I've taken a bit of a memcache script that i've used previously without issue, but on the new page, I don't get any response.
the memcache is in a function which is included from another page.
what I do is put the md5 hash the mysql query and store that as the key for the memcached data. if the key isn't in memcache, then I go, create the data, put it into memcache and return it.
I think the code is fairly simple. Here are the important bits (it's a large page creating the output, so you don't need all that, though the 'return' I think is important as I fear that might be where I'm screwing up.
I call the function with
$outList.= outData($getList);
where $getList is a mysql query
The $outList function is
<?php
#$memcache = new Memcache;
#$memcache->connect("localhost",11211);
function outData($getList)
{
$memVal = #$memcache->get(MD5($getList));
if($memVal=='')
{
$results=mysql_query($getList)or die(mysql_error());
// then I do a bunch of stuff with the data
#$memcache->set(MD5($getList), $memVal, false, 60000);
}
return $memVal;
}
I can display all the stuff to create $memVal, but i suspect the error is in the if line, but the same code is used on another page without issues.
Anything look wrong with this?
with all those #'s suppressing errors, there's no way to know what is failing.
I ran it - sans the #'s and the answer popped right up though - on the line:
$memVal = #$memcache->get(MD5($getList));
#Notice: Undefined variable: memcache in /home/topbit/736160.php on line 9
Where does it get the variable $memcache ? It's not passed into the function.
The problem is scope. When in a function, variables in global scope do not automatically get passed on, you will have to add them as parameters to the function.
function outData($memcache, $getList)
Related
I would like to encode a php page which contains some php functions.
For example, I have a page named: code.php with this functions:
<?php
function data(){
echo "foo";
...
}
function storage(){
echo "storage files..";
...
}
?>
I use these functions in my other php pages and I would like to protect them by other users. How can I encode their code?
I read about base64_encode() but the examples only show how to encode a string: how can I use this solution to encode and decode my php functions?
Thank you!
If you want to stop others from seeing your PHP code you can either make it as hard as possible (via minifying, obfuscating, whatever you wish to call it) or encrypt it.
There's an answer right here on SO with a few suggestions and another I'd add is ion cube.
With encrypted code you're likely to need further changes to your web server such as an apache module. With obfuscation it will just make it harder for the other developers to read, for instance changing variables and functions names to something meaningless and hard to read.
You will inevitably need to keep a copy of your unobfuscated PHP so you can work on it in a sane manner, which may be hard if you're only developing on your server.
To use Base64 you're probably thinking of doing something like this:
eval(base64_decode('ZnVuY3Rpb24gZGF0YSgpew0KZWNobyAiZm9vIjsNCn0NCmZ1bmN0aW9uIHN0b3JhZ2UoKXsNCmVjaG8gInN0b3JhZ2UgZmlsZXMuLiI7DQp9DQokZGF0YSA9ICdkYXRhJzsNCiRzdG9yYWdlID0gJ3N0b3JhZ2UnOw=='));
What's happening here is the Base 64 string is actually valid PHP, and you first decrypt it the eval it. An example of what the decoded string might look like:
function data(){
echo "foo";
}
function storage(){
echo "storage files..";
}
$data = 'data';
$storage = 'storage';
After the above eval call you would then do something like:
// call the data function
$data();
// call the storage function
$storage();
As stated from the documentation:
PHP supports the concept of variable functions. This means that if a
variable name has parentheses appended to it, PHP will look for a
function with the same name as whatever the variable evaluates to, and
will attempt to execute it.
So, calling $someVariable() will try to run a function named whatever $someVariable contains. If you set $someVariable to foo, it would try to run foo(), if you set $someVariable to sausage, it would try to run sausage() and so on.
Obviously bear in mind that you need to make sure these function variables' names aren't going to be used elsewhere.
I have a PHP script that can take a few minutes to be done. It's some search engine which executes a bunch of regex commands and retrieve the results to the user.
I start by displaying a "loading page" which does an AJAX call to the big processing method in my controller (let's call it 'P'). This method then returns a partial view and I just replace my "loading page" content with that partial view. It works fine.
Now what I would like to do is give the user some information about the process (and later on, some control over it), like how many results the script has already found. To achieve that, I do another AJAX call every 5 seconds which is supposed to retrieve the current number of results and display it in a simple html element. This call uses a method 'R' in the same controller as method 'P'.
Now the problem I have is that I'm not able to retrieve the correct current number of results. I tried 2 things :
Session variable ('file' driver) : in 'P' I first set a session variable 'v' to 0 and then update 'v' every time a new result is found. 'R' simply returns response()->json(session('v'))
Controller variable : same principle as above but I use a variable declared at the top of my controller.
The AJAX call to 'P' works in both cases, but everytime and in both cases it returns 0. If I send back 'v' at the end of the 'P' script, it has the correct value.
So to me it looks like 'R' can't access the actual current value of 'v', it only access some 'cached' version of it.
Does anyone have an idea about how I'm going to be able to achieve what I'd like to do? Is there another "cleaner" approach and/or what is wrong with mine?
Thank you, have a nice day!
__
Some pseudo-code to hopefully make it a bit more precise.
SearchController.php
function P() {
$i = 0;
session(['count' => $i]); // set session variable
$results = sqlQuery(); // get rows from DB
foreach ($results as $result) {
if (regexFunction($result))
$i++
session(['count' => $i]); // update session variable
}
return response()->json('a bunch of stuff');
}
function R() {
return response()->json(session('count')); // always returns 0
}
I would recommend a different approach here.
Read a bit more about flushing content here http://php.net/manual/en/ref.outcontrol.php and then use it.
Long story short in order to display the numbers of row processed with flushing you could just make a loop result and flush from time to time or at an exact number or rows, the need for the 5 seconds AJAX is gone. Small untested example :
$cnt = 0;
foreach($result as $key => $val) {
//do your processing here
if ($cnt % 100 == 0) {
//here echo smth for flushing, you can echo some javascript, tough not nice
echo "<script>showProcess({$cnt});</script>";
ob_flush();
}
}
// now render the proccessed full result
And in the showProcess javascript function make what you want... some jquery replace in a text or some graphical stuff...
Hopefully u are not using fast_cgi, beacause in order to activate output buffering you need to disable some important features.
I believe you have hit a wall with PHP limitations. PHP doesn't multithread, well. To achieve the level of interaction you are probably required to edit the session files directly, the path of which can be found in your session.save_path global through php_info(), and you can edit this path with session_save_path(String). Though this isn't recommended usage, do so at your own risk.
Alternatively use a JSON TXT file stored somewhere on your computer/server, identifying them in a similar manner to the session files.
You should store the current progress of the query to a file and also if the transaction has been interrupted by the user. a check should be performed on the status of the interrupt bit/boolean before continuing to iterate over the result set.
The issue arises when you consider concurrency, what if the boolean is edited just slightly before, or at the same time, as the count array? Perhaps you just keep updating the file with interrupts until the other script gets the message. This however is not an elegant solution.
Nor does this solution allow for concurrent queries being run by the same user. to counter this an additional check should be performed on the session file to determine if something is already running. An error should be flagged to notify the user.
Given the option, I would personally, rewrite the code in either JSP or ASP.NET
All in all this is a lot of work for an unreliable feature.
I am actually trying to monitor a PHP variable (may be as a separate thread but not possible in PHP) and fire a PHP function whenever the value of the variable changes.
eg: lets take a variable $_GLOBALS['foo']=1;
if at any point in the code, the value of $_GLOBALS['foo'] changes to something else, i want to fire a PHP function immediately.
The variable can be anywhere inside a loop or in a function,etc.
Why i want this: I have a variable which stores the last error occured as a text. If the value of the variable changes from "" to something else, i want to trigger an error. My LOGIC may seem a bit strange but this is what i would like to do.
Thanx in advance.
Edit: I tried: How to use monitors in PHP? and How can one use multi threading in PHP applications but does not seem to solve the problem.
The Code (Thought this could solve some of your doubts on my question):
public function addtag($tagarray,$uid,$tagtype="1")
{
$dbobj=new dboperations();
$uiobj=new uifriend();
$tagid=$uiobj->randomstring(30,DB_SOCIAL,SOCIAL_TAG,tag_tagid);
$c=0;
foreach($tagarray as $tags)
{
$c++;
$tagname=$tags["tagname"];
$taguid=$tags["tagid"];
$dbobj->dbinsert("INSERT INTO ".SOCIAL_TAG." (".tag_tagid.",".tag_fuid.",".tag_tuid.",".tag_tagname.",".tag_tagtype.") VALUES
('$tagid','$uid','$taguid','$tagname','$tagtype')",DB_SOCIAL);
}
if($c==0)
{
$lasterror="No tags were added";return "";
}
else
{
return $tagid;
}
}
Here, if i call a error handling function instead of monitoring the variable, it wont be advisable in my case since the error handling function may do any operation like give alert and redirect to a page or any similar operation.
I asked this question cause, i thought what if the script does not reach the line
return "";
It would affect the project's workflow. Thats what i am worried about.
And the variable i was talking about is $lasterror and i have many functions like this where $lasterror is used.
I saw this, so I built this:
https://github.com/leedavis81/vent
Should solve your problem.
There is no built-in way to do this in PHP, and there's no easy way to add it. It doesn't really feel right for the way the language works anyway.
Instead of setting a variable, you could build a custom function that handles the error - or use PHP's built-in error handling functionality using a custom error handler.
Another error handling method which comes close to what you want to do (I think) is exceptions.
This is a bit of an oddity for me. PHP is my forte, and I can normally figure out any issue I encounter.
I have a custom framework that I have been using for years. I have taken it upon myself to rewrite it, and I'm doing everything essentially the same that I was before. The problem lies in the following construct:
function ModPages_GetPage() {
$page = ModPages_GetPageByName($_GET['page_name']);
if($page != false) {
include(TPL_DIR.'pages/pages.view.php');
} else {
ErrorMessage('Invalid Page', 'The selected page could not be found.');
}
}
function ModPages_GetPageByName($page_name = null) {
$db = new Database;
$query = '
SELECT *
FROM pages
WHERE page_name = "'.CleanStr($page_name).'"
AND page_enabled = "yes"
LIMIT 1
';
$page = $db->GetRow($query);
return $page;
}
This code is being called with 'home' for the value of $_GET['page_name']. The call to ModPages_GetPageByName() is working fine, but the value of $page in ModPages_GetPage() isn't getting set. Matter of fact, any debugging statements thrown in after that call are failing to display anything.
I have display_errors set to on, and error_reporting set to E_ALL. I get a couple notices from my Database class, but that's it.
Running the script at a shell fails to produce any errors. When using strace, I do see the process spits out an 'exit_group(255)'.
This one has me quite baffled. I could sure use some direction on this.
I would think it's your query, shouldn't you just return the page name instead of star? as star (*) would return an array which is probably being passed back as the value? just my guess.
$query = '
SELECT *
FROM pages
WHERE page_name = "'.CleanStr($page_name).'"
AND page_enabled = "yes"
LIMIT 1
';
if you do a print_r on the $page return I would think it should be an array
$page = $db->GetRow($query);
echo "Page:<pre>".print_r($page,true)."</pre><br />\n";
Then maybe return something like this
return $page['page_name_field'];
ok before we get to a solution can we first make sure that before setting the $page variable, first just echo $_GET['page_name'] to see if there is a value being received.
PK
Does your script stop right after your database call, or just doesn't display any output?
If the first is true, then it looks like a fatal error. With E_ALL, it should be displayed, are you sure both display_errors and error_reporting are as you say at that point, and that the GetRow function doesn't alter them in any way? If so, maybe there's something in the Apache error log (PHP errors are sometimes logged there).
If the latter is true I'm thinking about an exception being thrown in a method that is being called, and caught in a higher level function. To check this you can put the database call (ie: the point where things go wrong) inside a try/catch block and see if you reach the catch block.
I would try following:
replace $_GET with $_REQUEST (maybe your form is using POST?)
do a print_r to check contents of your variables.
use mysql_error to view any errors, or print your mysql query in your browser, copy/paste it in phpmyadmin, is it returning anything? error.. data?
something similar happend to me once, my framework was encoded in ANSI and my calling php file was UTF8+BOM... I changed everything to UTF8+BOM and it worked.
try also different browser, I know it might not be a browser problem, but it might be that your script is cached somewhere.
are you using some caching? like eaccelerator?
Are those functions in a class? If so, you will need $page = $this->ModPages_GetPageByName().
Also I would echo out the argument and the sql statment in ModPages_GetPageByName(). This way you can verify that it isn't a SQL error.
I can't say for sure why your code isn't working, but I can make some suggestions that might help in locating the error.
The first thing I notice is you don't check that $db actually contains a valid database. I don't know the details of your Database object but I'm assuming there's some mechanism in there for checking if it's actually connected to the database. You should use that to determine if the database is connected before running queries on it.
$db = new Database ();
if ($db -> isConnected ())
{
$query = 'SELECT * (etc etc etc)';
// ...
}
else
{
// Put some kind of DB connection error notification or throw an exception here
}
Just on a stylistic note, you don't need to store the results of your DB lookup before returning it, unless you're planning on doing some processing on the result before returning it. You can just return the lookup directly. Of course that's just a stylistic choice, but it saves a line or two :)
return ($db->GetRow($query));
After you run your getpage function, I'd strongly recommend var_dump()ing the result. Even if your function returned NULL, you'll still see this in the var_dump. If in doubt, dump it out :). I'd also recommend installing xdebug to make the var_dump output more readable.
$page = ModPages_GetPageByName($_GET['page_name']);
var_dump ($page);
I would also strongly recommending var_dumping your query before you execute just to make absolutely sure that you're running the query you think you're running. Copy and paste the outputted query into sqlyog or phpmyadmin or whatever you use for interactive access to your database and make sure it returns what you think it should return.
Other things to check, is the page you're trying to return actually set page_enabled='yes'? Does the page_enabled column actually store the value as 'yes', or is it a bool or an integer or something else? Is magic quotes enabled or disabled? If they're in one state when you think they're in the other they can cause confusion. Are errors actually being reported to the browser? Add a line at the top of your script that's guaranteed to fail just to make sure, like an attempted foreach on an integer. If you don't see an error, then maybe error reporting isn't configured properly. I know those are obvious questions but I also know how easy it is to overlook the obvious if you're not getting what you expect out of a query.
Are you sure $page is not set, or is it just that your debug instructions don't print anything? Try logging to a file or a database instead; maybe your code triggered output buffering or something like that.
Also, you are calling ModPages_GetPageByName before declaring it. That is usually okay, but might not be in special circumstances (e.g. when the code is wrapped in an if block). Try swapping the two.
Also, check your environment and disable opcode caching and other possible error sources. APC for example can call the old version of the script long after you changed the PHP file.
While some of you have put extra effort into responding to this, nobody has been able to see the full picture, even given the details I have provided. I have been unable to trace the issue back to its source, but have moved on to a different project.
This may be a silly question, but how do I save variables that are not specific to a particular session. An simple example of why you might want to do this would be a visitor counter - a number that increases by one each time someone visits a web page (note - I'm not actually doing that, my application is different, but that is the functionality I need). The only ways I can think of doing this are either writing the variables to a file, or putting the variables into a database. Both seem a bit inelegant. Is there a better way to to this kind of thing?
If you need to save global state, you need to save global state. This is typically done in either a file or a database as you already noted.
It's not "inelegant" at all. If you need to save something (semi-)permanently, you put it in a database. That's what databases are for.
Have a look at the serialize() function in PHP http://uk3.php.net/serialize where you'll be able to write an array or such to a file and re-retrieve:
<?php
// Save contents
$var = array('pageCounter' => 1);
file_put_contents('counter.txt', serialize($var));
// Retrieve it
$var = unserialize(file_get_contents('counter.txt'));
?>
Otherwise save the value to a database.
Given that PHP is stateless and that each pageload is essentially re-running your page anew, if you're going to be saving variables that will increment over multiple pageloads (e.g., number of distinct users), you'll have to use some form of server-end storage - file-based, database, whatever - to save the variable.
You could try installing APC (Alternative PHP Cache) which has cool features for sharing data between all PHP scripts, you could try using shared memory too or like you said, use a file or database
I think I've found the answer - session_name('whatever') can be used to have a fixed name for a session, I can refer to that data as well as the session specific session.
If you want it to be permanent, database and files are really your only two choices.
If you only want to temporarily store these values in memory, if APC is installed, you can do this:
// Fetch counter value back from memory
$success = false;
$counter = apc_fetch('counter', &$success);
if ($success) {
// fetch succeeded
} else {
// fetch failed
$counter = 0;
}
// Increment the counter and store again
// Note that nothing stops another request/page from changing this value
// between the fetch and store calls.
$counter++;
apc_store('counter', $counter);
That was just an example.
For a counter, you're better off using apc_inc('counter') / apc_dec('counter').
Presumably other opcode caches have similar methods. If you're not running an opcode cache... really? You want PHP to recompile a page every time its requested?
Elegant, no database and no file ?
Store it in your server memory with shmop and hope your server does not reboot !