I am writing a VLC extension in which i would like to open some url in a web browser( in lua of course ). So far, I have not been able to find any relevant code for opening the web browser from a lua script. Is there any way in which I can perform this task (say for example a google search of the file playing)?
I am able to create a link to the url using a dialog box, but i would like to skip this step and make it open without any user input.
I am a beginner to lua and to making VLC extentions( just started a few days back ) and have been trying things out since then.
The exact command varies between operating systems:
On Windows:
start http://example.com/
On *nix (most portable option):
xdg-open "http://example.com/"
On OSX:
open http://example.com/
The following Lua sample should work on Windows, Linux, and OSX (Though I cannot test OSX).
It works by first checking Lua's package.config for the \\ directory separator (which, afaik, is only used on windows). That should only leave us with OSes that support uname. Then I take a flying leap and assume that Mac will identify as 'Darwin', and thus anything that doesn't is *nix.
Obviously, this is somewhat less than exhaustive.
-- Attempts to open a given URL in the system default browser, regardless of Operating System.
local open_cmd -- this needs to stay outside the function, or it'll re-sniff every time...
function open_url(url)
if not open_cmd then
if package.config:sub(1,1) == '\\' then -- windows
open_cmd = function(url)
-- Should work on anything since (and including) win'95
os.execute(string.format('start "%s"', url))
end
-- the only systems left should understand uname...
elseif (io.popen("uname -s"):read'*a') == "Darwin" then -- OSX/Darwin ? (I can not test.)
open_cmd = function(url)
-- I cannot test, but this should work on modern Macs.
os.execute(string.format('open "%s"', url))
end
else -- that ought to only leave Linux
open_cmd = function(url)
-- should work on X-based distros.
os.execute(string.format('xdg-open "%s"', url))
end
end
end
open_cmd(url)
end
Related
The major operating systems seem to have a designated place to store configuration files.
On Linux it would be something like $HOME/.myprogram/data or $HOME/.config/myprogram/data, or perhaps a better practice would be to read $XDG_CONFIG_HOME.
On macOS it would be $HOME/.myprogram/data or $HOME/Library/Preferences/myprogram/data.
On Windows it would be %appdata%/myprogram/data.
How to get such value in a portable manner in Lua?
Check the existence condition of a variable with...
if (os.getenv('XDG_CONFIG_HOME')) then
os.execute('ls ' .. os.getenv('XDG_CONFIG_HOME'))
else -- Or: elseif (nextcondition) then
print('XDG_CONFIG_HOME', 'Not exists')
-- Maybe next check here?
end
But be aware that a user could start Lua with only that environment that Lua needs.
Like...
lua ()
{
env -i DISPLAY=:0 LANG='de_DE.UTF-8' TERM='xterm-256color' LUA_PATH='./lua/?.lua' LUA_CPATH='./lua/?.so' /usr/local/bin/lua "${#}"
}
Then check for XDG_CONFIG_HOME will allways fail.
Because above environment knows nothing about HOME, USER and XDG_CONFIG_HOME.
PS: I know a place too where my linux system saves configs/savegames or whatever
${HOME}/.local/share/
So i got a new keyboard wit hG-keys. (hotkeys) And i'm not familiar with lua...
So could anybody give me a very simple command that sets my pc to sleep? please?
if gkey == 7 and mkey == 1 then
if event == "G_PRESSED" then
end
end
gkeys
so gkey is the key that is pressed, and mkey is the set it uses. i can have up to 54 differint scripts/macro's.
I want to know what i have to put after the last 'then' so my pc goes to sleep.
thx ahead
edit 1:
got this:
if gkey == 1 and mkey == 3 then
if event == "G_PRESSED" then
execute("rundll32.exe powrprof.dll,SetSuspendState 0,1,0");
end
end
error is: [string "LuaVM"]:40: attempt to call global 'execute'(a nil value)
and with os.execute i get this error:
[string "LuaVM"]:40: attempt to index global 'os'(a nil value)
final answer: not possible with gseries keyboard. use a shortcut
Given the reference to G-keys and the G_PRESSED in your code snippet, I am assuming you have one of the Logitech G-Series keyboards. These keyboards can be programmed so that certain keys run Lua scripts using a custom Lua 5.1 interpreter. The documentation is included with Logitech's Gaming Software program.
According to the documentation, only some of the standard library functions are supported: the string, math and table are available. However, the io, os and debug libraries are not available.
So I doubt you'll be able to make your PC go to sleep.
EDIT in response to OP edit: the Lua library you have access to has the os library removed, so you're probably not going to be able to make your computer sleep directly.
There might be an indirect way to do this by writing something that listens for debugging messages, which you can generate with OutputDebugMessage. There's a Team Speak plugin that does this. But it's probably beyond your programming ability right now and far beyond the scope of a Stackoverflow post to explain.
You can use os.execute to run an executable from Lua.
If you google "Windows sleep command line" you'll get another Stackoverflow post which shows two ways of doing it. One requires that you turn hibernation off, the other requires that you download an additional utility (PsShutdown).
Assuming you've downloaded PsShutdown and put it somewhere in your PATH, then you can use the following to sleep the computer:
os.execute('psshutdown -d -t 0')
I use VLC media player 1.1.9 on Ubuntu 11.04. I'm trying to experiment with lua extensions for VLC; so I've added the file test.lua in ~/.local/share/vlc/lua/extensions/, which has only these two lines:
fps="25.000"
frame_duration=1/tonumber(fps)
When I run vlc with verbose output for debugging, I get (edited to split on multiple lines:):
$ vlc --verbose 2
...
[0xa213874] lua generic warning: Error loading script
~/.local/share/vlc/lua/extensions/test.lua:
.../.local/share/vlc/lua/extensions/test.lua:2:
attempt to call global 'tonumber' (a nil value)
...
Now, as far as I know, tonumber as function is part of Lua5.1 proper (Lua 5.1 Reference Manual: tonumber) - and on my system:
$ locate --regex 'lua.*so.*' | head -4
/usr/lib/libipelua.so.7.0.10
/usr/lib/liblua5.1.so
/usr/lib/liblua5.1.so.0
/usr/lib/liblua5.1.so.0.0.0
... apparently I do have Lua 5.1 installed.
So, why do I get an error on using tonumber here - and how can I use this (and other) standard functions in a VLC lua extension properly?
Documentation is sparse for VLC Lua extensions to say the least but I did find an example in the github vlc repository here: https://github.com/videolan/vlc/blob/master/share/lua/extensions/VLSub.lua
Judging from that example it appears you need to supply some basic event functions for your addon for VLC to call into when certain events happen. Some of the obvious callback handlers I've noticed:
descriptor, this should return a table that contains fields describing your addon.
activate, this seems to get called when you activate it from view menubar.
deactivate, called when you deactivate the addon from view menubar.
plus a couple of other functions like close and input_change which you can guess what they're for.
From my brief testing done on VLC 2.0.8 under Win7 it appears VLC loads the lua extension using an empty sandbox environment. This is likely the reason you're getting nil for tonumber and I'm betting none of the other standard lua functions are accessible either when you try to perform computation at this global scope.
However, if I move that code into one of the event handling functions then all those standard functions are accessible again. For example:
function descriptor()
return
{
title = "Test Ext";
version = "0.1";
author = "";
shortdesc = "Testing Lua Extension";
capabilities = {};
description = "VLC Hello Test Addon";
}
end
function activate()
print "test activating"
local fps = tonumber "25.000"
local frame_duration = 1 / fps
print(frame_duration)
return true
end
-- ...
That prints out what you would expect in the console debug log. Now the documentation (what little there is) doesn't mention any of this but what's probably happening here is VLC is injecting the standard lua functions and vlc api table into the sandboxed environment when any of these event handlers get called. But during the extension loading phase, it is done in an empty sandbox environment which explains why all those lua function calls end up being nil when you try to use it at the outter most scope.
I recommend cloning the VLC source tree from github and then performing a grep on the C source that's embedding lua to see what VLC is really doing behind the scenes. Most of the relevant code will likely be here: https://github.com/videolan/vlc/tree/master/modules/lua
Probably some extension script installed in your system overwrites the function and the Lua interpreter instance is shared between all extension scripts, so you end up not being able to call the function if that script is called before yours.
As a quick workaround, Lua being dynamically typed, you can still do things like:
1 / "25.000"
and the string will be coerced to a number.
Alternatively, you can define a tonumber equivalent like:
string_to_num = function(s) return s + 0 end
This again relies on dynamic typing.
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")
I need to reboot System through a Lua Script.
I need to write some string before the Reboot happens and need to write a string in a Lua
script once the Reboot is done.
Example :
print("Before Reboot System")
Reboot the System through Lua script
print("After Reboot System")
How would I accomplish this?
You can use os.execute to issue system commands. For Windows, it's shutdown -r, for Posix systems it's just reboot. Your Lua code will therefore look like this:
Be aware that part of the reboot command is stopping active programs, like your Lua script. That means that any data stored in RAM will be lost. You need to write any data you want to keep to disk, using, for instance, table serialization.
Unfortunately, without more knowledge of your environment, I can't tell you how to call the script again. You could be able to append a call to your script to the end of ~/.bashrc or similar.
Make sure that loading this data and starting at a point after you call your reboot function is the first thing that you do when you come back! You don't want to get stuck in an endless reboot loop where the first thing your computer does when it turns on is to turn itself off. Something like this should work:
local function is_rebooted()
-- Presence of file indicates reboot status
if io.open("Rebooted.txt", "r") then
os.remove("Rebooted.txt")
return true
else
return false
end
end
local function reboot_system()
local f = assert(io.open("Rebooted.txt", "w"))
f:write("Restarted! Call On_Reboot()")
-- Do something to make sure the script is called upon reboot here
-- First line of package.config is directory separator
-- Assume that '\' means it's Windows
local is_windows = string.find(_G.package.config:sub(1,1), "\\")
if is_windows then
os.execute("shutdown -r");
else
os.execute("reboot")
end
end
local function before_reboot()
print("Before Reboot System")
reboot_system()
end
local function after_reboot()
print("After Reboot System")
end
-- Execution begins here !
if not is_rebooted() then
before_reboot()
else
after_reboot()
end
(Warning - untested code. I didn't feel like rebooting. :)
There is no way to do what you are asking in Lua. You may be able to do this using os.execute depending on your system and set up but Lua's libraries only include what is possible in the standard c libraries which does not include operating system specific functionality like restart.