Difference between revisions of "X File"
From GiderosMobile
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__NOTOC__ | __NOTOC__ | ||
| − | |||
<!-- GIDEROSOBJ:file --> | <!-- GIDEROSOBJ:file --> | ||
| − | ''' | + | '''Supported platforms:''' [[File:Platform android.png]][[File:Platform ios.png]][[File:Platform mac.png]][[File:Platform pc.png]][[File:Platform html5.png]][[File:Platform winrt.png]][[File:Platform win32.png]]<br/> |
| − | ''' | + | '''Available since:''' Gideros 2011.6<br/> |
| − | === | + | |
| − | + | === Description === | |
| − | + | A '''file''' object is usually returned by [[io.open]] used to manipulate (read and write) files in lua. | |
| − | ''' | + | |
| − | < | + | '''NOTE:''' this page and other related '''file''' methods use an X before the name because wiki forbids creating pages starting with '''file''' |
| + | |||
| + | === Examples === | ||
| + | <syntaxhighlight lang="lua"> | ||
| + | --function to copy file | ||
| + | local function copy(src, dst) | ||
local srcf = io.open(src, "rb") | local srcf = io.open(src, "rb") | ||
local dstf = io.open(dst, "wb") | local dstf = io.open(dst, "wb") | ||
| − | local size = 2^13 | + | |
| + | local size = 2^13 -- good buffer size (8K) | ||
while true do | while true do | ||
local block = srcf:read(size) | local block = srcf:read(size) | ||
| Line 19: | Line 24: | ||
srcf:close() | srcf:close() | ||
dstf:close() | dstf:close() | ||
| − | end</ | + | end |
| + | |||
| + | --function to check if file exists | ||
| + | local function exists(file) | ||
| + | local f = io.open(file, "rb") | ||
| + | if f == nil then return false end | ||
| + | f:close() return true | ||
| + | end | ||
| + | |||
| + | --usage | ||
| + | if not exists("|D|database.db") then | ||
| + | copy("database.db", "|D|database.db") | ||
| + | end | ||
| + | </syntaxhighlight> | ||
| + | |||
{|- | {|- | ||
| style="width: 50%; vertical-align:top;"| | | style="width: 50%; vertical-align:top;"| | ||
| − | === | + | === Methods === |
| − | [[ | + | [[x_file:close|file:close]] ''closes file''<br/><!--GIDEROSMTD:file:close() closes file--> |
| − | [[ | + | [[x_file:flush|file:flush]] ''saves any written data to file''<br/><!--GIDEROSMTD:file:flush() saves any written data to file--> |
| − | [[ | + | [[x_file:lines|file:lines]] ''returns an iterator function''<br/><!--GIDEROSMTD:file:lines() returns an iterator function--> |
| − | [[ | + | [[x_file:read|file:read]] ''reads file according to given formats, returns read values or nil''<br/><!--GIDEROSMTD:file:read(format1,...) reads file according to given formats, returns read values or nil--> |
| − | [[ | + | [[x_file:seek|file:seek]] ''sets file seek pos''<br/><!--GIDEROSMTD:file:seek(whence,offset) sets file seek pos, whence="set"|"cur"|"end", defaults "curr",0, returns file pos--> |
| − | [[ | + | [[x_file:write|file:write]] ''writes strings or numbers to file''<br/><!--GIDEROSMTD:file:write(value1,...) writes strings or numbers to file--> |
| + | |||
| style="width: 50%; vertical-align:top;"| | | style="width: 50%; vertical-align:top;"| | ||
| − | === | + | === Events === |
| − | === | + | === Constants === |
|} | |} | ||
{{GIDEROS IMPORTANT LINKS}} | {{GIDEROS IMPORTANT LINKS}} | ||
Latest revision as of 07:54, 4 November 2023
Supported platforms: 
Available since: Gideros 2011.6
Description
A file object is usually returned by io.open used to manipulate (read and write) files in lua.
NOTE: this page and other related file methods use an X before the name because wiki forbids creating pages starting with file
Examples
--function to copy file
local function copy(src, dst)
local srcf = io.open(src, "rb")
local dstf = io.open(dst, "wb")
local size = 2^13 -- good buffer size (8K)
while true do
local block = srcf:read(size)
if not block then break end
dstf:write(block)
end
srcf:close()
dstf:close()
end
--function to check if file exists
local function exists(file)
local f = io.open(file, "rb")
if f == nil then return false end
f:close() return true
end
--usage
if not exists("|D|database.db") then
copy("database.db", "|D|database.db")
end
Methodsfile:close closes file |
EventsConstants |
