Generates a URL-friendly "slug" from an unsanitized string

gistfile1.cs

/// <summary>
/// Will transform "some $ugly ###url wit[]h spaces" into "some-ugly-url-with-spaces"
/// </summary>
public static string Slugify(this string phrase, int maxLength = 50)
{
    string str = phrase.ToLower();
    
    // invalid chars, make into spaces
    str = Regex.Replace(str, @"[^a-z0-9\s-]", "");  
    // convert multiple spaces/hyphens into one space       
    str = Regex.Replace(str, @"[\s-]+", " ").Trim(); 
    // cut and trim it
    str = str.Substring(0, str.Length <= maxLength ? str.Length : maxLength).Trim(); 
    // hyphens
    str = Regex.Replace(str, @"\s", "-"); 

    return str;
}

// slug
string title = @"A bunch of ()/*++\'#@$&*^!%     invalid URL characters  ";

return title.Slugify();

// outputs
a-bunch-of-invalid-url-characters

gistfile2.php

function generateSlug($phrase, $maxLength)
{
    $result = strtolower($phrase);

    $result = preg_replace("/[^a-z0-9\s-]/", "", $result);
    $result = trim(preg_replace("/[\s-]+/", " ", $result));
    $result = trim(substr($result, 0, $maxLength));
    $result = preg_replace("/\s/", "-", $result);

    return $result;
}

$title = "A bunch of ()/*++\'#@$&*^!%     invalid URL characters  ";

echo(generateSlug($title));

// outputs
a-bunch-of-invalid-url-characters