How to determine, using regexp or something else in PHP, that following urls match some patterns with tokens (url => pattern):

1. node/11221 => node/%node
2. node/38429/news => node/%node/news
3. album/34234/shadowbox/321023 => album/%album/shadowbox/%photo

Thanks in advance!

Update 1

Wrote the following script:

<?php

$patterns = [
    "node/%node",
    "node/%node/news",
    "album/%album/shadowbox/%photo",
    "media/photo",
    "blogs",
    "news",
    "node/%node/players",
];

$url = "node/11111/news";

foreach ($patterns as $pattern) {

    $result_pattern = preg_replace("/\/%[^\/]+/x", '/*', $pattern);

    $to_replace = ['/\\\\\*/']; // asterisks
    $replacements = ['[^\/]+'];

    $result_pattern = preg_quote($result_pattern, '/');
    $result_pattern = '/^(' . preg_replace($to_replace, $replacements, $result_pattern) . ')$/';

    if (preg_match($result_pattern, $url)) {
        echo "<pre>" . $pattern . "</pre>"; 
    }

}


?>

Could anyone analyze whether this code is good enough? And also explain why there is so many slashes in this part $to_replace = ['/\\\\\*/']; (regarding the replacement, found exactly such solution on the Internet).

If you know the format beforehand you can use preg_match. For example in the first example, you know %node can only be numbers. Matching multiples should be as as easy as we did it earlier, just store the regex in the array:

$patterns = array(
    'node/%node' => '|node/[0-9]+$|',
    'node/%node/news' => '|node/[0-9]+/news|',
    'album/%album/shadowbox/%photo' => '|album/[0-9]+/shadowbox/[0-9]+|',
    'media/photo' => '|media/photo|',
    'blogs' => '|blogs|',
    'news' => '|news|',
    'node/%node/players' => '|node/[0-9]+/players|',

);

$url = "node/11111/players";

foreach ($patterns as $pattern => $regex) {
    preg_match($regex, $url, $results);
    if (!empty($results)) {
        echo "<pre>" . $pattern . "</pre>"; 
    }
}

Notice how I added the question mark $ to end of the first rule, this will insure that it doesn't break into the second rule.

Here is the generic solution to the solution above

<?php
    // The url part
    $url     = "/node/123/hello/strText";
    // The pattern part
    $pattern = "/node/:id/hello/:test";

    // Replace all variables with * using regex
    $buffer = preg_replace("(:[a-z]+)", "*", $pattern);
    // Explode to get strings at *
    // In this case ['/node/','/hello/']
    $buffer = explode("*", $buffer);
    // Control variables for loop execution
    $IS_MATCH = True;
    $CAPTURE  = [];
    for ($i=0; $i < sizeof($buffer); $i++) { 
        $slug = $buffer[$i];
        $real_slug = substr($url, 0 , strlen($slug));
        if (!strcmp($slug, $real_slug)) {
            $url = substr($url, strlen($slug));
            $temp = explode("/", $url)[0];
            $CAPTURE[sizeof($CAPTURE)+1] = $temp;
            $url = substr($url,strlen($temp));
        }else {
            $IS_MATCH = False;
        }

    }
    unset($CAPTURE[sizeof($CAPTURE)]);
    if($IS_MATCH)
        print_r($CAPTURE);
    else
        print "Not a match";
?>

You can pretty much convert the code above into a function and pass parameters to check against the array case. The first step is regex to convert all variables into * and the explode by *. Finally loop over this array and keep comparing to the url to see if the pattern matches using simple string comparison.

As long as the pattern is fixed, you can use preg_match() function:

$urls = array (
          "node/11221",
          "node/38429/news",
          "album/34234/shadowbox/321023",
        );

foreach ($urls as $url)
{
  if (preg_match ("|node/([\d]+$)|", $url, $matches))
  {
    print "Node is {$matches[1]}
";
  }
  elseif (preg_match ("|node/([\d]+)/news|", $url, $matches))
  {
    print "Node is {$matches[1]}
";
  }
  elseif (preg_match ("|album/([\d]+)/shadowbox/([\d]+)$|", $url, $matches))
  {
    print "Album is {$matches[1]} and photo is {$matches[2]}
";
  }
}

For other patterns to match, adjust as necessary.