.
-- io operations
local json = require("json")
local lfs = require( "lfs" )
local iolib = {}
--[[ FACILITIES ]]--
local function toDate( timestamp )
return os.date( "!%Y-%m-%d %H:%M:%S", timestamp )
end
iolib.toDate = toDate
iolib.isdebug = true
--[[ ENUMS ]]--
iolib.stacktype = {
fifo = 1,
lifo = 2,
}
--[[ ATTRIBUTES ]]--
local function fileAttributes( filename, base )
local path = system.pathForFile( filename, base )
return lfs.attributes( path )
end
iolib.fileAttributes = fileAttributes
-- returns the resource attributes
local function resourceAttributes( filename )
return fileAttributes( filename, system.ResourceDirectory )
end
iolib.resourceAttributes = resourceAttributes
-- returns true if the document attributes
local function docAttributes( filename )
return fileAttributes( filename, system.DocumentsDirectory )
end
iolib.docAttributes = docAttributes
-- returns true if the temporary file attributes
local function tempAttributes( filename )
return fileAttributes( filename, system.TemporaryDirectory )
end
iolib.tempAttributes = tempAttributes
-- returns true if the cached file attributes
local function cacheAttributes( filename )
return fileAttributes( filename, system.CachesDirectory )
end
iolib.cacheAttributes = cacheAttributes
--[[ EXISTS ]]--
-- returns true if the file exists
local function fileExists( filename, base )
local path = system.pathForFile( filename, base )
if (path == nil) then return false end
local file = io.open( path, "r" )
if file then
io.close(file)
return true
end
return false
end
iolib.fileExists = fileExists
-- returns true if the resource exists
local function resourceExists( filename )
return fileExists( filename, system.ResourceDirectory )
end
iolib.resourceExists = resourceExists
-- returns true if the document exists
local function docExists( filename )
return fileExists( filename, system.DocumentsDirectory )
end
iolib.docExists = docExists
-- returns true if the temporary file exists
local function tempExists( filename )
return fileExists( filename, system.TemporaryDirectory )
end
iolib.tempExists = tempExists
-- returns true if the cached file exists
local function cacheExists( filename )
return fileExists( filename, system.CachesDirectory )
end
iolib.cacheExists = cacheExists
--[[ DELETE ]]--
-- deletes a file
function removeFile( filename, base )
local path = system.pathForFile( filename, base )
if (iolib.isdebug) then print("removeFile:",path) end
return os.remove( path )
end
iolib.removeFile = removeFile
-- removes file if the resource exists
local function removeResource( filename )
return removeFile( filename, system.ResourceDirectory )
end
iolib.removeResource = removeResource
-- removes file if the document exists
local function removeDoc( filename )
return removeFile( filename, system.DocumentsDirectory )
end
iolib.removeDoc = removeDoc
-- removes file if the temporary file exists
local function removeTemp( filename )
return removeFile( filename, system.TemporaryDirectory )
end
iolib.removeTemp = removeTemp
-- removes file if the cached file exists
local function removeCache( filename )
return removeFile( filename, system.CachesDirectory )
end
iolib.removeCache = removeCache
--[[ WRITE / READ ]]--
-- will write data to the specified application directory
function write( filename, base, data )
if (type(data) == "table") then
data = json.prettify( json.encode( data ) )
end
local path = system.pathForFile( filename, base )
if (iolib.isdebug) then print("Write Path:",path) end
local file = io.open( path, "w" )
if (data ~= nil) then
file:write( tostring( data ) )
if (iolib.isdebug) then print(tostring(data)) end
end
io.close( file )
file = nil
return nil
end
iolib.write = write
-- will read data from the specified application directory
-- will auto-decode json data when 'decode' is true or filename ends in '.json'
function read( filename, base, decode )
local path = system.pathForFile( filename, base )
if (iolib.isdebug) then print("Read Path:",path) end
local file, errStr = io.open( path, "rb" )
local data = nil
if (file) then
data = file:read( "*a" )
io.close( file )
end
file = nil
if (data ~= nil) then
local decoded = json.decode( data )
if (decoded ~= nil and (decode or (decode == nil and filename:ends(".json")))) then
data = decoded
end
end
return data, success
end
iolib.read = read
-- reads from the read-only resource directory
function rResource( filename )
if (data) then
return nil
else
return read( filename, system.ResourceDirectory )
end
end
iolib.rResource = rResource
-- writes and reads to/from the permanent documents directory
function wrDocs( filename, data )
if (data == nil or type(data) == "boolean") then
return read( filename, system.DocumentsDirectory )
else
return write( filename, system.DocumentsDirectory, data )
end
end
iolib.wrDocs = wrDocs
-- writes and reads to/from the short-term temporary directory
function wrTemp( filename, data )
if (data == nil or type(data) == "boolean") then
return read( filename, system.TemporaryDirectory )
else
return write( filename, system.TemporaryDirectory, data )
end
end
iolib.wrTemp = wrTemp
-- writes and reads to/from the cache directory (longer life than temp)
function wrCache( filename, data )
if (data == nil or type(data) == "boolean") then
return read( filename, system.CachesDirectory )
else
return write( filename, system.CachesDirectory, data )
end
end
iolib.wrCache = wrCache
--[[ PUT / PULL ]]--
-- put named single value into permanent store, overwriting previous value
local function put( name, value )
local filename = "putpull"..tostring(name)..".txt"
wrTemp( filename, tostring(value) )
end
iolib.put = put
-- pull named single value from permanent store, removing the store
local function pull( name )
local filename = "putpull"..tostring(name)..".txt"
local value = wrTemp( filename )
removeTemp( tostring( filename ) )
return value
end
iolib.pull = pull
--[[ PUSH / POP ]]--
-- pushes an item onto the permanent named list
local function push( listname, stacktype, item )
local filename = listname..".json"
local list = wrDocs( filename )
if (list == nil) then
list = {}
else
list = json.decode( list )
end
list[ #list+1 ] = item
wrDocs( filename, json.encode( list ) )
return #list
end
iolib.push = push
-- reads an item from the permanent named list and optionally removes it
local function pop( listname, stacktype, isRemove )
local filename = listname..".json"
local list = wrDocs( filename )
if (list == nil) then
list = {}
else
list = json.decode( list )
end
local item
if (#list > 0) then
if (stacktype == iolib.stacktype.fifo) then
item = list[1]
if (isRemove) then
table.remove( list, 1 )
end
elseif (stacktype == iolib.stacktype.lifo) then
item = list[ #list ]
if (isRemove) then
list[ #list ] = nil
end
end
wrDocs( filename, json.encode( list ) )
end
return item, #list
end
iolib.pop = pop
--[[ DIRECTORY LISTING ]]--
local function directoryListing( foldername, base, filter )
-- Get raw path to the app documents directory
local doc_path = system.pathForFile( foldername or "", base )
local tbl = {}
for file in lfs.dir( doc_path ) do
-- "file" is the current file or directory name
if (filter == nil or filter == "" or string.find( file, filter )) then
if (iolib.isdebug) then print( "Found file: " .. file ) end
tbl[#tbl+1] = file
end
end
return tbl
end
-- returns the resource folder contents
local function resourceListing( foldername, filter )
return directoryListing( foldername, system.ResourceDirectory, filter )
end
iolib.resourceListing = resourceListing
-- returns true if the document contents
local function docListing( foldername, filter )
return directoryListing( foldername, system.DocumentsDirectory, filter )
end
iolib.docListing = docListing
-- returns true if the temporary file contents
local function tempListing( foldername, filter )
return directoryListing( foldername, system.TemporaryDirectory, filter )
end
iolib.tempListing = tempListing
-- returns true if the cached file contents
local function cacheListing( foldername, filter )
return directoryListing( foldername, system.CachesDirectory, filter )
end
iolib.cacheListing = cacheListing
--[[ CREATE DIRECTORY ]]--
local function createDirectory( foldername, base )
-- Get raw path to documents directory
local docs_path = system.pathForFile( "", base )
-- Change current working directory
local success = lfs.chdir( docs_path ) -- Returns true on success
local new_folder_path
if ( success ) then
lfs.mkdir( foldername )
new_folder_path = lfs.currentdir() .. "/" .. foldername
return true, new_folder_path
end
return false
end
local function createDocDir( foldername )
return createDirectory( foldername, system.DocumentsDirectory )
end
iolib.createDocDir = createDocDir
local function createTempDir( foldername )
return createDirectory( foldername, system.TemporaryDirectory )
end
iolib.createTempDir = createTempDir
return iolib
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