Using HTTP to gather a variable in php to process in lua

I need help to when I connect to a http website, i can gather a variable in the php code and then use it in lua. How can I do this?

Lua side:

local h = http.get( "your link here" )
print( h.readAll() )
h.close()

PHP:

echo "Hello World";

KingofGamesYami, on 09 July 2017 - 01:36 AM said:

Lua side:

local h = http.get( "your link here" )
print( h.readAll() )
h.close()

PHP:

echo "Hello World";

No such as if i had a variable named updatedVersion and currentVersion. Then i say if currentVersion is less than updatedVersion it does so and so. How do i do that?

Lua side:

local h = http.get( "your link here" )
print( h.readAll() == "1.0" )
h.close()

PHP:

echo "1.1";

KingofGamesYami, on 09 July 2017 - 02:56 AM said:

Lua side:

local h = http.get( "your link here" )
print( h.readAll() == "1.0" )
h.close()

PHP:

echo "1.1";

EDIT: This code does not work. All it says is False all the time when I test this and I have no clue on where i can insert code to where a pastebin can run when there is a update.

Your PHP page needs to echo the variable's value, so that it's part of the page content when you fetch it from ComputerCraft. You then make your comparison on the Lua end.

The code sample provided by KingofGamesYami should work fine. The one issue with that one is that it'll, in addition to returning false if the current version number is below the latest version, it'll also say if the current version number is above the latest version. This, in many cases, won't be an issue, but if you do push the program version above the one that's being returned by the website, it will in fact appear to be out of date. A way to prevent this is by using tonumber() to turn the version into a number before comparison and using >=/<=, though note this obviously won't work correctly if your version is laid out like 1.0.1.
(Note: Even in that case, you could remove all of the '.' in lua; though this would mean you'd have to keep the format consistent. Ie, you couldn't move from 1.0 to 1.0.1 or 1.0.0 to 1.0.01 without potentially causing issues. (like from going from 1.0.11 from 1.0.2, you'd have to put 1.0.20 as it'd be comparing 1011 to 102)


I've set up these two samples to hopefully demonstrate this &amp; help your understanding:

First webpage
https://cc.tylertwin...var/1point0.php

<?php
  header("Content-Type: text/plain");
  echo "1.0";
?>

Second webpage
https://cc.tylertwin...var/1point1.php

<?php
  header("Content-Type: text/plain");
  echo "1.1";
?>

Lua:

pastebin run 1VZga5iN
This will check both versions and tell if they're up to date with the default version (1.0). You can additionally run `pastebin run 1VZga5iN 1.1` and you'll see the issue that the 1.0 webpage will return false, as if it's out of date when the client would technically be ahead.

The "Content-Type" headers are not very necessary. It's more used to make it more viewable in a webpage (and technically more correct), because it sees it as a text document instead of an HTML page.

You can parse queries to the http server containing what variable you want to get, example:

Lua

local protocol, domain, port, file, query = 'http://', 'localhost', ':80/', 'lua-request.php?', 'version=1.0'

local handle = http.get(protocol .. domain .. port .. file .. query);
local txt = handle.readAll();
handle.close();

print(txt);

PHP File

<?php
$versions = [
  '1.0' => 'Version 1.0 is an old version',
  '1.1' => 'Version 1.1 is a new version'
];
echo $versions[$_GET['version']];

Output

Version 1.0 is an old version!

Twijn, on 10 July 2017 - 12:10 AM said:

The code sample provided by KingofGamesYami should work fine. The one issue with that one is that it'll, in addition to returning false if the current version number is below the latest version, it'll also say if the current version number is above the latest version. This, in many cases, won't be an issue, but if you do push the program version above the one that's being returned by the website, it will in fact appear to be out of date. A way to prevent this is by using tonumber() to turn the version into a number before comparison and using >=/<=, though note this obviously won't work correctly if your version is laid out like 1.0.1.
(Note: Even in that case, you could remove all of the '.' in lua; though this would mean you'd have to keep the format consistent. Ie, you couldn't move from 1.0 to 1.0.1 or 1.0.0 to 1.0.01 without potentially causing issues. (like from going from 1.0.11 from 1.0.2, you'd have to put 1.0.20 as it'd be comparing 1011 to 102)


I've set up these two samples to hopefully demonstrate this &amp; help your understanding:

First webpage
https://cc.tylertwin...var/1point0.php

<?php
  header("Content-Type: text/plain");
  echo "1.0";
?>

Second webpage
https://cc.tylertwin...var/1point1.php

<?php
  header("Content-Type: text/plain");
  echo "1.1";
?>

Lua:

pastebin run 1VZga5iN
This will check both versions and tell if they're up to date with the default version (1.0). You can additionally run `pastebin run 1VZga5iN 1.1` and you'll see the issue that the 1.0 webpage will return false, as if it's out of date when the client would technically be ahead.

The "Content-Type" headers are not very necessary. It's more used to make it more viewable in a webpage (and technically more correct), because it sees it as a text document instead of an HTML page.

EDIT: When i try using your method, it prints them at the same time for both versions being out-of-date. I copied everything that you have written down and put it in my files and they do not work. Once this does work, I'll give you full credit for this. :)/>

It might be helpful to print out the actual result. It's possible something interesting is happening, like an extra character (a space or a return or something like that).

Twijn, on 10 July 2017 - 12:10 AM said:

The code sample provided by KingofGamesYami should work fine. The one issue with that one is that it'll, in addition to returning false if the current version number is below the latest version, it'll also say if the current version number is above the latest version. This, in many cases, won't be an issue, but if you do push the program version above the one that's being returned by the website, it will in fact appear to be out of date. A way to prevent this is by using tonumber() to turn the version into a number before comparison and using >=/<=, though note this obviously won't work correctly if your version is laid out like 1.0.1.
(Note: Even in that case, you could remove all of the '.' in lua; though this would mean you'd have to keep the format consistent. Ie, you couldn't move from 1.0 to 1.0.1 or 1.0.0 to 1.0.01 without potentially causing issues. (like from going from 1.0.11 from 1.0.2, you'd have to put 1.0.20 as it'd be comparing 1011 to 102)


I've set up these two samples to hopefully demonstrate this &amp; help your understanding:

First webpage
https://cc.tylertwin...var/1point0.php

<?php
  header("Content-Type: text/plain");
  echo "1.0";
?>

Second webpage
https://cc.tylertwin...var/1point1.php

<?php
  header("Content-Type: text/plain");
  echo "1.1";
?>

Lua:

pastebin run 1VZga5iN
This will check both versions and tell if they're up to date with the default version (1.0). You can additionally run `pastebin run 1VZga5iN 1.1` and you'll see the issue that the 1.0 webpage will return false, as if it's out of date when the client would technically be ahead.

The "Content-Type" headers are not very necessary. It's more used to make it more viewable in a webpage (and technically more correct), because it sees it as a text document instead of an HTML page.

Alternatively, you can use string.gmatch and compare each version number individually. This works with strings like "1.0.1".

function isOutdated(current, remote)
    local cfunc = current:gmatch("%d+")
    local rfunc = remote:gmatch("%d+")
    local cnum = tonumber(cfunc())
    local rnum = tonumber(rfunc())
    while cnum and rnum do
        if cnum ~= rnum then
            return cnum < rnum
        end
        cnum = tonumber(cfunc())
        rnum = tonumber(rfunc())
    end
    return rnum ~= nil
end