PHP - Rand()

Hi,   I basically want a function that takes a parameter which is a percentage chance of the functioning returning true. A user can move from tier 1->10 and at tier 1 there's a 70% chance to move to tier 2, from tier 2 there's a slightly less chance to move up, and so on.   I tried with the following piece of code:  

public function rollTheDice($winnerPercentage)
{
$number = rand(1, 100);
if ($number <= $winnerPercentage)
return true;
return false;
}

  The above code makes logical sense to me: 1. Pick a random number between 1 and 100. 2. If that number is less than or equal to the percentage, then we passed (example, if the random number is less than or equal to 70.. there must be a 70% chance of this?)   This however does not seem to work, in fact it appears that when simulating a roll, 70% fails at the very first step (where there is a 70% chance of winning..) To actually make it to tier 10, has yet to be accomplished, so by simulating this with unlimited attempts for 120 seconds straight doesn't seem to "win".   I tried (just for fun) and change the if-statement so: if ($number >= $winnerPercentage)   This seems to be working quite well, as the simulator quickly reaches tier 10 this way. Any suggestions to code changes, or can someone explain why it is working way better when exchanging less than with greater than?

Hey guys,

I don't know what to do. I've got a script used for gamble:


$gamble_rand = rand($number_of_tickets,$gamble_chance);
if($gamble_chance == $gamble_rand){


If $number_of_tickets is set by 99 and $gamble_chance is set by 100 the chance is 1:100 that the If-Clause is not true. But it seems to me that PHP is making its on "random". Independent of the values PHP is interpreting that 20 times of 100 times the correct logic is false...

If $number_of_tickets is set by 1 there's no big different. Its just a little bit less, but not the chance that it has to be.

Thanks for helping and Merry Christmas :-)

Hi,   I'm having a bit of trouble. I want to order the same 9 results by RAND(). Currently I have them ordered by 'avg' (average views) and that's working fine, but when I add a sub query to make those 9 results scatter by random it's causing some trouble.   Code I currently have that works:

 
$sql = "SELECT *, views / HOUR(TIMEDIFF(NOW(), date)) as avg
    FROM content
    WHERE date BETWEEN CURDATE() - INTERVAL 30 DAY AND NOW() - INTERVAL 2 HOUR
    AND views > 600 
    AND live = '0'
    ORDER BY avg DESC
    LIMIT 9";
 

 

I have 2 sites here that does what i need them to do but i dont know how to put the 2 codes together 

i got it to upload all files and used rand() to give the files a # but it ends up giving them all the same # lol so they overwrite them selfs lol


This site shows how to upload mltiple fiels with php.
http://www.ehow.com/how_6345068_upload-multiple-files-php.html


This site shows how to rename only 1 file uploaded with rand()
http://php.about.com/od/advancedphp/ss/rename_upload.htm


i pray this is not to hard to do and if any one gets bored after words can you show how to block a file type from being
uploaded ? like php/exe types

PS)i would call my self a php newbe lol and ty you for your time and help

Code from http://php.about.com/od/advancedphp/ss/rename_upload.htm

Code: [Select]
<form enctype="multipart/form-data" action="upload.php" method="POST">
Please choose a file: <input name="uploaded" type="file" /><br />
<input type="submit" value="Upload" />
</form>


//This function separates the extension from the rest of the file name and returns it 
function findexts ($filename)
{ $filename = strtolower($filename) ;
$exts = split("[/\\.]", $filename) ;
$n = count($exts)-1; $exts = $exts[$n];
return $exts;
}

//This applies the function to our file 
$ext = findexts ($_FILES['uploaded']['name']) ;

//This line assigns a random number to a variable. You could also use a timestamp here if you prefer. 
$ran = rand () ;
//This takes the random number (or timestamp) you generated and adds a . on the end, so it is ready of the file extension to be appended.
$ran2 = $ran.".";
//This assigns the subdirectory you want to save into... make sure it exists!
$target = "images/";
//This combines the directory, the random file name, and the extension
$target = $target . $ran2.$ext;
if(move_uploaded_file($_FILES['uploaded']['tmp_name'], $target)) {
echo "The file has been uploaded as ".$ran2.$ext; }
else {
echo "Sorry, there was a problem uploading your file.";
}
The code from http://www.ehow.com/how_6345068_upload-multiple-files-php.html

Code: [Select]
<form action="upload.php" method="post" enctype="multipart/form-data">
File: <input type="file" name="file[]"/><br/>
File: <input type="file" name="file[]"/><br/>
File: <input type="file" name="file[]"/><br/>
<input type="submit" name="submit" value="Upload"/>
</form>



$destpath = "upload/" ;


while(list($key,$value) = each($_FILES["file"]["name"])) {
if(!empty($value)){
f ($_FILES["file"]["error"][$key] > 0) {
echo "Error: " . $_FILES["file"]["error"][$key] . "<br/>" ;
}
else {
$source = $_FILES["file"]["tmp_name"][$key] ;
$filename = $_FILES["file"]["name"][$key] ;
move_uploaded_file($source, $destpath . $filename) ;
echo "Uploaded: " . $destpath . $filename . "<br/>" ;
}
}
}

This topic has been moved to MySQL Help.

http://www.phpfreaks.com/forums/index.php?topic=326563.0

I want to use the following code to upload images to my server (below code works great)

Code: [Select]
<?php
$rand = rand(1,99999999999999);
$member_id = $_SESSION['SESS_MEMBER_ID'];

if(isset($_FILES['uploaded']['name']))
{
    $target = "gallery/";
$allowed_filetypes = array('.jpg','.gif','.bmp','.png');
$max_filesize = 524288; // Maximum filesize in BYTES (currently 0.5MB) 
    $fileName = basename($_FILES['uploaded']['name']);
    $target = $target . $fileName;
$errors = array();

   // Get the extension from the filename.
   $ext = substr($filename, strpos($filename,'.'), strlen($filename)-1); 
 
   // Check if the filetype is allowed.
   if(in_array($ext,$allowed_filetypes))
    {
         $errors[] = "The file you attempted to upload is not allowed.";
    }
    
// Now check the filesize.
   if(filesize($_FILES['uploaded']['tmp_name']) > $max_filesize)
    {
         $errors[] = "The file you attempted to upload is too large.";
    }
  
    // Check if we can upload to the specified path.
   if(is_writable($target))
    {
         $errors[] = "You cannot upload to the specified directory, please CHMOD it to 777.";
    }
 
    //Here we check that no validation errors have occured.
    if(count($errors)==0)
    {

//Try to upload it.
        if(!move_uploaded_file($_FILES['uploaded']['tmp_name'], $target))
        {
            $errors[] = "Sorry, there was a problem uploading your file.";
        }
    }
    
    //If no errors show confirmation message
    if(count($errors)==0)
    {
         echo "<div class='notification success png_bg'>
<a href='#' class='close'><img src='img/cross_grey_small.png' title='Close this notification' alt='close' /></a>
<div>
The file {$fileName} has been uploaded<br>\n
</div>
</div>";

//echo "The file {$fileName} has been uploaded";
echo "<br>\n";
echo "<a href='gallery.php'>Go Back</a>\n";
    }
    else
    {
        //show error message
        echo "<div class='notification attention png_bg'>
<a href='#' class='close'><img src='img/cross_grey_small.png' title='Close this notification' alt='close' /></a>
<div>
Sorry your file was not uploaded due to the following errors:<br>\n
</div>
</div>";
//echo "Sorry your file was not uploaded due to the following errors:<br>\n";
        echo "<ul>\n";
        foreach($errors as $error)
        {
            echo "<li>{$error}</li>\n";
        }
        echo "</ul>\n";
echo "<br>\n";
echo "<a href='gallery.php'>Go Back</a>\n";
    }
    
}
else
{
    //Show the form
echo "Use the following form below to add a new image to your gallery;<br />\n";
    echo "<form enctype='multipart/form-data' action='' method='POST'>\n";
    echo "Please choose a file: <input name='uploaded' type='file' /><br />\n";
    echo "<input type='submit' value='Upload' />\n";
    echo "</form>\n";

//Echo Tests!
    echo "<br /><br />Random FileName: "; 
echo $rand;
echo "<br />";
echo "member ID: #";
echo $member_id;
}
?>
i then want it to rename the files for example:

"test.png" is uploaded and name changed to "92997863_321.png" (where first number is using my $rand then the "_" then second number is my $member_id)

the script already got these pieces of information and also gets the file extension using the $ext code.

can this be done, and can i also upload the new filename to my sql table?

Okay, so I'm kind of a PHP noob.   But out of context, for this site that I'm designing, it's easiest if I make a directory in the temporary folder PHP uses. In my case, /tmp/ because I am on Linux.   I want to use rand() to generate a random name for the page. But I then realized something, rand() could produce duplicates. How do I prevent PHP from trying to make the same directory at the same time? I know there are functions that will check if a file exists but I'm assuming it'll fail if that directory is currently being created, right?   How do I assure thread safety?   I willing to change my idea and not use rand(). Is there a way to get a unique key for each anonymous user on my site?