generating random codes

Posted on 16th Feb 2014 07:03 pm by admin

Hi guys n gals,

I have a requirement to generate 250,000 unique codes...

These codes are for a tracking service and will be stored in the database (table field has a unique index).

Now I am working on the assumption this must work on the command line as the script will take a long time to complete... here is the salient pat of my code...

Code: <?php
...
function appendToCode( &$val , $key , $append )
{
$val = $val . $append;
}

$chars = "ABCDEFGHJKLMNPQRSTUVWXYZ";
$charend = strlen ( $chars );

$date = date ( 'md' );

$month = $date[0].$date[1];
$year = $date[2].$date[3];

$datecode = $chars[$month] . $chars[$year[0]] . $chars[$year[1]];
$codes = array();
$no_codes = isset( $_GET['no_codes'] ) ? $_GET['no_codes'] : 250000;
$codecount = 0;

do
{
for ( $j = $codecount ; $j < $no_codes ; $j++ )
{
$trackcode = NULL;
for ( $i = 0 ; $i < 7 ; $i++ )
{
$trackcode .= $chars[rand( 0 , $charend - 1 )];
echo ( time() - $start ) . PHP_EOL;
}
$codes[] = $trackcode . $date;

}
//$t = count($codes);
//echo 'Codes Generated: ' . $t . PHP_EOL;
//echo 'Last Code: ' . $codes[--$t] . PHP_EOL;

$codes = array_unique( $codes );
$codecount = count ( $codes );

//echo 'Unique Codes: ' . $codecount . PHP_EOL;
// the following statement prevents infinite loop in dev mode...
if (
(time() - $start) > 150
)
{
break;
}


} while ( $codecount < ($no_codes) - 1 );
...
The last characters of the code relate to the date - as these codes will only be developed every now and then - not a frequent occurrence and will allow a check on the database to see if codes ending in that 3 character string exist...

What I am asking is, is there a more efficient method of performing this operation.

Any tips would be most welcome.

Your Answer:

Login to answer

Other forums

image upload script not working with png
The basic process of this php code is to take the submitted file, convert it to a small JPG thumbnai

Output Buffering question
Hi all,

I've been trying to wrap my head around output buffering. So far I've found tons of

Take info from one coloum and move to another
Hi all,

I have this:
Code: [Select]$array = "SELECT stock_id FROM stocks WHERE stock_

Renaming a file that a user uploads to site?
My site allows for registered users to upload images to the site under their own gallery. Currently

Why does this file not return file names that start with numbers?
This file returns a list of filenames to help populate a drop down in my form. For some reason it ig

Why do I get this error
Parse error: syntax error, unexpected T_STRING, expecting ',' or ';' in /home/a5488351/public_html/b

mail() says sent but no email received
My code is quite simple:

Code: <?php
$to = "Ty44ler@yahoo.com";
$subje

pull content
I have an existing page, domain/adverts.php which has a good PR. I've just rebuilt my site and the n

compile php5 with DOM
Hi,

I can't manage to compile php 5.3.0 from source on Windows to include DOM,
in spite of

Timer control causing error
I recently decided to add a timer control to an existing page that uses AJAX on my site. As soon as