如何添加文本以防缺少回显$ _GET [复制]

Question

Possible Duplicate:
Add http:// prefix to URL when missing

I'm using this code like this:

<?php echo $_GET['i']; ?>

myweb.com/sample.php?i=http://sample.com

But I want to make sure it always has http:// just in case this is provide myweb.com/sample.php?i=sample.com

How can I make this code <?php echo $_GET['i']; ?> make sure always adds the http:// in case is missing?

Answer 1

You can check, your $_GET['i'] and accept only with http:

For example:

'http://' contains 7 chars + smallest url 'w.xx' contains 4 chars

So, minimal lenght of your $_GET[i] is 11 chars

if(!empty($_GET['i']))
{

    $len = strlen($_GET['i']);
    if($len > 10 and  substr($_GET['i'], 0, 7) === 'http://')
    {     
        [... some of your code ?]
    }
    else if ($len > 3)
    {

        //force add http://
        $_GET['i'] = 'http://'.$_GET['i'];
     }

     unset($len);
}
else
{
    $_GET['i'] = 'No url?';
}

// <-- Place for your echo