Rename files in directory

From Sum-e Wiki

<?php

// skrypt ten zmienia nazwy plikow z np _MG_1233.JPG na IMG_1233.JPG

class Rename
{
    function __construct()
    {   
        // read directory
        $dir = scandir( '.' );
        foreach( $dir as $file )
        {   
            if ( substr( $file, 0, 1 ) == '_' and substr( $file, 9, 11 ) == 'JPG' )
            {   
                $new_name = 'I'. substr( $file, 1, 11 );
                echo "$file => $new_name \n";
                rename( $file, $new_name );
            }
        }
    }
}