Looking to a way in lua to get last time an file was modified, on windows
I have seen this post How can I get last modified timestamp in Lua
But is a solution for linux :/ can I use io.popen to get the string in windows also?
function get_file_time(filepath)
local pipe = io.popen('dir /4/tw "'..filepath..'"')
local output = pipe:read"*a"
pipe:close()
return output:match"\n(%d.-:%S*)"
end
local filepath = [[C:\path\to\your\file.ext]] -- file must exist
print(get_file_time(filepath))
Use luafilesystem the git https://github.com/keplerproject/luafilesystem
lfs.attributes(<your file path>).modification is what you searching for
it also work for both Windows and Linux
the manual https://keplerproject.github.io/luafilesystem/manual.html
Related
I want to reload my neovim configuration files with just a couple of keystrokes instead of having to restart the app. I was able to do this when using an init.vim with the following command:
nnoremap <leader>sv <cmd>source $MYVIMRC<CR>
$MYVIMRC points correctly to my config entry point.
The problem is that I switched to using lua, and now I can't do the same. I have read the docs and tried variants of the following without success:
util.nnoremap("<leader>sv", "<cmd>luafile $MYVIMRC<CR>")
Finally, I found a solution doing this:
function load(name)
local path = vim.fn.stdpath('config') .. '/lua/' .. name .. '.lua'
dofile(path)
end
load('plugins')
load('config/mapping')
load('lsp/init')
Which is buggy and feels wrong.
Is there any way to do this? I read the example in vimpeccable, but I want to see the other available options since I would rather not install another plugin.
I know that plenary includes a function to reload modules, but I don't understand how to use it. A complete example of that would be good too since I already use plenary in my config.
I am a new Neovim user, so I guess my solution may not work for some edge cases.
This function flushes the module of current buffer:
local cfg = vim.fn.stdpath('config')
Flush = function()
local s = vim.api.nvim_buf_get_name(0)
if string.match(s, '^' .. cfg .. '*') == nil then
return
end
s = string.sub(s, 6 + string.len(cfg), -5)
local val = string.gsub(s, '%/', '.')
package.loaded[val] = nil
end
You can call it whenever you write to a buffer with this autocommand:
autocmd BufWrite *.lua,*vim call v:lua.Flush()
This way, after you execute :source $MYVIMRC it will also reload changed Lua modules.
For me, I want to learn how VM's work and if they can only be ran on Mac. I've found a bytecode vm (from lua) in roblox studio as one of the scripts. I'm very confused on how to use it, its nothing like i've used before. Here it is:
https://web.roblox.com/library/117513593/EpicLua-Lua-5-1-VM
Also if you could tell me more about VM's that would also help me during this process.
Looks like it's plug-and-play.
Require the module in a script/command line on Roblox. It will return a function which you can call with a string and desired environment (optional), which again returns a function you can run to run the string-code.
Example:
local LoadString = require(module)
local func = LoadString("print('Hello world!')")
func() -- prints "Hello world!"
i've one question about lua and io library.
i've this simple function to get file size:
function checkisoLIMG(file)
local iso = assert(io.open(file, "rb"));
if (iso) then
local size = iso:seek("end");
iso:close();
return size;
else
return "error";
end
end
When i try to get the size of a big file (about 3GB or 4GB) the function return nil or -1, but with small files works fine. Someone know how to fix this? or any script to get file size.
The problem is io.seek, because the program open file without problem, and i can seek to a position lower than 2147483647 (just 1 byte less than 2GB), but when i try to see to 2GB or bigger position then fails.
Thanks in advance
It depends on Lua version and OS.
-- Program
print(io.open[[D:\_Best Films\The Grudge 1,2\Proklyatie.2004.x264.BDRip.720p.mkv]]:seek'end')
-- Output on Lua 5.2.1 / Windows
5706609998
-- Output on Lua 5.1.4 / Windows
nil Invalid argument 22
The is no pure Lua workaround for this issue.
I don't know what is causing the particular error in your code but if I wanted to know the size of a file I would use the LuaFilesystem library. Its not part of the basic Lua standard libraries but its the most commonly used filesystem library I know. It comes bundled with the LuaForWindows distribution and is also easy to install with Luarocks.
local lfs = require 'lfs'
function getFileSize(filename)
local attrs = lfs.attributes(filename)
if not attrs then error("File not found") end
return attrs.size
end
I need to use Lua to run a binary program that may write something in its stdout and also returns a status code (also known as "exit status").
I searched the web and couldn't find something that does what I need. However I found out that in Lua:
os.execute() returns the status code
io.popen() returns a file handler that can be used to read process output
However I need both. Writing a wrapper function that runs both functions behind the scene is not an option because of process overhead and possibly changes in result on consecutive runs. I need to write a function like this:
function run(binpath)
...
return output,exitcode
end
Does anyone has an idea how this problem can be solved?
PS. the target system rung Linux.
With Lua 5.2 I can do the following and it works
-- This will open the file
local file = io.popen('dmesg')
-- This will read all of the output, as always
local output = file:read('*all')
-- This will get a table with some return stuff
-- rc[1] will be true, false or nil
-- rc[3] will be the signal
local rc = {file:close()}
I hope this helps!
I can't use Lua 5.2, I use this helper function.
function execute_command(command)
local tmpfile = '/tmp/lua_execute_tmp_file'
local exit = os.execute(command .. ' > ' .. tmpfile .. ' 2> ' .. tmpfile .. '.err')
local stdout_file = io.open(tmpfile)
local stdout = stdout_file:read("*all")
local stderr_file = io.open(tmpfile .. '.err')
local stderr = stderr_file:read("*all")
stdout_file:close()
stderr_file:close()
return exit, stdout, stderr
end
This is how I do it.
local process = io.popen('command; echo $?') -- echo return code of last run command
local lastline
for line in process:lines() do
lastline = line
end
print(lastline) -- the return code is the last line of output
If the last line has fixed length you can read it directly using file:seek("end", -offset), offset should be the length of the last line in bytes.
This functionality is provided in C by pclose.
Upon successful return, pclose() shall return the termination status
of the command language interpreter.
The interpreter returns the termination status of its child.
But Lua doesn't do this right (io.close always returns true). I haven't dug into these threads but some people are complaining about this brain damage.
http://lua-users.org/lists/lua-l/2004-05/msg00005.html
http://lua-users.org/lists/lua-l/2011-02/msg00387.html
If you're running this code on Win32 or in a POSIX environment, you could try this Lua extension: http://code.google.com/p/lua-ex-api/
Alternatively, you could write a small shell script (assuming bash or similar is available) that:
executes the correct executable, capturing the exit code into a shell variable,
prints a newline and terminal character/string onto standard out
prints the shell variables value (the exit code) onto standard out
Then, capture all the output of io.popen and parse backward.
Full disclosure: I'm not a Lua developer.
yes , your are right that os.execute() has returns and it's very simple if you understand how to run your command with and with out lua
you also may want to know how many variables it returns , and it might take a while , but i think you can try
local a, b, c, d, e=os.execute(-what ever your command is-)
for my example a is an first returned argument , b is the second returned argument , and etc.. i think i answered your question right, based off of what you are asking.
I'm trying to script a lua file to check if a certain file is open. Then I want it to close that file if it is open. I know how to check if the file exist but I need to know how to check if the file is open, meaning the file is running.
Lua, like C, C++, and pretty much every other language, can only close files that it opens itself. You cannot close files open by other people (not with standard Lua calls); this would be incredibly rude.
So you can't test to see if a file is opened by someone else. Nor can you close their file. There may be system API calls you could make to do this, but you would have to give Lua scripts access to those APIs yourself. Lua's standard libraries can't do this.
Sounds like you want to check which if any programs have a given file open.
first thing that comes to mind is parsing the output of lsof on linux.
fd = io.popen("lsof path/to/my/file")
fileopened = (#fd:read("a*") > 0)
Kind of a hacky way to do it, but it works:
processname = "process_name_here.exe"
filedata = io.popen("tasklist /NH /FO CSV /FI \"IMAGENAME eq "..processname.."\"")
output = filedata:read()
filedata:close()
if output ~= "INFO: No tasks are running which match the specified criteria." then
-- Program is running. Close the program
os.execute("taskkill -im "..processname)
else
-- Program is not running
end
Just make sure to replace "process_name_here.exe" with the process name that shows up in task manager
Alternatively you can just use this to close it without checking if it was actually running:
os.execute("taskkill -im process_name_here.exe")