url_replace.php

<?php
 
// Because PHP_URL_* constants are sequential :-(
const URL_SCHEME   = 0x01;
const URL_USER     = 0x02;
const URL_PASS     = 0x04;
const URL_HOST     = 0x08;
const URL_PORT     = 0x10;
const URL_PATH     = 0x20;
const URL_QUERY    = 0x40;
const URL_FRAGMENT = 0x80;
 
function url_replace($url, $components, callable $callback)
{
    $map = [
        URL_SCHEME   => 'scheme',
        URL_USER     => 'user',
        URL_PASS     => 'pass',
        URL_HOST     => 'host',
        URL_PORT     => 'port',
        URL_PATH     => 'path',
        URL_QUERY    => 'query',
        URL_FRAGMENT => 'fragment',
    ];
 
    if (!$parts = parse_url($url)) {
        return $url;
    }
 
    foreach ($map as $component => $key) {
        if ($components & $component) {
            $parts[$key] = $callback($parts[$key], $component);
        }
    }
 
    $result = '';
 
    if (isset($parts['scheme'])) {
        $result = $parts['scheme'] . ':';
    }
 
    if (isset($parts['host'])) {
        $result .= '//';
 
        if (isset($parts['user'])) {
            $result .= $parts['user'];
 
            if (isset($parts['pass'])) {
                $result .= ':' . $parts['pass'];
            }
 
            $result .= '@';
        }
 
        $result .= $parts['host'];
 
        if (isset($parts['port'])) {
            $result .= ':' . $parts['port'];
        }
    }
 
    if (isset($parts['path'])) {
        $result .= $parts['path'];
    }

    if (isset($parts['query'])) {
        $result .= '?' . $parts['query'];
    }

    if (isset($parts['fragment'])) {
        $result .= '#' . $parts['fragment'];
    }
 
    return $result;
}
 
$url = 'http://test.com/test-one,two three?a=b#bla';
 
echo url_replace($url, URL_PATH, function($path) {
    return '/foobar';
});