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Apache can be set up to log all sorts of information. As of Apache 2.2 the basic log file format that a fresh install of Apache will produce will have the following format:

%h %l %u %t "%r" %>s %b

Which doesn't mean a lot to the uninitiated, so here is a short explanation of each.

If you have a site with parts of it using SSL, but want to turn it off for mundane pages like the blog section then use the following code. This uses the $_SERVER['HTTPS'] variable to see if HTTPS is turned on, if it is then a header is issued and the page redirected.

if ($_SERVER['HTTPS'] == 'on') {
    $url = "http://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
    header('Location: ' . $url, true, 301);
    exit();
}

You can turn it back on again on your secure pages using the opposite.

if ($_SERVER['HTTPS'] != 'on') {
    $url = "https://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
    header('Location: ' . $url, true, 301);
    exit();
}

Don't include both of these scripts on the same page or you will break the site! Also, make sure that no headers have been issued before hand as this code can cause a "headers already issued" error.

Converting an array of information into a string is easy, but when you are doing this for insertion into a database having trailing commas is going to mess up your SQL statements.

Take the following example, which takes an array of values and converts them into a string of values. This practice is quite common in PHP database manipulation.

$values = array('one', 'two', 'three', 'four', 'five');
$string = '';
 
foreach ( $values as $val ) {
    $string .= '"'.$val.'", ';
}
 
echo $string; // prints "one", "two", "three", "four", "five",

Obviously we need to strip the trailing comma from the end of this string. To do this you can use the following function.

I had the need to create a time selecting component for a form, but I didn't want to have lots of extra components. After a little bit of searching about I found the following JQuery UI plugin called timepicker.

This plugin will take a input box as the argument and will add three selection boxes for hours, minutes and seconds. It will then hide the original input box.

However, there were two things that I needed that this plugin didn't do. The first is that it was in a 12 hour format and the second is that the plugin didn't have a second selection. So I decided to adapt that plugin in order to incorporate these things.

Here is the modified plugin.

I have already talked about a JavaScript function that rounds To the nearest number, but this was only useful if the number needed to be to the nearest 10 (or factor of). The following function is similar, but will round the number to the nearest 5 or 10, depending which is closer.

function round5(x)
{
    return (x % 5) >= 2.5 ? parseInt(x / 5) * 5 + 5 : parseInt(x / 5) * 5;
}

Use the function like this:

alert(round5(12)); // returns 10
alert(round5(14)); // returns 15

The JavaScript Math.round() function will round a decimal to the nearest whole number, but I found that I needed was to round a number to the nearest 10. So after a bit of thinking I realised that I could divide the value by 10, round it using the round() function and then multiply the result by 10.

So taking it a step further I decided to create a function that would round a number to the nearest 10, 100, 1000 or whatever value is entered. If this value is less than 0 then do the reverse by multiplying and dividing the number by the given value of accuracy. Here is the function.

function roundNearest(num, acc){
    if ( acc < 0 ) {
        num *= acc;
        num = Math.round(num);
        num /= acc;
        return num;
    } else {
        num /= acc;
        num = Math.round(num);
        num *= acc;
        return num;
    }
}

Here are some tests of the function.

A prime number is a number which has exactly two distinct number divisors: 1 and itself. So if you take the number 11, it can only be divided to get a whole number if it is divided by 1 or 11. If any other number is used then a fraction is always found.

The following function uses a method called trial division to detect if a number is prime or not.

To redirect from HTTPS to HTTP on the home page only using the following rule.

RewriteCond %{HTTPS} on
RewriteRule ^/?$ http://%{SERVER_NAME}/ [R=301,L]

The variable %{HTTPS} will be either "on" or "off" and will be enabled even if SSL is not installed on your site. The rule above sees that HTTPS is on and redirects the home page to the HTTP version. You can even chain lots of rules together like this.

RewriteCond %{HTTPS} on
RewriteRule ^/?$ http://%{SERVER_NAME}/ [R=301]
RewriteRule ^inner/directory/?$ http://%{SERVER_NAME}/inner/directory/ [R=301,L]

Note that you should end your last rule with L so that no other rules on the page are run. Also, you need to make absolutely sure that you are not redirecting any pages that are integral to the security of your shopping cart as this will turn off HTTPS for those pages.

PHP TestFest 2009 is a series of events that you can go to and learn how to test PHP and make new friends and contacts in the PHP community.

One thing that concerned me was that writing these tests might require a in depth knowledge of C++ but this is not the case. Each test is just writing a few lines of PHP code (preferably no more than 10) which will have a known outcome. The tests will be run and the output compared to the expected outcome. For more information about writing tests please refer to the phpt test basics page from the PHP site.

Disemvoweling is a technique used on blogs and forums to censor any post or comment that contains spam or other unwanted text. It involves simply removing the vowels from the text so that it is almost, but not entirely, unreadable.

Use the following function to disemvowel a string of text.

function disemvowel($string)
{
    return str_replace(array('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'), '', $string);
}

As an example, the first sentence on this post:

Disemvoweling is a technique used on blogs and forums to censor any post or comment that contains spam or other unwanted text.

would appear like this: