使用大写+小写混合词的文件夹中的递归搜索？

hello guys i have search a lot, and iam trying to make that working. The following script searches recursive for the files into all folders.

if(isset($_POST['cmdsearch']))
{
$search = $_POST['search'];
    if (@get_magic_quotes_gpc())
    {
    $search = stripslashes($search);
    }
$it = new RecursiveDirectoryIterator("jpg");

foreach(new RecursiveIteratorIterator($it) as $file) 
    {
       if (false !== stripos($file, $search))
       {

       echo "<a style='padding:10px 10px 5px 5px; text-decoration:none; line-height:15px;' class='smamal' target='_blank' href='http://www.domain.com/files/";
       echo $file;
       echo "'>";
       echo "www.domain.gr/files/";
       echo $file;
       echo "</a>";
       echo "<br />";
       }
   }  
}
else
{
echo "<p></p>";
}

WHAT I WANT TO ADD:

1. [Important] I want to search in files both for Upper & Lower Case letters. example: right now if you search for "Drink" it gives only "Drink" not "drink".
2. Also if it is possible to search also for the 4 first letters of a given word example: search for "headphones" results= "headphones" "headline" "headless" etc...

i am trying to add into the code something like this

/\b([a-z]+[A-Z]+[a-zA-Z]*|[A-Z]+[a-z]+[a-zA-Z]*)\b/

thanks for your time.

Why don't convert search and filename to lowercase. This way you will get case-insensitive matches. Another option is to set the flag i for case-insensitive matches in regular expressions. For matching the first four characters use substr on both strings before comparing them.

If you really search large datasets think about using something like elastic search. This will even provide you fuzzy search (e.g. heaflines will also return results for headlines).

http://www.elasticsearch.org/

i think this is what i need to embed in my code. a function to convert all accent characters and then make them lowercase. both in FILENAME AND SEARCH but i have no idea how to embed it. please any help?

function normaliza ($string){ 
    $a = 'ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞ 
ßàáâãäåæçèéêëìíîïðñòóôõöøùúûýýþÿŔŕ'; 
    $b = 'aaaaaaaceeeeiiiidnoooooouuuuy 
bsaaaaaaaceeeeiiiidnoooooouuuyybyRr'; 
    $string = utf8_decode($string);     
    $string = strtr($string, utf8_decode($a), $b); 
    $string = strtolower($string); 
    return utf8_encode($string); 
}