Making strings "URL safe"

Question

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URL Friendly Username in PHP?

Is there a way to make strings "URL safe" which means replacing whitespaces with hyphens, removing any punctuation and change all capital letters to lowercase?

For example:

"This is a STRING" -› "this-is-a-string"

or

"Hello World!" –› "hello-world"

What would be the easiest way? (I would prefer PHP to JavaScript.) — user1706680, Jan 17 '13 at 11:24
Yes, there most certainly is. [What have you tried?](http://whathaveyoutried.com) — , Jan 17 '13 at 11:26
The answer to this question is hidden away in the source code of wordpress. Look for an ajax call that creates the slug for your post basing on the title. — Prasanth, Jan 17 '13 at 11:49

kmkaplan · Accepted Answer · 2013-01-17T11:47:28.080

9

You can use preg_replace to replace change those characters.

$safe = preg_replace('/^-+|-+$/', '', strtolower(preg_replace('/[^a-zA-Z0-9]+/', '-', $string)));

edited Jan 17 '13 at 11:47

answered Jan 17 '13 at 11:31

kmkaplan

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Is there an easy way to get rid of the last hyphen when the string ends with a special character? – user1706680 Jan 17 '13 at 11:45
@user1706680 Yes. I edited the answer to get rid of heading and trailing hyphens. – kmkaplan Jan 17 '13 at 11:51

score 2 · Answer 2 · answered Jan 17 '13 at 11:29

I Often use this function to generate my clean urls and seems to work fine, You could alter it according to your needs but give it a try.

function sanitize($string, $force_lowercase = true, $anal = false) {
    $strip = array("~", "`", "!", "@", "#", "$", "%", "^", "&", "*", "(", ")", "_", "=", "+", "[", "{", "]",
                   "}", "\\", "|", ";", ":", "\"", "'", "&#8216;", "&#8217;", "&#8220;", "&#8221;", "&#8211;", "&#8212;",
                   "â€”", "â€“", ",", "<", ".", ">", "/", "?");
    $clean = trim(str_replace($strip, "", strip_tags($string)));
    $clean = preg_replace('/\s+/', "-", $clean);
    $clean = ($anal) ? preg_replace("/[^a-zA-Z0-9]/", "", $clean) : $clean ;
    return ($force_lowercase) ?
        (function_exists('mb_strtolower')) ?
            mb_strtolower($clean, 'UTF-8') :
            strtolower($clean) :
        $clean;
}

Making strings "URL safe"

2 Answers2

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